Tesi: "Complex compounds"

1

Malgas, Rehana. "The application of novel multinuclear catalysts derived from dendrimeric ligands in the polymerization and oligomerization of unsaturated hydrocarbons". Thesis, University of the Western Cape, 2007. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_7858_1183727432.

Testo completo

Abstract (sommario):

G1 and G2 dendrimeric salicylaldimine ligands containing both substituted and unsubstituted aryl rings were synthesized via a Schiff base condensation of the appropriate salicylaldehyde and the peripheral amino groups of the corresponding G1 and G2 polypropyleneimine dendrimers. The new ligands were characterized using FTIR, 1H NMR and 13C NMR spectroscopy, elemental analysis and ESI mass spectrometry. The dendrimeric ligands were converted to multinuclear nickel complexes by reaction with nickelacetate. The metal complexes were characterized by FTIR spectroscopy, elemental analysis and ESI mass spectrometry.

Some of the dendritic complexes were evaluated as catalyst precursors in the oligomerization of &alpha
-olefins such as ethylene and 1-pentene, using aluminium alkyls such as EtAlCl2 and modified methylaluminoxane (MMAO) as activators. All the dendrimeric catalysts evaluated are active in the oligomerization reactions. From the oligomerization results it was observed that there is a clear dendritic effect, in that both catalyst activity as well as selectivity are impacted by the dendrimer generation. In most cases it was observed that the second generation complexes show higher activity than the corresponding first generation complexes.

The dendrimeric complexes were also evaluated as catalyst precursors in the vinyl polymerization of norbornene. In this case methylaluminoxane (MAO) were employed as an activator. Once again it was noted that a dendritic effect is operative, with second generation metallodendrimers having a higher activity than the first generation complexes.

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Kean, Suzanna Dawn. "Modified cyclodextrins and their complexes". Title page, contents and abstract only, 1999. http://web4.library.adelaide.edu.au/theses/09PH/09phk243.pdf.

Testo completo

Abstract (sommario):

Addendum page pasted onto front end paper. Copies of author's previously published articles inserted. Includes bibliographical references. Investigates the factors that govern the stability of cyclodextrin inclusion complexes with a range of systematically modified cyclodextrins.

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Pyrka, Gloria Jean. "Electrochemical and structural studies of one-dimensional copper charge transfer complexes". Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184493.

Testo completo

Abstract (sommario):

The electrochemistry of solid electrodes of charge transfer complexes of tetracyanoquinodimethane (TCNQ) and copper complexes with nitrogen containing chelates, such and dipyridylamine (dpaH), bipyridyl (bpy) and 1,10-dimethyl-2,9-phenanthroline (dmp), has been investigated with cyclic voltammetry. Pressed pellet electrodes of these complexes exhibit a broad electrochemically stable region. The oxidative and reductive breakdown reactions involve solid state reactions into the bulk electrode. These materials also act as electron mediators for glucose oxidation in glucose oxidase modified electrodes. The structure of the model compound, copper(I)(dpaH)₂Cl has been determined to have a distorted tetrahedral coordination sphere. The electrochemistry of solid electrodes of charge transfer complexes of tetrathiafulvalene (TTF) with copper chloride and copper bromide has been investigated with cyclic voltammetry. Pressed pellet electrodes do not exhibit a broad stable region, as do the TCNQ complexes. A preliminary structure of the organic part of tetramethyltetraselenafulvalene copper chloride has been determined from the solution of the Patterson function and exhibits a displacive modulation with a repeat unit of seven TMTSF molecules. (TTF)(SCN)₀ͺ₆₆ and (TTF)Cu(SCN)₂ have been investigated by infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. (TTF)(SCN)₀ͺ₆₆ crystallized in a tetragonal space group with a disordered column of thiocyanate anions. (TTF)Cu(SCN)₂ is an insulator with a two-dimensional network of Cu(SCN)₂⁻ ions. X-ray crystal structures of four compounds prepared in association with copper complex chemistry have been determined; (1) 5,5'-dibromo-2,2'-bithiophene, (2) 3,5,5'-tribromo-2,2'-bithiophene, (3) Cu(dmp)(CN)₂ ⁻ · Bu₄N⁺ and (4) the 1:2 adduct of dimercaptosuccinic acid and dimethylformamide.

