Academic literature on the topic 'Metal complexes and nanoparticles'

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Journal articles on the topic "Metal complexes and nanoparticles"

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Bharadwaj, Namita, and Jaishri Kaushik. "Nano Synthesis and Characterization of Complex Derived from Silver Metal Conjugated with Midodrine Hydrochloride." Oriental Journal Of Chemistry 37, no. 1 (February 28, 2021): 157–61. http://dx.doi.org/10.13005/ojc/370121.

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The stability constant Kf for the complexation of Ag(Ⅰ) metal ion with Midodrine hydrochloride were determinedby spectrophotometric method at room temperature .The colored complexes were measured at 300 nm. The stability constant of the complexes were found to be 5.47 by mole ratio method. The stoichiometry of the complexes formed between the Midodrine drug and Ag (Ⅰ) metal ion are 1:1 M/L ratio. Silver conjugated Midodrine hydrochloride Nano synthesized and characterized by UV/Visible spectroscopy, SEM, XRD and FT-IR. The UV/Visible spectra of Midodrine –Ag nanoparticle in the range of 322 nm. XRD conformThe crystallite size of Midodrine - Ag (Ⅰ) nanoparticles are found to be 64.5 nmfrom Debye Scherer formula.Thecrystallinity of nanoparticles is Face centered cubic structure. SEM conform of particle size and surface morphology, FTIR analyzed involvement of -NH2 group in Midodrine is the stabilized of silver nanoparticle. This research is focuses on complexation, Nano synthesis and characterization of Drug-silver nanoparticle for antihypotention therapy.
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Masilela, Nkosiphile, Edith Antunes, and Tebello Nyokong. "Axial coordination of zinc and silicon phthalocyanines to silver and gold nanoparticles: an investigation of their photophysicochemical and antimicrobial behavior." Journal of Porphyrins and Phthalocyanines 17, no. 06n07 (June 2013): 417–30. http://dx.doi.org/10.1142/s1088424613500016.

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This work reports on the axial coordination of zinc phthalocyanine and bis-(1,6-hexanedithiol) silicon phthalocyanine to silver and gold nanoparticles. Red shifting of absorption spectra of the phthalocyanine complexes was observed after conjugation with the nanoparticles. An improvement in the photophysicochemical behavior and antimicrobial activity was achieved in the presence of metal nanoparticles for both complexes. A decrease in triplet lifetimes was observed for all the phthalocyanine metal nanoparticle conjugates. The Zn phthalocyanine complex gave the highest triplet and singlet oxygen quantum yield in the presence of gold nanoparticles. On the other hand, the bacterial inhibition was found to be best for the Si phthalocyanine derivative in the presence of nanoparticles compared to the Zn phthalocyanine counterpart. The highest antimicrobial activity was achieved for both conjugates against B. subtilis compared to S. aureaus both in the dark and under illumination with light.
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Bergamini, Giacomo, and Paola Ceroni. "Metal complexes and nanoparticles for energy upconversion." Dalton Transactions 47, no. 26 (2018): 8507–8. http://dx.doi.org/10.1039/c8dt90101e.

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Revaprasadu, N., and S. N. Mlondo. "Use of metal complexes to synthesize semiconductor nanoparticles." Pure and Applied Chemistry 78, no. 9 (January 1, 2006): 1691–702. http://dx.doi.org/10.1351/pac200678091691.

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Research in materials with dimensions of the order of nanometers has made a huge impact on the scientific community in the past decade. Chemists play an important role in this area of research as they endeavor to prepare pure, crystalline, surface-derivatized nanoparticles, which can be processed in potential applications. This review describes some of the routes to nanoparticles with particular emphasis on the use of metal complexes in the preparation of high-quality nanoparticles. The synthesis of II/VI semiconductor nanoparticles such as CdSe, CdS, ZnS, and PbS using the single molecular precursor route is reviewed in detail. The synthesis of some III/V semiconductor materials is also briefly discussed. Finally, current work on the shape control of nanoparticles is described. The mechanism of growth induced by variation of reaction conditions is discussed using CdSe nanoparticles as an example.
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Savita Belwal, Sujana Kariveda, Saritha Ramagiri, Swathi A, Shubham Kute, and Suryam Goud. "The anti-malignant activity of Macrotyloma uniflorum mediated green synthesized Cu and Zn metal-ligand nano complexes." International Journal of Research in Pharmaceutical Sciences 11, SPL4 (December 21, 2020): 1573–80. http://dx.doi.org/10.26452/ijrps.v11ispl4.4340.

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The green biological route has been employed to convert macro-sized zinc and copper metal complexes into nano-sized metal complexes. These bioactive metal complexes were synthesized by template condensation process in the chemistry laboratory. The newly synthesized biologically active complexes were converted into nano range from phytochemical aqueous extract of Macrotyloma uniflorum (horse gram). Biologically converted nano complexes have been characterized by physicochemical as well as spectroscopic techniques such as UV-visible spectrophotometer and FTIR. The reduced Cu and Zn metal nanoparticles were analyzed with SEM for shape and size, which showed most of the nanoparticles, were nearly spherical with nano range size. To estimate the potentiality of newly manufactured copper and zinc nanoparticles in vitro and in in vivo studies, i.e. antifungal and antibacterial and anti-cancer activities were performed. The biogenic nanoparticles of Cu and Zn were evaluated for their activity on cancer A-549 cell lines by standard MTT assay for metabolically active mitochondria and cell viability. Further flow cytometric studies showed Cu, and Zn nano complexes had inhibition efficacy of cancer cells compared to normal cells. This study elevates that biosynthesized Cu & Zn nano complexes can be an alternative for the treatment of cancer.
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Zhou, Meng, Chenjie Zeng, Qi Li, Tatsuya Higaki, and Rongchao Jin. "Gold Nanoclusters: Bridging Gold Complexes and Plasmonic Nanoparticles in Photophysical Properties." Nanomaterials 9, no. 7 (June 28, 2019): 933. http://dx.doi.org/10.3390/nano9070933.

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Recent advances in the determination of crystal structures and studies of optical properties of gold nanoclusters in the size range from tens to hundreds of gold atoms have started to reveal the grand evolution from gold complexes to nanoclusters and further to plasmonic nanoparticles. However, a detailed comparison of their photophysical properties is still lacking. Here, we compared the excited state behaviors of gold complexes, nanolcusters, and plasmonic nanoparticles, as well as small organic molecules by choosing four typical examples including the Au10 complex, Au25 nanocluster (1 nm metal core), 13 diameter Au nanoparticles, and Rhodamine B. To compare their photophysical behaviors, we performed steady-state absorption, photoluminescence, and femtosecond transient absorption spectroscopic measurements. It was found that gold nanoclusters behave somewhat like small molecules, showing both rapid internal conversion (<1 ps) and long-lived excited state lifetime (about 100 ns). Unlike the nanocluster form in which metal–metal transitions dominate, gold complexes showed significant charge transfer between metal atoms and surface ligands. Plasmonic gold nanoparticles, on the other hand, had electrons being heated and cooled (~100 ps time scale) after photo-excitation, and the relaxation was dominated by electron–electron scattering, electron–phonon coupling, and energy dissipation. In both nanoclusters and plasmonic nanoparticles, one can observe coherent oscillations of the metal core, but with different fundamental origins. Overall, this work provides some benchmarking features for organic dye molecules, organometallic complexes, metal nanoclusters, and plasmonic nanoparticles.
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Ghavam, Mansureh, Dara Dastan, Elaheh Fadaei, and Gholamabbas Chehardoli. "Synthesis of Gadolinium Complexes Using Medicinal Plant Extracts." Avicenna Journal of Pharmaceutical Research 2, no. 2 (December 30, 2021): 44–48. http://dx.doi.org/10.34172/ajpr.2021.09.