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Leung, Wai-ho Wilkie. "Synthesis, reactivities and electrochemistry of ruthenium and osmium oxo complexes with polypyridine ligands /". [Hong Kong : University of Hong Kong], 1989. http://sunzi.lib.hku.hk/hkuto/record.jsp?B12474332.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Hui, Ching-sum, e 許正心. "Study of photosensitizing properties in some rhenium diimine complex containing polymers". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B26666650.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

6

McQuaid, Michael James. "Spectroscopic characterization of metal-based complexes and metal-based complex oxidation processes". Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/30334.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Stander, Elzet. "Nuwe reaksies van gedeprotoneerde Fischer-tipe karbeenkomplekse". Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/1222.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Salam, Md Abdus. "Studies in vanadium chemistry /". Title page, contents and summary only, 1986. http://web4.library.adelaide.edu.au/theses/09PH/09phs1595.pdf.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

9

Simpson, Linda. "Trivalent group 13 metal complexes of N-substituted-3-hydroxy-2-methyl-4-pyridinones". Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28885.

Testo completo

Abstract (sommario):

The compounds tris(N-ռ-propyl-3-hydroxy-2-methyl-4-pyridinonato) aluminum(III), -gallium(III), and -indium(III) and tris(N-ռ-butyl-3-hydroxy-2-methyl-4-pyridinonato)aluminum(III), -gallium(III), and -indium(III) were synthesized. All six compounds were prepared via the metal template effect. They were characterized by IR, FAB-MS, ¹H NMR, ²⁷Al NMR, and elemental analysis. Three of the six complexes were studied by single-crystal X-ray diffraction. They formed trihydrates, unlike their N-methyl and N-ethyl analogues, which formed dodecahydrates. The ռ-butyl complex Al(C₁₀H₁₄N0₂)₃‧3H₂0 (1) and ռ-propyl complexes Al(C₉H₁₂N0₂)₃‧3H₂0 [2], and Ga(C₉H₁₂N0₂)₃‧3H₂0 {3} were basically isostructural, crystallizing in the space group P3 with the following crystal parameters for 1, [2], and {3}: α= 15.885 (1) ([15.328 (1)], {15.367 (2)}) Å, c = 7.280 (8) ([7.2321 (2)], {7.256 (2)}) Å, Z = 2. The data were refined by using 1280 ([1377], {1802}) reflections with I>3σ(I) to R and Rա values of 0.047 ([0.057], {0.055)) and 0.061 ([0.077], {0.081}), respectively. The complexes exist as the rigidly fac geometries with infinite chains of hydrogen bonds parallel to the c axis.
Science, Faculty of
Chemistry, Department of
Graduate

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Birtles, John. "Solution based studies of tetranuclear (mu₄-oxo)-Cu(II) complexes /". Thesis, Connect to Dissertations & Theses @ Tufts University, 2004.

Cerca il testo completo

Abstract (sommario):

Thesis (Ph.D.)--Tufts University, 2004.
The [mu] in the title is depicted as a Greek letter mu, followed by a subscript 4. Adviser: Samuel P. Kounaves. Submitted to the Dept. of Chemistry. Includes bibliographical references. Access restricted to members of the Tufts University community. Also available via the World Wide Web;

Gli stili APA, Harvard, Vancouver, ISO e altri

11

Mitchell, S. H. "Structural studies on some complex compounds containing imines". Thesis, Cardiff University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332450.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

12

Ko, Hyunjin. "Structural and electronic investigations of complex intermetallic compounds". [Ames, Iowa : Iowa State University], 2008.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

13

Williams, Michael Lloyd. "New aspects of organometallic chemistry /". Title page, contents and abstract only, 1985. http://web4.library.adelaide.edu.au/theses/09PH/09phw725.pdf.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

14

梁偉豪 e Wai-ho Wilkie Leung. "Synthesis, reactivities and electrochemistry of ruthenium and osmium oxo complexes with polypyridine ligands". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1989. http://hub.hku.hk/bib/B31231883.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

15

Khotseng, Lindiwe Eudora. "Separation and speciation of biodegradable complexes using capillary zone electrophoresis". Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/50092.