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Background: Gadolinium compounds are used as contrast enhancers in MRI imaging. Generally, free metal ions are not used in MRI imaging due to their toxicity. To reduce the toxicity of the free form of the metal, complexing agents are employed for making nanoparticles. Due to their low toxicity and natural abundance, plant extracts having potential to function as chelating agents are good alternatives for the formation of gadolinium nanoparticles. Methods: Aqueous extracts of five plant species, including Thymus daenensis Celak, Nepeta sessilifolia Bung, Crocus sativus L., Salvia hydrangea DC. ex Benth, and Hymenocrater incanus Bunge were prepared. Five complexes were produced as the result of each extract’s reaction with gadolinium nitrate solution in the presence of 1 mM solution of NaOH. The obtained complexes were analyzed adopting the Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Energy dispersive x-ray analysis (EDAX) techniques. Results: EDAX analysis of the obtained complexes confirmed the presence of gadolinium in all complexes. Among the five complexes, the highest percentage of gadolinium (21.07) was recorded for the complex derived from the extract of H. incanus Bunge, while the lowest one (9.33) was detected for the complex derived from the T. daenensis Celak. Despite adopting various methods to disperse the complex particles in deionized water in order for determining the particle size, the high adhesion of the particles prevented the determination of the desired particle size in nanoscale. Conclusion: Although synthesizing the complexes was successful and EDAX confirmed the presence of gadolinium metal in them, SEM analysis failed to prove their nanoparticle structure. The high tendency of solid particles to adhere was found to prevent the formation of independent nanoparticles in solution.
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Lastra, Ruben O., Tatjana Paunesku, Barite Gutama, Filiberto Reyes, Josie François, Shelby Martinez, Lun Xin, et al. "Protein Binding Effects of Dopamine Coated Titanium Dioxide Shell Nanoparticles." Precision Nanomedicine 2, no. 4 (October 2, 2019): 393–438. http://dx.doi.org/10.33218/prnano2(4).190802.1.

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Non-targeted nanoparticles are capable of entering cells, passing through different subcellular compartments and accumulating on their surface a protein corona that changes over time. In this study, we used metal oxide nanoparticles with iron-oxide core covered with titanium dioxide shell (Fe3O4@TiO2), with a single layer of covalently bound dopamine covering the nanoparticle surface. Mixing nanoparticles with cellular protein isolates showed that these nanoparticles can form complexes with numerous cellular proteins. The addition of non-toxic quantities of nano-particles to HeLa cell culture resulted in their non-specific uptake and accumulation of protein corona on nanoparticle surface. TfRC, Hsp90 and PARP were followed as representative protein components of nanoparticle corona; each protein bound to nanoparticles with different affinity. The presence of nanoparticles in cells also mildly modulated gene expression on the level of mRNA. In conclusion, cells exposed to non-targeted nanoparticles show subtle but numerous changes that are consistent from one experiment to another.
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Alarcón-Correa, Mariana, Tung-Chun Lee, and Peer Fischer. "Dynamic Inclusion Complexes of Metal Nanoparticles Inside Nanocups." Angewandte Chemie International Edition 54, no. 23 (May 8, 2015): 6730–34. http://dx.doi.org/10.1002/anie.201500635.

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Alarcón-Correa, Mariana, Tung-Chun Lee, and Peer Fischer. "Dynamic Inclusion Complexes of Metal Nanoparticles Inside Nanocups." Angewandte Chemie 127, no. 23 (May 8, 2015): 6834–38. http://dx.doi.org/10.1002/ange.201500635.

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Dissertations / Theses on the topic "Metal complexes and nanoparticles"

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Zapiter, Joan Marie Diangson. "Transition Metal Complexes Anchored on Europium Oxide Nanoparticles." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/24786.

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Polypyridyl transition metal complexes containing ruthenium, rhodium and iridium centers are mainly studied due to their light absorbing and emitting properties. Lanthanide oxides such as europium oxide absorb light as well and exhibit strong luminescence and long lifetimes. The optical properties of these materials were significant especially in solar energy utilization schemes and optical applications. Energy transfer across a surface is important in several applications including phosphors and biomedical applications. Excited states of metal complexes with a carboxylate-containing ligand such as deeb = diethyl-2,2'-bipyridine-4,4'-dicarboxylate were studied on nanoparticle surfaces. In this work, [Rh(deeb)2Cl2](PF6), [Ir(deeb)2Cl2](PF6) and [Ir(deeb)2(dpp)](PF6)3 were synthesized using the building block approach. The metal complexes were characterized using 1H NMR spectroscopy, mass spectrometry, electronic absorption spectroscopy and electrochemistry. The 1H NMR spectra of the complexes were consistent with those of their ruthenium analogs. Mass spectra contain fragmentation patterns of the (M-PF6)+ molecular ion for [Rh(deeb)2Cl2](PF6) and [Ir(deeb)2Cl2](PF6), and (M-3PF6)3+ molecular ions for [Ir(deeb)2(dpp)](PF6)3. The electronic absorption spectrum of [Rh(deeb)2Cl2](PF6) shows a maximum at 328 nm, which is assigned as 1π→π*transition. The electronic absorption spectrum of [Ir(deeb)2Cl2](PF6) shows maxima at 308 nm and 402 nm, which are assigned as 1π→π* and metal-to-ligand charge transfer transitions, respectively. The [Ir(deeb)2(dpp)](PF6)3 complex exhibits peaks due to 1π→π* transitions at 322 nm and 334 nm. [Rh(deeb)2Cl2](PF6) has emission maxima from the 3LF state at 680 nm and 704 nm for the solid and glassy solutions at 77 K, respectively. [Ir(deeb)2Cl2](PF6) has emission maxima from the 3MLCT state at 538 nm in acetonitrile and 567 nm in the solid state at room temperature, with lifetimes of 1.71 μs and 0.35 μs, respectively. [Ir(deeb)2Cl2](PF6) has an unusually higher quantum yield than analogous compounds. [Ir(deeb)2(dpp)](PF6)3 has emission maxima from the 3IL state at 540 nm in acetonitrile and 599 nm in the solid state at room temperature, with lifetimes of 1.23 μs and 0.14 μs, respectively. Cyclic voltammetry of [Ir(deeb)2Cl2](PF6) and [Ir(deeb)2(dpp)](PF6)3 yield reversible and quasi-reversible couples corresponding to deeb ligand and Ir3+/+reductions, respectively. Attachment of the complexes were conducted by equilibration of complex solutions in acetonitrile with europium oxide nanoparticles. Europium oxide nanoparticles, which were synthesized by gas-phase condensation, have 11-nm diameters and exhibit sharp f-based luminescence in the visible and near IR regions. EDX, TEM, IR and reflectance spectroscopy measurements indicate substantial coating through various modes of attachment of the nanoparticle surface by the metal complexes while retaining the excited state properties of the metal complexes. Surface adsorption studies indicate monolayer coverage of the nanoparticle surface by the metal complexes, consistent with limiting surface coverages of previously reported analogous systems. Eu2O3 nanoparticles modified with [Rh(deeb)2Cl2]+ exhibit minimal to no energy transfer from emission spectra, and a reduction in the lifetime at 77K could be due to the rhodium complex preventing the excitation of Eu3+. Upon attachment of the Ir complexes [Ir(deeb)2Cl2]+ and [Ir(deeb)2(dpp)]3+ on as-prepared nanoparticles, Eu3+ luminescence was observed for nanoparticles modified with iridium complexes at room temperature, which could be due to energy transfer among other possibilities. Efficiencies of 68% and 50%, and energy transfer rate constants of 1.1 x 10-5 and 1.0 x 10-5 were calculated from lifetime data for [Ir(deeb)2Cl2]+ and [Ir(deeb)2(dpp)]3+ on Eu2O3 nanoparticles, respectively. Since iridium complexes are used as components of light-emitting diodes, europium oxide nanoparticles modified with iridium complexes have potential in optical applications which make studies of these compounds interesting.
Master of Science
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Kamras, Brian Leon. "Application-Focused Investigation of Monovalent Metal Complexes for Nanoparticle Synthesis." Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1538771/.

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Over the last 20 years, there has occurred an increase in the number, scope, and impact of nanomaterials projects. By leveraging the Surface Plasmon Resonance of metallic nanoparticles for labelling, sensing, and treatment, researchers have demonstrated the versatile utility of these nanomaterials in medicine. The literature provides evidence of use of simple, well-known chemistry for nanomaterials synthesis when the focus is new applications of nanomaterials. A case in point, is the synthesis of metallic nanoparticles, whereby HAuCl4, CuCl2, Cu(acac)2, and AgNO3 are typically employed as nanoparticle precursors. Unfortunately, the use of these precursors limits the number of applications available to these materials - particularly for AuNPs in medicine, where the byproducts of nanoparticle synthesis (most often surface-adsorbed reductants, toxic stabilizers, and growth directors) cause nanoparticles to fail clinical trials. Despite the several thousand publications detailing the advancements in nanoparticle therapeutics, as of 2017, there were only 50 FDA-approved nanoparticle formulations. Less than 10 were based on metallic nanoparticles. This is a problem because many of these nanoparticle therapeutics demonstrate potent cell killing ability and labeling of cells. A solution to this problem may be the use of weakly coordinated, monovalent metal complexes, which require only one electron to reduce them to their metallic state. Further, by designing nanoparticle syntheses around these monovalent complexes, we can employ weaker, environmentally friendly stabilizers. This strategy also forgoes the use of exogenous reducing agents, because the monovalent complexes can be reduced and stabilized by one reagent. Herein we investigate the use of Au(Me2S)Cl, [Cu(MeCN)4]BF4, and AgBF4 with green stabilizers to synthesize a variety of nanomaterials. We find that a range of sizes of spherical particles, as well as a range of sizes of gold triangular prisms can be synthesized by using techniques that follow this strategy.
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Luska, Kylie. "The catalytic application of ionic liquid-stabilized metal nanoparticles and molecular complexes." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110575.

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Ionic liquids (ILs) have gained considerable research attention as potential replacements for volatile organic chemicals (VOCs) based solvents due to their low vapour pressures and ability to be easily recovered and recycled. Research on ILs has revealed such novel properties as: high chemical and thermal stabilities, good gas solubilites, wide windows of electrochemical stability, good electrical conductivities, high ionic mobilities and immiscibilities with some organic solvents and water. The exploitation of these IL properties has expanded the application scope to include: analytics, catalysis, electrochemistry, nanotechnology, synthesis and separations. This thesis examined the use of ILs in the synthesis of metal nanoparticles (NPs) and molecular complexes, with their application in biphasic catalysis. Metal NPs were synthesized directly in imidazolium or phosphonium ILs, which act as a reaction solvent and an electrostatic NP stabilizer. ILs functionalized with a metal binding moiety (i.e. thiolate or phosphine), otherwise known as functionalized ILs (FILs), were also employed for the synthesis of NPs to enhance their stability by direct attachment of the IL moiety to the metal surface. Transition metal NPs embedded in an IL solvent provided highly effective and recyclable biphasic hydrogenation catalysts for the reduction of alkene and arene substrates. FILs were also employed as stabilizing species of molecular complexes used as biphasic hydroformylation catalysts of long-chain olefins. Important to all of these studies was the influence of the IL parameters (i.e. cationic headgroup, alkyl chain length, counter anion) on the properties of the metal NPs and molecular complexes (i.e. NP size, surface plasmon band, stability under catalytic conditions, catalytic activity and selectivity). ILs are shown to be a highly tunable class of compounds, which allow for control of the properties of metal species stabilized within an IL.
Les liquides ioniques (LIs) ont fait l'objet d'une attention considérable en tant qu'alternatives potentielles aux solvants à base de composés organiques volatiles du fait de leur faible pression de vapeur saturante et de la facilité avec laquelle on peut les récupérer et les recycler. La recherche sur les LIs a par ailleurs révélé de nombreuses propriétés telles que : une grande stabilité chimique et thermique, de bonnes solubilités pour les gaz, une large fenêtre de stabilité électrochimique, une bonne conductivité électrique, une bonne mobilité ionique et une immiscibilité avec certains solvants organiques et l'eau. L'exploitation de ces propriétés ont étendues le champ des applications pour comprendre : la chimie analytique, la catalyse, l'électrochimie, la nanotechnologie, la synthèse et la purification. Cette thèse traite de l'utilisation des LIs pour la synthèse de nanoparticules (NPs) métalliques et de complexes, ainsi que de leur utilisation en catalyse biphasique. Des NPs métalliques ont été synthétisées directement dans les LIs à base de cations imidazolium ou phosphonium. Ces LIs jouent le rôle de solvant et de stabilisants électrostatiques pour les NPs. Des LIs fonctionnalisés avec une espèce ligante (i.e. un thiolate ou une phosphine), appelés LIs fonctionnalisés (LIFs), ont été employés pour la synthèse de NPs pour améliorer leur stabilité par attachement direct du LI à la surface métallique. Les NPs de métaux de transition ainsi obtenues sont très actives en catalyse biphasique d'hydrogénation des alcènes et des arènes et recyclables. Les LIFs ont également été employés comme ligands pour des complexes moléculaires utilisés en catalyse biphasique d'hydroformylation des oléfines à longue chaine. Au centre de cette étude, les paramètres moléculaires des LIs (i.e. le groupement cationique, la longueur de la chaine alkyle, le contre-ion) se sont révélés influer sur les propriétés des NPs métalliques et des complexes moléculaires (i.e. la taille des NPs, leur bande plasmon, leur stabilité en condition catalytique, leur activité catalytique et leur sélectivité). Les LIs constituent une classe de composés hautement versatiles, qui permettent le contrôle des propriétés des espèces métalliques qu'ils stabilisent.
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Rogers, Nicola Jane. "The development of gold nanoparticles labelled with transition metal complexes for imaging applications." Thesis, University of Birmingham, 2014. http://etheses.bham.ac.uk//id/eprint/5058/.

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13 nm and 100 nm citrate-stabilised gold nanoparticles are used as inert scaffolds for the assembly of multiple transition metal lumiphores, and thiol-appended ruthenium(II) and iridium(III) polypyridyl complexes have been synthesised for surface-attachment. The direct attachment of cationic lumiphores to citrate-stabilised gold colloids with negative zeta potentials, affords nanoparticle aggregation, due to loss of electrostatic stabilisation. In order to circumvent this problem, a surfactant pre-coating step has been implemented, and the following commercial surfactants have been evaluated: Triton™ X-100, TWEEN® 20, and Zonyl® 7950. Gold nanoparticles coated with Zonyl® 7950 fluorosurfactant can be functionalised with cationic lumiphores and colloidal stability is maintained even at high nanoparticle concentrations, i.e. 9 nM. The fluorosurfactant not only ensures colloidal stability, but also enhances the emission of the ruthenium(II) and iridium(III) complexes investigated. Importantly, the complexes attached on the resultant luminescent nanoprobes do not exhibit luminescence quenching from the gold nanoparticles. Imaging applications of the resultant luminescent nanoparticles have been demonstrated in in vitro cellular uptake studies and in blood flow particle tracking within the microvasculature. Furthermore, gold nanoparticles have been co-coated with lumiphores and both functional peptides, for targeted delivery in cells, and gadolinium(III) complexes, in order to realise imaging probes for both luminescence and MRI detection.
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Yakushev, I. A., N. Y. Kozitsyna, O. N. Kondratyeva, M. N. Vargaftik, and I. I. Moiseev. "Mixed-Metal Palladium(II) Complexes: a Way from Heterometallic Carboxylates to Bimetallic Nanoparticles." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35239.

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The paper describes some chemical transformations of the mixed-metal palladium (II) complexes, including interactions of binuclear complexes with pyridine, 1,10-phenanthroline and bipyridine; also described thermal and reductive transformations of some binuclear and pentanuclear nitrogen-containing complexes, in particular red-ox transformations in reductive media to yield mixed-metal nanomaterials. For this nanomaterials and nanoalloys also provided HREM and TEM investigations. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35239
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Thangwane, Selaelo Christabel. "Synthesis and characterization of substituted dithiocarbamates ligands and complexes as a source of metal (Pb, Ni & Co) sulphide nanoparticles." Thesis, Vaal University of Technology, 2017. http://hdl.handle.net/10352/396.