Testo completo

Abstract (sommario):

Thesis (PhD)--Stellenbosch University, 2004.
ENGLISH ABSTRACT: Separation of the metal ions Cu2+, Pb2+, Cd2+ Mn2+, Cr3+, Fe3+ and Zn2+ with poly ethylenediamine tetra-acetic acid (EDTA), ethylenediamine disuccinic acid ([S,S']- EDDS) and ethylenediamine dimalonic acid (EDDM) was performed by Capillary Electrophoresis. The electropherograms obtained by Capillary Electrophoresis were validated with a speciation model Joint Expert Speciation System (JESS). Excellent agreement was observed for the speciation diagrams for these species with the pH curves determined by capillary electrophoresis with those determined by speciation modelling using JESS. The ligands EDDS and EDDM are readily biodegradable. They have been proposed as substitute ligands for EDTA. Detection of the above species was performed using both an electrochemical and a UV detector. The obtained electropherograms were used for the determination of the detection limits of these species. The electrochemical detector has a lower detection limit for these species than the UV detector in conformity with reported literature for these detectors.
AFRIKAANSE OPSOMMING: Skeiding van die metaal ione Cu2+, Pb2+, Cd2+, Cr3+, Fe3+ en Zn2+ met behulp van etileendiamientetra-asyn suur (EDTA), etileendiamiendisuksien suur ([S,S']-EDDS) en etileendiamiendimaleen suur (EDDM) was gedoen deur kapilêre elektroferose. Die elektroferogramme, verkry deur kapilêre elektroferose was gebruik om die spesiasie model "Joint Expert Speciation System (JESS)" te valideer. Uitstekende ooreenstemming was waargeneem vir die verspreidings diagramme van hierdie spesies as 'n funksie van pH wat verkry was deur kapilêre elektroferose met die' wat vasgestel was deur die spesiasie modeleeringsproses van JESS. Die ligande EDDS en EDDM toon onmiddelike biodigradeerbaarheid. Hulle was voorgehou as alternatiewe ligande vir EDTA. Bepaling van die bogenoemde spesies was ook gedoen deur beide elektrochemiese en UV deteksie. Deur gebruik te maak van hierdie detektore was die deteksie limiete van hierdie spesies bepaal. Die elektroochemiese detektor het 'n laer deteksie limiet vir hierdie spesies in vergelyking met die UV detector. Dit stem ooreen met die literatuur vir hierdie detektore.

Gli stili APA, Harvard, Vancouver, ISO e altri

16

Khotseng, Lindiwe Eudora. "Separation and speciation of biodegradable complexes using capillary zone electrophersis". Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/52052.

Testo completo

Abstract (sommario):

Thesis (PhD)--Stellenbosch University, 2004.
ENGLISH ABSTRACT: Separation of the metal ions Cu2+, Pb2+, Cd2+ Mn2+, Cr3+, Fe3+ and Zn2+ with poly ethylenediamine tetra-acetic acid (EDTA), ethylenediamine disuccinic acid ([S,S']- EDDS) and ethylenediamine dimalonic acid (EDDM) was performed by Capillary Electrophoresis. The electropherograms obtained by Capillary Electrophoresis were validated with a speciation model Joint Expert Speciation System (JESS). Excellent agreement was observed for the speciation diagrams for these species with the pH curves determined by capillary electrophoresis with those determined by speciation modelling using JESS. The ligands EDDS and EDDM are readily biodegradable. They have been proposed as substitute ligands for EDTA. Detection of the above species was performed using both an electrochemical and a UV detector. The obtained electropherograms were used for the determination of the detection limits of these species. The electrochemical detector has a lower detection limit for these species than the UV detector in conformity with reported literature for these detectors.
AFRIKAANSE OPSOMMING: Skeiding van die metaal ione Cu2+, Pb2+, Cd2+, Cr3+, Fe3+ en Zn2+ met behulp van etileendiamientetra-asyn suur (EDTA), etileendiamiendisuksien suur ([S,S']-EDDS) en etileendiamiendimaleen suur (EDDM) was gedoen deur kapilêre elektroferose. Die elektroferogramme, verkry deur kapilêre elektroferose was gebruik om die spesiasie model "Joint Expert Speciation System (JESS)" te valideer. Uitstekende ooreenstemming was waargeneem vir die verspreidings diagramme van hierdie spesies as 'n funksie van pH wat verkry was deur kapilêre elektroferose met die' wat vasgestel was deur die spesiasie modeleeringsproses van JESS. Die ligande EDDS en EDDM toon onmiddelike biodigradeerbaarheid. Hulle was voorgehou as alternatiewe ligande vir EDT A. Bepaling van die bogenoemde spesies was ook gedoen deur beide elektrochemiese en UV deteksie. Deur gebruik te maak van hierdie detektore was die deteksie limiete van hierdie spesies bepaal. Die elektroochemiese detektor het 'n laer deteksie limiet vir hierdie spesies in vergelyking met die UV detector. Dit stem ooreen met die literatuur vir hierdie detektore.

Gli stili APA, Harvard, Vancouver, ISO e altri

17

Liao, Jing-Piin. "Investigation of Copper-Natural Ligand Complexes by RP-HPLC Photodiode Array UV-VIS and Fluorescence Detection". Thesis, University of North Texas, 1992. https://digital.library.unt.edu/ark:/67531/metadc332502/.

Testo completo

Abstract (sommario):

In this study, reversed phase HPLC with dual UV photodiode (PDA) and fluorescence (FL) detection were used to investigate copper complexes with fulvic, caffeic, vanillic, salicylic, and adipic acids. Application of the RE method provided valuable information on the retention behavior and spectral characteristics of FA and model compounds. Even though the method was only applicable to VA, the use of the PDA detector allowed the UV-V is scanning of the separated peaks. This allowed the comparison between the UV-Vis spectra of uncomplexed species. The overall results provide an experimental framework for validation of the proposed Cu-humate interaction models.

Gli stili APA, Harvard, Vancouver, ISO e altri

18

Cheung, Ka Man. "Syntheses and reactivity of cyclometalated iridium and ruthenium complexes /". View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?CHEM%202005%20CHEUNG.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

19

Yip, Sung-kong. "Design, synthesis, characterization and luminescence properties of alkynylgold(I) complexes strategies towards supramolecular architectures and host guest chemistry /". Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B31941734.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

20

Tong, Wai-yip, e 唐煒燁. "Luminescent platinum(II) complexes containing dianionic tetradentate ligands having mixed oxygen, nitrogen and carbon donor atoms and platinum(II)-containing phosphorescent polymers : synthesis, photophysical properties and material applications". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/198829.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

21

Lam, Ngai Man. "Synthesis, crystal structures, and reactivity of ruthenium and osmium nitrido complexes /". View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?CHEM%202006%20LAMN.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

22

Habtu, Michael M. "A study of the transport, extraction and co-ordination chemistry of a number of thiourea ligands with a series of transition and post-transition metal ions". Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/97374.

Testo completo

Abstract (sommario):