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M. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology.
Lead, nickel and cobalt dithiocarbamates complexes were synthesized using methanol and water as solvents. All complexes were refluxed at 60 °C, cooled at room temperature, washed with methanol to remove the impurities and dried under the fume hood. A combination of Fourier transformer infrared (FTIR), elemental analysis (EA) and thermogravimetric analysis (TGA) were used to characterize these complexes. There was shifting of bands from low to high frequencies of the dithiocarbamates complexes compared to benzimidazole derivatives. The absence of the N-H band and the presence of new C=S bands confirmed that the complexes can be used in the preparation of metal sulphide nanoparticles. Elemental analysis showed that there was a percentage mismatch for the complexes I, III, IV and V. Complexes II and VI calculated percentages were within the limits with the found percentages except for sulphur which was low. The TGA curves decomposed to form a mixture of metal and metal sulphides for complex I, II, III and IV except for complex VI which gave metal sulphide only. All benzimidazole complexes decomposed at higher temperatures and were considered as stable complexes. Lead sulphide (PbS) is an important group IV-VI metal chalcogenide semiconductor. It has a direct narrow band gap of 0.41 eV at 300K and a large excitonic Bohr radius of 18 nm. Lead sulphide absorption band can be tuned to anywhere between near IR to UV (0.4μm) covering the entire visible spectrum, while achieving the quantum confinement region. The synthesis of lead sulphide nanoparticles was conducted by varying the effect of the reaction conditions such as the type of capping agents and temperature. Lead dithiocarbamate complex derived from benzimidazole, [Pb(S2N2C8H5)2] was thermolysed in hexadecylamine (HDA) and trioctylphosphine oxide (TOPO) at different reaction temperatures (140, 160 and 180 °C) to produce HDA and TOPO capped PbS nanoparticles. The nanoparticles were characterized using X-ray diffraction (XRD) for structural analysis, transmission electron microscopy (TEM) for shape and size, Ultraviolet visible (UV/Vis) and Photoluminescence (PL) spectroscopy for optical properties. An increase in temperature gave a decrease in the sizes of the nanoparticles when using the HDA capped lead benzimidazole dithiocarbamate complex. The observed morphology was cubes. TOPO capped lead benzimidazole dithiocarbamate complex gave no specific trend when temperature was varied. A cross-like layer with quasi spherical particles on top was observed at 160 °C. At 180 °C, the cross-like layer decomposed into rods- like materials with quasi spherical particles on top for TOPO capped PbS nanoparticles. For lead 2-methylbenzimidazole [Pb(S2N2C9H7)2] dithiocarbamate complex, TOPO capped PbS produced agglomerated cubic morphology at low temperature but as the temperature was increased agglomerated cylindrical shapes were observed. HDA capped PbS produced polydispersed nanocubes which were increasing in size when the temperature was increased. Nanoparticles displayed a blue shift in band edges with good photoluminescence behaviour which was red shifted from their respective band edges all temperatures and capping agents. XRD confirmed the crystal structure of cubic phase (galena) of PbS at all temperatures except for HDA capped PbS nanoparticles at 140 °C from lead benzimidazole dithiocarbamate complex which confirmed the crystal structure of face-centred cubic phase of PbS nanoparticles. Nickel sulphide has much more complicated phase diagram than cobalt sulfides and iron sulfides. Their chemical composition has many crystalline phases such as α-NiS, β=NiS, NiS2, Ni3S2, Ni3S4, Ni7S6 and Ni9S8. Ni3S2 phase has shown potential as a low-cost counter electrode material in dye sensitised solar cells, while the α-NiS phase has been applied as a cathode Material in lithium-ion batteries. The synthesis of nickel sulphide nanoparticles was done by varying the effect of the reaction conditions such concentration and temperature. Nickel benzimidazole dithiocarbamate [Ni(S2N2C8H5)2] and nickel 2-methylbenzimidazole [Ni (S2N2C9H7)2] dithiocarbamates complexes were thermolysed in hexadecylamine (HDA) at different reaction temperatures (140, 160 and 180 °C) and precursor concentrations (0.30, 0.35 and 0.40 g) to produce HDA capped NiS nanoparticles. It was observed that increasing both temperature and precursor concentration increased the size of the nanoparticles. Anisotropic particles were observed for both complexes when varying precursor concentration and temperature. Nickel benzimidazole dithiocarbamate complex produced stable shapes (spheres and cubes) of nickel sulphide nanoparticles. Nickel 2-methylbenzimidazole dithiocarbamate complex produced a mixture of spheres, cubes, triangles and rods nickel sulphide nanoparticles at all concentrations. But when varying temperature, it only produced that mixture at 160 °C. The optical measurements supported the presence of smaller particles at all temperatures and concentrations. XRD showed the presence of C7OS8 and pure nickel as impurities. However, the crystal structure of cubic Ni3S4 was observed at low temperatures and an introduction of monoclinic NixS6 at high temperature (180 °C) when varying temperature for both complexes. When varying concentration using nickel benzimidazole dithiocarbamate complex, XRD showed the presence of NiSO4.6H2O impurities at high temperatures. At 160 °C a mixture of hexagonal NiS and cubic Ni3S4 was observed. At low temperatures only nickel as a metal was found as an impurity and the crystal structure of cubic Ni3S4 was observed. When nickel 2-methylbenzimidazole complex was used, C7OS8 and pure nickel were found as impurities but the crystal structure of cubic Ni3S4 was observed. Cobalt sulphide (CoS) belongs to the family of group II-IV compounds with considerable potential for application in electronic devices. They have a complex phase diagram and their chemical composition have many phases such as Co4S3, Co9S8, CoS, Co1-xS, Co3S4, Co2S3 and CoS2. The synthesis of cobalt sulphide nanoparticles was conducted by varying the effect of temperature on size and shape of the nanoparticles. Nickel benzimidazole dithiocarbamate, [Ni(S2N2C8H5)2] and nickel 2-methylbenzimidazole [Ni(S2N2C9H7)2] complexes were thermolysed in hexadecylamine (HDA) at different reaction temperatures (140, 160 and 180 °C) to produce HDA capped CoS nanoparticles. Cobalt benzimidazole dithiocarbamate complex produced close to spherical shapes nanoparticles at all temperatures. The images showed that as temperature was increased, the size of the particles decreased. All the main reflection peaks were indexed to face-centred cubic Co3S4 and there were some impurities of C7OS8 at all temperatures. The optical measurements supported the presence of smaller particles at all temperatures. Cobalt 2-methylbenzimidazole dithiocarbamate complex produced big and undefined morphology. The optical properties were also featureless and XRD only showed impurities of C7OS8. The impurity is thought to be generated from a side reaction between benzimidazole and carbon disulphide to give this persistent organic moiety.
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Roffey, A. R. "Dithiocarbamate complexes as single source precursors to metal sulfide nanoparticles for applications in catalysis." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1437012/.

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Herein we report the solvothermal decomposition of a range of metal dithiocarbamate complexes for the synthesis of metal sulfide nanoparticles. Metal sulfides exist in a variety of structural phases, some of which are known to be catalytically active towards various processes. The aim of this work was to synthesise a variety of different metal sulfide phases for future catalysis testing, particularly the iron sulfide greigite (Fe3S4, a thiospinel containing Fe2+ and Fe3+) which is to be tested for CO2 reduction. A range of metal dithiocarbamate complexes were synthesised and Chapter 2 focusses on the synthesis of iron dithiocarbamates. Both iron(II) and iron(III) complexes were synthesised, the latter being a facile, open bench reaction producing a range of [Fe(S2CNRR’)3] complexes. Iron(II) bis(dithiocarbamates) are extremely air sensitive therefore carbonyl protected [Fe(S2CNRR’)2(CO)2] complexes were prepared for ease of use as precursors. The stability of the complexes was tested by TGA to ensure they were suitable precursors for metal sulfide synthesis, i.e. that the carbonyl ligands were sufficiently labile to leave the complexes before decomposition, which proved to be successful. In the following Chapter these iron dithiocarbamate complexes were solvothermally decomposed, but interestingly a combination of iron(II) and iron(III) precursors did not produce greigite as expected, but pyrrhotite (Fe7S8, containing only Fe2+). Systematic studies into the effect of decomposition temperature, precursor concentration and precursor type, on the phase and morphology of the resulting iron sulfide nanoparticles were performed on the iron(III) dithiocarbamate precursor. The phase was found to be highly dependent on both concentration and temperature. The use of a redox active additive, thiuram disulfide, on the decomposition was also investigated and found to have a significant effect, promoting the formation of the metastable greigite phase. Chapter 4 examines the nickel bis(dithiocarbamate) decomposition system to see if its behaviour was consistent with trends observed in the iron case. In general, similar trends were observed in the phase and morphology of the nickel sulfides when the decomposition parameters were varied, metastable phases were observed at lower temperature and higher concentration. The effect of thiuram disulfide on the system was greater, however, than in the iron case, whereby an additional nickel sulfide phase (NiS2) was observed at high concentration in the presence of this additive. Chapter 5 deals with a broader range of metal dithiocarbamate systems, to attempt to elucidate whether or not the trends seen for nickel and iron are universal for metal dithiocarbamate precursors. The Co, Cu, Zn and In dithiocarbamate systems were examined with and without thiuram disulfide, and some effect were seen on the phase of metal sulfide nanoparticle formed, but only at high concentration in the presence of the additive. Mixed-metal studies were performed to investigate the suitability of metal dithiocarbamates as precursors to ternary metal sulfides, and success was observed for iron-nickel, cobalt-nickel and iron-copper sulfides, though the iron-zinc and iron-indium systems only produced binary sulfides. The final Chapter looks into the metal dithiocarbamate decomposition mechanism in detail, using [Ni(S2CNiBu2)2] as a model system. NMR, in situ UV-vis, MS and powder XRD are all employed to probe the mechanism, in conjunction with XAS and computer modelling which was performed by others. The mechanism was found to rely heavily on an intermediate formed from amide exchange between the dithiocarbamate backbone and solvent amine, indicating the solvent plays an extremely significant role in the solvothermal synthesis of metal sulfides from dithiocarbamate precursors.
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Tilbury, Rhys David. "Investigation into Electronic Interactions Between Tetrazolato Complexes and Metal Nanoparticles Synthesised via Laser Ablation." Thesis, Curtin University, 2017. http://hdl.handle.net/20.500.11937/57109.

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Metal nanoparticles were generated by the Laser Ablation Synthesis in Solution approach, encapsulated and stabilised by a variety of ligands in solution. The encapsulation ligands were designed and synthesised to allow the attachment of phosphorescent transition metal complexes on their outer shell. This should facilitate energy transfer between the complex-centre excited state and the surface plasmon resonance of the core. This exploitation of the electronic structure of the nanoparticle surface has insinuations for a variety of photovoltaic applications.
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Zalich, Michael Andrew. "Physical Properties of Magnetic Macromolecule-Metal and Macromolecule-Metal Oxide Nanoparticle Complexes." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/27528.

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Magnetic nanoparticles are of considerable interest owing to their potential applications in biotechnology and the magnetic recording industry. Iron oxides have received much attention owing to their oxidative stability and biocompatibility; however, other transition metals and their alloys are also under investigation. Cobalt has one of the largest magnetic susceptibilities of these materials, but it readily oxidizes upon exposure to air resulting in antiferromagnetic oxide. Hence, coating cobalt nanoparticles with an oxygen-impermeable sheath would confer numerous benefits. Cobalt nanoparticles were prepared by the thermolysis of dicobalt octacarbonyl in two block copolymer micellar systems, wherein the copolymers were precursors to graphite or silica. Subsequent heat treatment of the samples at 600-700oC was conducted to condense the polymer coating around the cobalt nanoparticles and form oxygen impervious graphite or silica sheaths. Magnetic and structural characterization of these novel materials afforded pertinent information about their physical properties. Magnetic susceptometry indicated that the graphite coated cobalt nanoparticles resisted oxidation for over one year. The silica coated cobalt nanoparticles had high saturated specific magnetic moments, but the coatings were brittle and grinding the particles resulted in oxidation over time. Transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and energy-filtered TEM (EFTEM) were employed to study particle size and structural differences of the cobalt nanoparticles before and after heat treatment. The mean particle size and size distribution increased for the graphite coated cobalt particles, due to particle sintering at 700oC. In the silica coated cobalt nanoparticle system, the mean particle size increased when the sample was heat-treated at 600oC leading to a bimodal distribution. This bimodal distribution was explained by a fraction of the particles sintering, while others remained discrete. When the silica system was heat treated at 700oC, the particle size and size distribution remained similar to those of the pre-heat-treated sample, indicating that no sintering had taken place. The rapid pyrolysis of the polymer at 700oC may serve to lock the cobalt nanoparticles into a silica matrix, thus preventing them from coming into contact with one another and sintering. Several diffraction techniques (selected area electron diffraction (SAD), nano-beam electron diffraction (NBD) and x-ray diffraction (XRD)) were used to probe the crystal structure of graphite and silica coated cobalt nanoparticles, which was determined to be predominantly face-centered cubic. Anisotropic magnetic nanoparticles (nanorods) have an increased magnetophoretic mobility over spherical magnetic nanoparticles with the same equatorial radius. This property makes them attractive candidates for in vivo biological applications. Anisotropic mixed ferrite nanoparticles were coated with a biocompatible hydrophilic block copolymer to render them dispersible in aqueous media. Polymer coated mixed ferrite particles exhibited magnetic properties similar to that of pure magnetite, as the total level of other transition metals in the nanoparticulate system was less than 5%. Electron energy loss spectroscopy (EELS) and (EFTEM) confirmed that the dominant elements in the mixed ferrite nanoparticles were iron and oxygen. Furthermore, HRTEM, SAD and XRD analyses indicated that the crystal structure for the mixed ferrite nanoparticles was inverse spinel. X-ray diffraction peaks at low angles for the coated mixed ferrite rods corresponded to poly(ethylene oxide) peaks, suggesting that the block copolymer employed as a dispersant was associated with the particles.
Ph. D.
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Eriksson, Kristofer. "Development and Applications of Surface-Confined Transition Metal Complexes : Heterogeneous Catalysis and Anisotropic Particle Surfaces." Doctoral thesis, Stockholms universitet, Institutionen för organisk kemi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-88215.

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The main focus of this thesis has been directed towards developing novel surface-confined transition metal complexes for applications in heterogeneous catalysis and for the preparation of anisotropic particle surfaces. The first part describes the heterogenization of a homogeneous transition metal-based catalyst tetraphenyl cobalt porphyrin (CoTPP) on silicon wafers and on silica particles. The activity in hydroquinone oxidation for the silica particle-immobilized CoTPPs was found to be increased 100-fold compared to its homogeneous congener whereas the silicon wafer-immobilized CoTPPs achieved lower activity due to the formation of clusters of catalyst molecules on the support surface as detected with atomic force microscopy (AFM). The second part of this thesis describes the development and characterization of anisotropic particle-surfaces by electrochemical site-specific oxidation of surface-confined thiols. Reactive patches or gold gradients could be obtained on the particle surfaces depending on the type of working electrode used and on the electrolyte composition. The particle surface functionalities were characterized with X-ray photoelectron spectroscopy (XPS) and the particle-surface-confined patches and gradients were conjugated with proteins to obtain fluorescence for investigation using fluorescence microscopy. Gold-functionalized siliceous mesocellular foams were further demonstrated to be highly efficient and selective catalysts in the cycloisomerization of 4-alkynoic acids to lactones. The final part of this thesis describes the preparation and characterization of palladium nanoparticles heterogenized in the pores of siliceous mesocellular foam. The nanoparticles were analyzed with transmission electron microscopy (TEM) and found to have a size of 1-2 nm. Primary- and secondary benzylic- and allylic alcohols were oxidized by the heterogeneous palladium nanoparticles in high to excellent yields using air atmosphere as the oxygen source. The nanopalladium catalyst was used up to five times without any decrease in activity and the size of the nanoparticles was retained according to TEM.