Thesis (MSc)--Stellenbosch University, 2003.
ENGLISH ABSTRACT: In this study, a number of mono- and di-substituted acyl(aroyl)thioureas were investigated for potential application as specific carriers (ionophores) for the transport and extraction of Ag(l) from a mixture of Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Pb(lI) ions. The experimental arrangement for the transport experiments employed a liquid membrane set up involving a 3-phase system - 2 aqueous phases (source and receiving phase) separated by a chloroform membrane incorporating the ligand. Competitive metal ion transport experiments were conducted using the liquid membrane set up. The aqueous source and receiving phases were analyzed using Atomic Absorption Spectroscopy (AAS) and results were confirmed by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICPOES). The transport results show that the N,N-dialkyl-substituted-N'-acyl(aroyl) (HL) thioureas studied, with the exception of the N,N-di-(2-hydroxyethyl)-N'-benzoylthiourea (HL3 ) and N-piperidyl-N'-4-nitrobenzoylthiourea (HL9 ), were efficient and selective for Ag(I). HL9 was also selective for Ag(l) but not efficient. HL3 was selective for Cu(II). Under the experimental conditions employed, 13% Cu(lI) was transported by HL3 . Among the N,Ndialkyl- N'-aroylthioureas, maximum Ag(l) transport was obtained by using N,N-diethyl-N'-4- chlorobenzoylthiourea (HL5 ) and N,N-di-n-butyl-N'-benzoylthiourea (HL \ Under the experimental conditions employed, the percentages of Ag(l) transported by HL5 and HL 1 were 48% and 42% respectively. The transport selectivity and efficiency of 3,3,3' ,3'-tetraethyl-1 ,1'-isophthaloylbisthiourea (H2L12 ) and N,N-diethyl-N'-camphanoylthiourea (HL13)for Ag(l) were also studied. We were particularly interested, in comparing the Ag(l) transport and extraction efficiency of these ligands with that of the HL and H2L ligands. The experimental results reveal that, of all the ligands we investigated in this study, HL 13 was the most efficient and selective carrier for Ag(l) transport. The interesting result is that, depending on the ligand concentration used, HL 13 transported 71-81% of Ag(I). Competitive two-phase metal ion solvent extraction experiments were also performed under conditions similar to the transport studies. The results show that by varying the ligand concentration in the membrane phase, up to 100% Ag(l) can be selectively and efficiently extracted from the mixture of the seven metal ions. Finally, the N,N-di-(n)-butyl-N'-benzoylthiourea (HL1) ligand and its complex with Ag(l) were synthesized. Single crystals of the complex were grown for X-ray crystallography and the crystal and molecular structure of the complex was determined. The crystal structure showed that Ag(l) is bonded to the deprotonated ligand through the S,O atoms forming interesting cluster [Ag (L - S, 0)] 4 in the solid state. This structure is monoclinic and crystallizes in the space group P21!c with a = 17.805 (4) A, b = 21.759 (4) A, c = 36.438 (7) A, f3= 96.34(3)°, Z = 8 and a final R-factor of 5.4%.
AFRIKAANSE OPSOMMING: In hierdie proefskrif is 'n aantal mono- en di-gesubstitueerde asiel(ariel) tioureums ondersoek vir moontlike gebruik as ionofore (spesifieke draers) vir die transportasie en ekstraksie van Ag(l) vanuit 'n mengsel van Co(ll), Ni(II), Cu(II), Zn(II), Cd(II), Ag(l) en Pb(lI) ione. 'n Drie-fase selsisteem is gebruik vir die transportasie eksperimente, twee waterige fases (bron- en ontvang-fase) wat geskei is met die chloroform membraan fase wat die ligande bevat. Kompeterende metaalioon transportasie eksperimente is uitgevoer met behulp van hierdie vloeistof membraan stelsel. Die twee waterige fases is deur middel van Atoomabsorpsie Spektroskopie (AAS) ge-analiseer en resultate is bevestig met gebruik van Induktief-gekoppelde Plasma-Optiese Emissie Spektroskopie (IGP-OES). Die resultate het getoon dat elkeen van die N,N-dialkiel-gesubstitueerde-N'-asiel(ariel) (HL) tioureums, met uitsondering van N,N-di(2-hidroksie-etiel)-N'-benzieltioureum(HL 3) en Npiperidiel- N'-4-nitrobenzieltioureum(HL9 ), doeltreffend en selektief was vir Ag(l) transportasie. HL9 was selektief vir Ag(I), maar die transportasie waarde was nie hoog nie, dws. dit was nie doeltreffend nie. HL3 was selektief vir Cu(II). Met gebruik van ons eksperimentele kondisies is 13% Cu(lI) getransporteer deur HL 3. Van die N,N-dialkiel-N'- ariel tioureums, is maksimum transportasie van Ag(l) verkry met gebruik van N,N-dietiel- N'-4-chlorobenzieltioureum (HL5) en N,N-di-n-butiel-N'-benzieltioureum (HL1). Met gebruik van ons eksperimentele kondisies was die persentasie transportasie van Ag(l) deur HL5 en HL 1 48% en 42% onderskeidelik. Die selektiwiteit en doeltreffendheid van 3,3,3' ,3'-tetra-etiel-1 ,t-isoftaltelblstioureumtl+L 12) en N,N-di-etiel-N'-kamfonieltioureum (HL13) vir Ag(l) transportasie is ook onderneem. Ons was besonder ge-interesseerd om die Ag(l) transportasie en ekstraksie van hierdie ligande te vergelyk met dié van die HL en H2L tipe ligande. Die eksperimentele resultate het getoon dat van al die ligande wat bestudeer is, HL 13 die doeltreffendste en mees selektiewe ionofoor was. Van besondere, belang was dat, afhangend van die ligand konsentrasie wat gebruik is, HL13 71-81% Ag(l) getransporteer het. Kompeterende twee-fase metaalioon vloeistof-vloeistof ekstraksie eksperimente is ook uitgevoer onder toestande soortgelyk aan dié van die transportasie eksperimente. Die resultate toon dat met varierende ligand konsentrasie, tot soveel as 100% Ag(l) selektief en doeltreffend geëkstrakeer word vanuit 'n mengsel van die sewe metaal ione. N,N-di-n-butiel-N'-benzieltioureum (HL1 ) ligande en die kompleks daarvan met Ag(l) is ook gesintetiseer. Enkel-kristalle van die kompleks is verkry en X-straal kristallografiese analiese is onderneem. Die kristalstruktuur toon hoedat Ag(l) gebind is aan die gedeprotoneerde ligand deur die S en Q atome en toon ook interessante [Ag(L-S,Q)]4 groepe in die vaste toestand. Hierdie struktuur is monoklinies en kristaliseer in die ruimtegroep P21!c met a = 17.805(4) Á, b = 21.759(4)Á, c = 36.438(7)Á, P = 96.34(3t, z = 8 en 'n finale R-faktor van 5.4%.