At the time of doctoral defence the following paper were unpublished and had a status as follows: Paper1: Manuscript; Paper 4: Manuscript

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Books on the topic "Metal complexes and nanoparticles"

1

Thota, Sreekanth, and Debbie C. Crans. Metal Nanoparticles. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2018. http://dx.doi.org/10.1002/9783527807093.

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Capek, Ignác. Noble Metal Nanoparticles. Tokyo: Springer Japan, 2017. http://dx.doi.org/10.1007/978-4-431-56556-7.

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Kanchi, Suvardhan, and Shakeel Ahmed, eds. Green Metal Nanoparticles. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2018. http://dx.doi.org/10.1002/9781119418900.

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4

Tomasik, Piotr. Pyridine-metal complexes. New York: Wiley, 1985.

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Hartley, F. R. Supported Metal Complexes. Dordrecht: Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-5247-8.

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Voloshin, Yan, Irina Belaya, and Roland Krämer. Cage Metal Complexes. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-56420-3.

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Ciardelli, F., E. Tsuchida, and D. Wöhrle, eds. Macromolecule-Metal Complexes. Berlin, Heidelberg: Springer Berlin Heidelberg, 1996. http://dx.doi.org/10.1007/978-3-642-60986-2.

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Tomasik, Piotr. Pyridine-metal complexes. New York: Wiley, 1985.

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Tomasik, Piotr. Pyridine-metal complexes. Edited by Ratajewicz Zbigniew, Newkome George R, and Strekowski Lucjan. New York: Wiley, 1985.

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Tomasik, Piotr. Pyridine-metal complexes. Edited by Ratajewicz Zbigniew, Newkome George R, and Strekowski Lucjan. New York: Wiley, 1985.

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Book chapters on the topic "Metal complexes and nanoparticles"

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Sau, Tapan K., and Andrey L. Rogach. "Colloidal Synthesis of Noble Metal Nanoparticles of Complex Morphologies." In Complex-Shaped Metal Nanoparticles, 7–90. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2012. http://dx.doi.org/10.1002/9783527652570.ch1.

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Herrmann, Anne-Kristin, Nadja C. Bigall, Lehui Lu, and Alexander Eychmüller. "Ordered and Nonordered Porous Superstructures from Metal Nanoparticles." In Complex-Shaped Metal Nanoparticles, 339–59. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2012. http://dx.doi.org/10.1002/9783527652570.ch10.

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Noguez, Cecilia, and Ana L. González. "Localized Surface Plasmons of Multifaceted Metal Nanoparticles." In Complex-Shaped Metal Nanoparticles, 361–93. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2012. http://dx.doi.org/10.1002/9783527652570.ch11.

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Klar, Thomas A., and Jochen Feldmann. "Fluorophore-Metal Nanoparticle Interactions and Their Applications in Biosensing." In Complex-Shaped Metal Nanoparticles, 395–427. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2012. http://dx.doi.org/10.1002/9783527652570.ch12.

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Jäckel, Frank, and Jochen Feldmann. "Surface-Enhanced Raman Scattering Using Complex-Shaped Metal Nanostructures." In Complex-Shaped Metal Nanoparticles, 429–54. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2012. http://dx.doi.org/10.1002/9783527652570.ch13.

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Govorov, Alexander O., Zhiyuan Fan, and Alexander B. Neiman. "Photothermal Effect of Plasmonic Nanoparticles and Related Bioapplications." In Complex-Shaped Metal Nanoparticles, 455–75. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2012. http://dx.doi.org/10.1002/9783527652570.ch14.

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Soh, Jun Hui, and Zhiqiang Gao. "Metal Nanoparticles in Biomedical Applications." In Complex-Shaped Metal Nanoparticles, 477–519. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2012. http://dx.doi.org/10.1002/9783527652570.ch15.

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Mai, Nguyen T., Derrick Mott, and Shinya Maenosono. "Anisotropic Nanoparticles for Efficient Thermoelectric Devices." In Complex-Shaped Metal Nanoparticles, 521–43. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2012. http://dx.doi.org/10.1002/9783527652570.ch16.

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Cui, Chun-Hua, and Shu-Hong Yu. "Controlling Morphology in Noble Metal Nanoparticles via Templating Approach." In Complex-Shaped Metal Nanoparticles, 91–116. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2012. http://dx.doi.org/10.1002/9783527652570.ch2.

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Tian, Na, Yu-Hua Wen, Zhi-You Zhou, and Shi-Gang Sun. "Shape-Controlled Synthesis of Metal Nanoparticles of High Surface Energy and Their Applications in Electrocatalysis." In Complex-Shaped Metal Nanoparticles, 117–65. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2012. http://dx.doi.org/10.1002/9783527652570.ch3.

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Conference papers on the topic "Metal complexes and nanoparticles"

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Bhanjana, Gaurav, Neeraj Kumar, Rajesh Thakur, Neeraj Dilbaghi, Sandeep Kumar, S. K. Tripathi, Keya Dharamvir, Ranjan Kumar, and G. S. S. Saini. "Antimicrobial Activity of Metal & Metal Oxide Nanoparticles Interfaced With Ligand Complexes Of 8-Hydroxyquinoline And α-Amino Acids." In INTERNATIONAL CONFERENCE ON ADVANCES IN CONDENSED AND NANO MATERIALS (ICACNM-2011). AIP, 2011. http://dx.doi.org/10.1063/1.3653665.

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Walton, Finlay, Song Tang, Weizhen Li, and Steven L. Neale. "Patterning ultrafine metal nanoparticles using optoelectronic tweezers (OET)." In Complex Light and Optical Forces XIV, edited by David L. Andrews, Enrique J. Galvez, and Halina Rubinsztein-Dunlop. SPIE, 2020. http://dx.doi.org/10.1117/12.2546214.

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Zimmermann, Kristen A., Jianfei Zhang, Harry Dorn, Christopher Rylander, and Marissa Nichole Rylander. "Synthesis and Cytotoxicity Analysis of Carbon Nanohorn-Quantum Dot Complexes." In ASME 2011 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2011. http://dx.doi.org/10.1115/sbc2011-53968.

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Carbon nanoparticles have the potential to significantly impact the medical field over the next decade. Currently, carbon nanoparticles are being studied for a myriad of applications, including drug delivery, selective laser therapy, imaging, and biosensing. The most common type of carbon particles being investigated are carbon nanotubes (CNTs). CNTs are attractive materials for medical applications because of their physical properties and the ease with which they can be surface modified; however, there is a great deal of controversy over their possible toxicity. A more novel type of CNT that was discovered in 1999 by Iijima et al. is the carbon nanohorn [1]. Individual single-walled nanohorns (SWNHs) are single graphene sheets that roll into a conical open ended structure. The open ends of these cones are then attracted to one another through van der Waals interactions and form a flower-like final structure [2]. SWNHs are more favorable for medical applications because they are produced without the use of metal catalysts abating the concern of toxicity associated with CNTs.
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Sun, Greg, and Jacob B. Khurgin. "Coupled Mode Theory of Field Enhancement in Complex Metal Nanoparticles." In Quantum Electronics and Laser Science Conference. Washington, D.C.: OSA, 2011. http://dx.doi.org/10.1364/qels.2011.qtuh5.

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Avramenko, Valentin, Vitaly Mayorov, Dmitry Marinin, Alexander Mironenko, Marina Palamarchuk, and Valentin Sergienko. "Macroporous Catalysts for Hydrothermal Oxidation of Metallorganic Complexes at Liquid Radioactive Waste Treatment." In ASME 2010 13th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2010. http://dx.doi.org/10.1115/icem2010-40186.

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One of the main problems of liquid radioactive waste (LRW) management is concerned with treatment of decontamination waters containing organic ligands. The organic ligands like oxalic, citric and ethylenediaminetetraacetic acids form stable complexes with radionuclides which puts restrictions on application of many technologies of LRW management. One of the ways of destruction of metallorganic complexes consists in using the catalytic oxidation. However, the heterophase catalytic oxidation is rather problematic due to formation of metal oxides on the catalyst surface and calmatation of meso- and micropores. A possible solution of the above problem can be found in synthesis of macroporous catalysts for oxidation having a regular macroporous structure. The present paper describes the template synthesis of macroporous metalloxide catalysts performed with using siloxane-acrylate microemulsions as templates. The method for impregnation of precious metals (PM) particles into the template, which enables one to produce PM nanoparticles of a specific size and immobilize them in the porous structure of the synthesized metalloxide catalysts, is presented. A possible mechanism of the synthesis of macroporous catalysts is suggested and the comparison of the electronic and photon-correlation spectroscopy results obtained at different stages of catalysts synthesis was conducted.
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Myneni, Satish, Sara Thomas, and Bhoopesh Mishra. "Microbe-Metal Interactions: Novel High Energy-Resolution XANES Spectroscopy of Zn and Hg Complexes and Nanoparticles at Bacteria-Water Interfaces." In Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.1877.

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Wu, Ye, Jian Xu, and Ruyan Guo. "Achieving near-infrared deep tissue imaging via metal organic complex nanoparticles." In Photonic Fiber and Crystal Devices: Advances in Materials and Innovations in Device Applications XIII, edited by Shizhuo Yin and Ruyan Guo. SPIE, 2019. http://dx.doi.org/10.1117/12.2534826.

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Leeladhar, Rajesh, Wei Xu, and Chang-Hwan Choi. "Effects of Nanofluids on Droplet Evaporation and Wetting on Nanoporous Superhydrophobic Surfaces." In ASME 2009 Second International Conference on Micro/Nanoscale Heat and Mass Transfer. ASMEDC, 2009. http://dx.doi.org/10.1115/mnhmt2009-18551.

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In this paper, nanofluid droplets (fluid containing metal nanoparticles) were subjected to evaporation on a nanoporous superhydrophobic surface to study the effects of nanoparticles on evaporation kinetics, wetting dynamics, and dry-out patterns. Metal nanoparticles (gold chloride) of three different sizes (10, 100, and 250 nm) at three different concentrations (0.001, 0.01, and 0.1% wt) were tested as nanofluids, uniformly dispersed in deionized water. Anodized alumina membranes (200 nm in pore diameter) were tested as nanoporous superhydrophobic surfaces, coated with a self assembled monolayer (SAM). During the course of evaporation in a room condition, the change of a contact angle, contact diameter, height, and volume was measured by a goniometer and compared with that of the base fluid (water) taken as a control. The initial equilibrium contact angle of the nanofluids was significantly affected by the nanoparticle sizes and concentrations. During evaporation, the evaporation behavior for the nanofluids exhibited a complete different mode from that of the base fluid. In terms of a contact angle, nanofluids showed slower decrease rate than base fluid. Nanofluid contact diameter remained almost a constant throughout evaporation with a slight change only at the very end of evaporation stage, whereas the base fluid showed a sequence of constant, increase, and mixed states of increase/decrease behavior. The nanofluids also showed a clear distinction in the evaporation rates, resulting in slower rate than base fluid. The variation of the nanoparticle sizes and concentrations did not make significant difference in the evaporation rate within the tested conditions. No abrupt change in a contact angle and diameter was observed during the evaporation, suggesting that no remarkable wetting transition from Cassie (de-wetting) to Wenzel (wetting) state occurred. The scanning electron microscope (SEM) images of the deposited nanoparticles after complete evaporation of solvent showed unique dry-out patterns depending on nanoparticle sizes and concentrations, e.g., a thick ring-like pattern with larger particle sizes while a uniformly distributed pattern with smaller particles at higher concentrations.
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Jo, Byeongnam, Seunghwan Jung, Donghyun Shin, and Debjyoti Banerjee. "Anomalous Rheological Behavior of Complex Fluids (Nanofluids)." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-64091.

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The rheological behavior of various complex fluids was explored in this experimental study. Nanofluids were obtained by mixing nanoparticles with various solvents. The solvents consisted of metal salt eutectics that melt at high temperatures (exceeding 200 °C) depending on the composition of the metal salts in the eutectics. The rheological behaviors of these high temperature solvents were measured as a function of temperature before and after mixing with different types of nanoparticles (chemical composition, size, shape and concentration). These nanofluids exhibited non-Newtonian behavior (shear thinning behavior) while some of the other nanofluids were surprisingly found to have Newtonian behavior. It was observed that high aspect ratio nanoparticles (e.g., stick shaped carbon nanotubes) were more likely to cause shear thinning behavior of the resulting nanofluids.
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Tavakoli, Mahmoud, Mohammad H. Malakooti, Hugo Paisana, Yunsik Ohm, Daniel Green Marques, Pedro Alhais Lopes, Ana P. Piedade, Anibal T. de Almeida, and Carmel Majidi. "Fabrication of Soft and Stretchable Electronics Through Integration of Printed Silver Nanoparticles and Liquid Metal Alloy." In ASME 2018 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/smasis2018-8007.

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Liquid metal (LM) alloys such as eutectic gallium indium (EGaIn) and gallium-indium-tin (Galinstan) have been used in the fabrication of soft and stretchable electronics during the past several years. The liquid-phase and high electrical conductivity of these materials make them one of the best candidates for fabrication of deformable electronics and multifunctional material systems. While liquid metals are highly reliable for fabrication of simple circuits and stretchable microfluidic devices, their application for producing complex circuits faces fabrication challenges due to their high surface tension and surface oxidization. In this study, we propose a scalable, cost-effective, and versatile technique to print complex circuits using silver nanoparticles and transform them into stretchable electronics by incorporating eutectic gallium indium alloys to the circuit. As a result, the deposited liquid metal considerably increases the electrical conductivity and stretchability of the fabricated electronics. The reliability and performance of these stretchable conductors are demonstrated by studying their electromechanical behavior and integrating them into skin-like electronics, termed electronic tattoos.
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Reports on the topic "Metal complexes and nanoparticles"

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Choudhary, Ruplal, Victor Rodov, Punit Kohli, Elena Poverenov, John Haddock, and Moshe Shemesh. Antimicrobial functionalized nanoparticles for enhancing food safety and quality. United States Department of Agriculture, January 2013. http://dx.doi.org/10.32747/2013.7598156.bard.