Gli stili APA, Harvard, Vancouver, ISO e altri

23

Yohannes, Desta Yonas. "Synthesis and electrochemistry of biodegradable ligands - iminodiglutaric acid and iminoglutaricsuccinic acid - and their complexes with selected metal ions (Zn²⁺, Cd²⁺, Cu²⁺)". Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/50112.

Testo completo

Abstract (sommario):

Thesis (MSc)--Stellenbosch University, 2004.
ENGLISH ABSTRACT: Two new potentially biodegradable aminopolycarboxylic acid ligands, iminodiglutaric acid tetra sodium salt (IDG-4Na) and iminoglutaricsuccinic acid tetra sodium salt (IGS- 4Na), were synthesized in reasonably good yield and purity. The commercially unavailable precursor for the two ligands, ethyl p-aminoglutarate, was synthesised in high yield and purity, and together with the two ligands were fully characterized by means of melting point measurements and various spectrometric techniques CH-NMR, 13C-NMR, MS and IR). For the first time, an electrochemical study has been conducted on the complexes of these ligands with selected transition metal ions (Zn2+, Cu2+ and Cd2+). An electrochemical technique, cyclic voltammetry (CV), was utilized on the study of the complexing ability of the ligands to the selected metal ions. An electrochemical cell comprising three electrodes was employed: thin film mercury coated carbon microelectrode was used as the working electrode, a Platinum wire as the auxiliary electrode, and a Ag/AgCI as the reference electrode. CV has been used and proven to offer a convenient route towards the determination of metal-ligand complex stability constants in aqueous media". The values of the logarithms of the metal-ligand formation constants obtained by this technique, when compared with other widely used aminopolycarboxylic acids (APCAs), show better complexing ability of the ligands with the transition metal ions. When the two ligands are compared, IGS showed greater affinity towards the selected transition metal ions. This is due to the fact that, in aqueous media, as the side chain ligators decrease, the stabilization energy of the complex increases. The formation stability constants were determined by plotting the change in the reduction potential (ΔE) against solution pH. A process making use of a modification of lingane equation was used.
AFRIKAANSE OPSOMMING: Twee nuwe potensieel bio-afbreekbare amienpolikarboksielsuurligande, iminobiglutaarsuur -tetranatriumsout (IBG-4Na) en iminoglutaarsuksiensuurtetranatriumsout (IGS-4Na), was vervaardig met redelike goeie opbrengs en suiwerheid. Die kommersïeel onverkrygbare voorloper van die twee ligande, etiel-B-aminoglutaraat, was berei met hoë obrengs en suiwerheid, en was saam met die twee ligande ten volle geïdentifiseer deur middel van smeltpunt bepalings en verskeie spektrometriese tegnieke CH-KMR, 13C-KMR, MS en IR.). Vir die eerste keer is 'n elektrochemiese studie uitgevoer op die komplekse van hierdie ligande met selektiewe oorgangsmetaalione (Zn2+, Cu2+, en Cd2+). 'n Elektrochemiese tegniek, sikliese voltametrie (SV), is gebruik om die komplekseringsvermoë van die ligande ten opsigte van die geselekteeerdr metaalione te bestudeer. 'n Elektrochemiese sel wat bestaan uit drie elektrodes is gebruik: 'n Dunlaag kwikelektrode bedek met koolstof is gebruik as die werkselektrode, 'n platinumdraad as die bykomende elektrode en 'n Ag/AgCI elektrode as die verwysingselektrode. SV is voorheen gebruik en bewys as 'n gerieflike metode vir die bepaling van metaalligandkompleksstabiliteitskonstantes in waterige media'. Die waardes van die logaritmes van die metaalligandvormingskonstantes wat verkry word deur hierdie tegniek, soos vergelyk met ander algemeen gebruikte amienpolikarboksielsure (APKSe), vertoon beter komplekseringsvermoë met die ligande deur middel van die oorgangsmetaalione. Wanneer die twee ligande met mekaar vergelyk word, het IGS-4Na groter affiniteit gehad vir die oorgangsmetaalione. Dit is as gevolg van die feit dat die stabiliteitsenergie van die kompleks in waterige media verminder word soos wat die sykettings van die ligande toeneem. Die vormingstabilitietskonstantes was bepaal deur 'n varandering in reduksie potensiaal (ΔE) teenoor die pH van die oplossings te plot. Die grafieke is verkry deur 'n aanpassing van die Lingnane-vergelyking te gebruik.