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Original objectives The general goal of the project was to utilize the bactericidal potential of curcumin- functionalizednanostructures (CFN) for reinforcement of food safety by developing active antimicrobial food-contact surfaces. In order to reach the goal, the following secondary tasks were pursued: (a) further enhancement of the CFN activity based on understanding their mode of action; (b) preparing efficient antimicrobial surfaces, investigating and optimizing their performance; (c) testing the efficacy of the antimicrobial surfaces in real food trials. Background to the topic The project dealt with reducing microbial food spoilage and safety hazards. Cross-contamination through food-contact surfaces is one of the major safety concerns, aggravated by bacterial biofilm formation. The project implemented nanotech methods to develop novel antimicrobial food-contact materials based on natural compounds. Food-grade phenylpropanoidcurcumin was chosen as the most promising active principle for this research. Major conclusions, solutions, achievements In agreement with the original plan, the following research tasks were performed. Optimization of particles structure and composition. Three types of curcumin-functionalizednanostructures were developed and tested: liposome-type polydiacetylenenanovesicles, surface- stabilized nanoparticles and methyl-β-cyclodextrin inclusion complexes (MBCD). The three types had similar minimal inhibitory concentration but different mode of action. Nanovesicles and inclusion complexes were bactericidal while the nanoparticlesbacteriostatic. The difference might be due to different paths of curcumin penetration into bacterial cell. Enhancing the antimicrobial efficacy of CFN by photosensitization. Light exposure strengthened the bactericidal efficacy of curcumin-MBCD inclusion complexes approximately three-fold and enhanced the bacterial death on curcumin-coated plastic surfaces. Investigating the mode of action of CFN. Toxicoproteomic study revealed oxidative stress in curcumin-treated cells of E. coli. In the dark, this effect was alleviated by cellular adaptive responses. Under light, the enhanced ROS burst overrode the cellular adaptive mechanisms, disrupted the iron metabolism and synthesis of Fe-S clusters, eventually leading to cell death. Developing industrially-feasible methods of binding CFN to food-contact surfaces. CFN binding methods were developed for various substrates: covalent binding (binding nanovesicles to glass, plastic and metal), sonochemical impregnation (binding nanoparticles to plastics) and electrostatic layer-by-layer coating (binding inclusion complexes to glass and plastics). Investigating the performance of CFN-coated surfaces. Flexible and rigid plastic materials and glass coated with CFN demonstrated bactericidal activity towards Gram-negative (E. coli) and Gram-positive (Bac. cereus) bacteria. In addition, CFN-impregnated plastic material inhibited bacterial attachment and biofilm development. Testing the efficacy of CFN in food preservation trials. Efficient cold pasteurization of tender coconut water inoculated with E. coli and Listeriamonocytogeneswas performed by circulation through a column filled with CFN-coated glass beads. Combination of curcumin coating with blue light prevented bacterial cross contamination of fresh-cut melons through plastic surfaces contaminated with E. coli or Bac. licheniformis. Furthermore, coating of strawberries with CFN reduced fruit spoilage during simulated transportation extending the shelf life by 2-3 days. Implications, both scientific and agricultural BARD Report - Project4680 Page 2 of 17 Antimicrobial food-contact nanomaterials based on natural active principles will preserve food quality and ensure safety. Understanding mode of antimicrobial action of curcumin will allow enhancing its dark efficacy, e.g. by targeting the microbial cellular adaptation mechanisms.
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2

Chefetz, Benny, Baoshan Xing, Leor Eshed-Williams, Tamara Polubesova, and Jason Unrine. DOM affected behavior of manufactured nanoparticles in soil-plant system. United States Department of Agriculture, January 2016. http://dx.doi.org/10.32747/2016.7604286.bard.

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The overall goal of this project was to elucidate the role of dissolved organic matter (DOM) in soil retention, bioavailability and plant uptake of silver and cerium oxide NPs. The environmental risks of manufactured nanoparticles (NPs) are attracting increasing attention from both industrial and scientific communities. These NPs have shown to be taken-up, translocated and bio- accumulated in plant edible parts. However, very little is known about the behavior of NPs in soil-plant system as affected by dissolved organic matter (DOM). Thus DOM effect on NPs behavior is critical to assessing the environmental fate and risks related to NP exposure. Carbon-based nanomaterials embedded with metal NPs demonstrate a great potential to serve as catalyst and disinfectors. Hence, synthesis of novel carbon-based nanocomposites and testing them in the environmentally relevant conditions (particularly in the DOM presence) is important for their implementation in water purification. Sorption of DOM on Ag-Ag₂S NPs, CeO₂ NPs and synthesized Ag-Fe₃O₄-carbon nanotubebifunctional composite has been studied. High DOM concentration (50mg/L) decreased the adsorptive and catalytic efficiencies of all synthesized NPs. Recyclable Ag-Fe₃O₄-carbon nanotube composite exhibited excellent catalytic and anti-bacterial action, providing complete reduction of common pollutants and inactivating gram-negative and gram-positive bacteria at environmentally relevant DOM concentrations (5-10 mg/L). Our composite material may be suitable for water purification ranging from natural to the industrial waste effluents. We also examined the role of maize (Zeamays L.)-derived root exudates (a form of DOM) and their components on the aggregation and dissolution of CuONPs in the rhizosphere. Root exudates (RE) significantly inhibited the aggregation of CuONPs regardless of ionic strength and electrolyte type. With RE, the critical coagulation concentration of CuONPs in NaCl shifted from 30 to 125 mM and the value in CaCl₂ shifted from 4 to 20 mM. This inhibition was correlated with molecular weight (MW) of RE fractions. Higher MW fraction (> 10 kDa) reduced the aggregation most. RE also significantly promoted the dissolution of CuONPs and lower MW fraction (< 3 kDa) RE mainly contributed to this process. Also, Cu accumulation in plant root tissues was significantly enhanced by RE. This study provides useful insights into the interactions between RE and CuONPs, which is of significance for the safe use of CuONPs-based antimicrobial products in agricultural production. Wheat root exudates (RE) had high reducing ability to convert Ag+ to nAg under light exposure. Photo-induced reduction of Ag+ to nAg in pristine RE was mainly attributed to the 0-3 kDa fraction. Quantification of the silver species change over time suggested that Cl⁻ played an important role in photoconversion of Ag+ to nAg through the formation and redox cycling of photoreactiveAgCl. Potential electron donors for the photoreduction of Ag+ were identified to be reducing sugars and organic acids of low MW. Meanwhile, the stabilization of the formed particles was controlled by both low (0-3 kDa) and high (>3 kDa) MW molecules. This work provides new information for the formation mechanism of metal nanoparticles mediated by RE, which may further our understanding of the biogeochemical cycling and toxicity of heavy metal ions in agricultural and environmental systems. Copper sulfide nanoparticles (CuSNPs) at 1:1 and 1:4 ratios of Cu and S were synthesized, and their respective antifungal efficacy was evaluated against the pathogenic activity of Gibberellafujikuroi(Bakanae disease) in rice (Oryza sativa). In a 2-d in vitro study, CuS decreased G. fujikuroiColony- Forming Units (CFU) compared to controls. In a greenhouse study, treating with CuSNPs at 50 mg/L at the seed stage significantly decreased disease incidence on rice while the commercial Cu-based pesticide Kocide 3000 had no impact on disease. Foliar-applied CuONPs and CuS (1:1) NPs decreased disease incidence by 30.0 and 32.5%, respectively, which outperformed CuS (1:4) NPs (15%) and Kocide 3000 (12.5%). CuS (1:4) NPs also modulated the shoot salicylic acid (SA) and Jasmonic acid (JA) production to enhance the plant defense mechanisms against G. fujikuroiinfection. These results are useful for improving the delivery efficiency of agrichemicals via nano-enabled strategies while minimizing their environmental impact, and advance our understanding of the defense mechanisms triggered by the NPs presence in plants.
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3

White, Carter James. Selenophene transition metal complexes. Office of Scientific and Technical Information (OSTI), July 1994. http://dx.doi.org/10.2172/10190649.

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Cotton, F. A., and S. C. Haefner. Metal-metal multiply bonded complexes of technetium. Final report. Office of Scientific and Technical Information (OSTI), March 1995. http://dx.doi.org/10.2172/434856.

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5

Lawson, Chris M., and Gary M. Gray. New Metal Organic Nonlinear Optical Complexes. Fort Belvoir, VA: Defense Technical Information Center, December 2000. http://dx.doi.org/10.21236/ada391105.

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6

Aikens, Christine M. Structure and Optical Properties of Noble Metal Nanoparticles. Fort Belvoir, VA: Defense Technical Information Center, August 2012. http://dx.doi.org/10.21236/ada575706.

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Aikens, Christine M. Structure and Optical Properties of Noble Metal Nanoparticles. Fort Belvoir, VA: Defense Technical Information Center, August 2012. http://dx.doi.org/10.21236/ada575836.

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8

Sharp, P. R. Late transition metal oxo and imido complexes. Office of Scientific and Technical Information (OSTI), December 1992. http://dx.doi.org/10.2172/7017245.

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Fujita, Etsuko. Photoreduction of CO{sub 2} using metal complexes. Office of Scientific and Technical Information (OSTI), April 1996. http://dx.doi.org/10.2172/211478.

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Crosby, G. A. Investigations of charge-separation processes in metal complexes. Office of Scientific and Technical Information (OSTI), February 1991. http://dx.doi.org/10.2172/5943145.

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