Gli stili APA, Harvard, Vancouver, ISO e altri

24

Ng, Fei-yeung. "Structure and properties of self-assembled coordination compounds : homoleptic d10-metal aryl/alkylacetylides, ruthenium n-heterocycles and picolinates". View the Table of Contents & Abstract, 2006. http://sunzi.lib.hku.hk/hkuto/record/B36587126.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

25

Clarke, Ronald James. "Kinetic and equilibrium studies of cyclodextrin-azo dye inclusion complexes /". Title page, contents and abstract only, 1985. http://web4.library.adelaide.edu.au/theses/09PH/09phc5992.pdf.

Testo completo

Abstract (sommario):

Thesis (Ph. D.)--University of Adelaide, Dept. of Physical and Inorganic Chemistry, 1985.
Offprints of two author's journal articles inserted at end of the v. Includes bibliographical references (leaves 10-12).

Gli stili APA, Harvard, Vancouver, ISO e altri

26

Ng, Fei-yeung, e 吳飛洋. "Structure and properties of self-assembled coordination compounds: homoleptic d10-metal aryl/alkylacetylides, ruthenium n-heterocyclesand picolinates". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B37878566.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

27

Wolfgong, William J. "Solvent and Ionic Complexes of the Calix[6]arenes". Thesis, University of North Texas, 1997. https://digital.library.unt.edu/ark:/67531/metadc278436/.

Testo completo

Abstract (sommario):

One of the more attractive attributes of calixarenes is their wide variety of possible conformations and hence cavity shapes. However, the flexibility that allows this long-range benefit gives rise to major synthetic challenges when working with the larger members of the family. O-alkylations have proven to be the most widely employed synthetic routes to "functionalization" of the calixarenes, and these have shown a dependence upon both solvent and the metal ions present. Surprisingly, there have been no structural data presented concerning the complexes between the simple unsubstituted calix[6]arenes and the metal ions of groups 1 and 2. The structures of four complexes, containing cesium, rubidium, and calcium are reported as determined by X-ray crystallography. The solution behavior of the complexes for both representative groups is also discussed, in particular with regard to conformational stabilization of the calix[6]arenes and the role of solvent upon this stabilization. These complexes are also investigated as starting materials for the selective functionalization of the calix[6]arenes.

Gli stili APA, Harvard, Vancouver, ISO e altri

28

Tikilili, Phumza Vuyokazi. "Biodegradation of complex aromatic compounds in nuclear process water". Diss., University of Pretoria, 2010. http://hdl.handle.net/2263/25979.

Testo completo

Abstract (sommario):

Nuclear energy generation results in the production of effluents and radioactive waste that are very difficult to treat and dispose. A considerable fraction of nuclear waste is discharged in the form of complex mixtures of hazardous organic compounds and metallic radionuclides. The most serious pollution is caused by polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls that are very difficult to remove from the environment. The nuclear industry faces certain challenges related to treatment and safe disposal of these mixed radioactive organic wastes due to the toxicity and recalcitrant nature of the organics. Techniques currently used in treating the waste include physical-chemical processes that have resulted in the generation of the secondary waste requiring further treatment before disposal to the environment. These conventional processes also require the use of strong oxidising agents and higher than natural pH and temperature. Therefore, it is of great importance to develop new environmentally friendly technologies. One suggested method employs specialised cultures of bacteria to completely mineralize the organic compounds without leaving traces of harmful byproducts. The efficiency of bacteria to remove these types of compounds may be improved by in situ application. During in situ application, the bacteria apply a variety of pathways to break down the compounds and use them as their energy and carbon sources. These processes may be carried out within the natural pH and temperature range capable of supporting life forms. In the current study, a more detailed analysis of the biodegradation capability of the organic compounds was conducted and the following were the major findings of the study:

Wastewater from an actual radionuclide processing facility was characterised and was found to contain all the 16 priority PAHs in the range 0.001-25 mg/L. Acenaphthene (detected at 25.1 mg/L) was the most abundant. Most of the PAHs in the wastewater samples exceeded the WHO limit of 0.05ìg/L indicating the need for further treatment before final disposal to the environment.
After purifying and sequencing the rRNA genes from the soil and mine water bacteria, a total of 5 and 3 bacterial isolates were found, respectively. The rRNA sequences were isolated from bacteria with some tolerance to PAH toxicity and were thus candidate species for naphthalene degradation. The bacteria from soil were predominated by aromatic compound degraders Pseudomonas aeruginosa, Microbacterium esteraromaticum and Alcaligenes sp. In mine water, only Pseudomonas putida was identified as a known aromatic ring cleaving species.
The biodegradation of naphthalene by the purified cultures was determined to be limited by its solubility (30mg/L) and toxic effects of the aromatic compounds. A kinetic model was derived based on the metabolism and microbial growth kinetics. The model predicted the concentration remaining in solution under different initial (added) PAH concentrations. A simplified coupled dissolution-degradation model was used to model the kinetics of degradation. With help of the model, parameters were estimated and the sensitivity of parameter value was also evaluated. The aim of model was to help gain a better understanding of biological degradation. This could be used for optimisation of the process and scale up of the process to pilot and full-scale application.

Dissertation (MSc)--University of Pretoria, 2011.
Microbiology and Plant Pathology
unrestricted

Gli stili APA, Harvard, Vancouver, ISO e altri

29

Liu, Li. "The chemistry of luminescent mercury (II) alkynyl complexes and their platinum (II) and gold (I) counterparts". HKBU Institutional Repository, 2005. http://repository.hkbu.edu.hk/etd_ra/627.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

30

Lock, Julia. "Cyclodextrins : molecular wheels for supramolecular chemistry /". Title page, table of contents and abstract only, 2004. http://web4.library.adelaide.edu.au/theses/09PH/09phl8131.pdf.

Testo completo

Abstract (sommario):

Thesis (Ph.D.)--University of Adelaide, School of Chemistry and Physics, Discipline of Chemistry, 2005?
"July 2004" Includes copies of publications by the author as appendix. Includes bibliographical references.

Gli stili APA, Harvard, Vancouver, ISO e altri

31

Tang, Yongping. "Investigation of the stereochemistry of macrocyclic ligand complexes: [Ni(tetramethylcyclam)][superscript]2+ and [brace]Co(Me[subscript]6[14]dieneN[subscript]4)CI[subscript]2+[brace]". Thesis, Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/26951.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

32

Foster, Keith A. "Preparative, structural, and electrochemical investigation of metal complexes of tetraazamacrocyclic ligands containing tertiary amine donors". Diss., Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/30370.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

33

Pan, Jie. "Organometallic porphyrin based complexes for photophysical and biological application". HKBU Institutional Repository, 2016. https://repository.hkbu.edu.hk/etd_oa/331.

Testo completo

Abstract (sommario):

This thesis focuses on the development of porphyrin-based complexes as multi-modal bio-imaging probes. Detailed studies of photophysical and biological properties were included.;In chapter 1, the general background of porphyrin and its derivatives, their structure specialty, synthetic methods, photophysical properties, and applications in biological system were described.;Curcumin-bridged porphyrin-copper complex (Por-Cu-Cur) which can permeate through the high blood-brain barrier, accumulate fast in brain tissues, and emit brilliant and stable two photon excited emission has been developed. Apart from this, Por-Cu-Cur shows high binding affinity for Ab fibrils, and decent inhibitory effect on the fibrillation of Ab1-42 peptides, as well as low toxicity to neuro-derived SK-N-SH cells in vitro and particularly in vivo in transgenic mice.;The design and synthesis of amphiphilic porphyrin linked ruthenium complexes were described. We focus on the photophysical studies of its UV-Vis absorption spectrum, fluorescence spectrum, solvatochromism, and singlet oxygen phosphorescence. The converse energy transfer mechanism of porphyrin-ruthenium complexes and zinc-porphyrin-ruthenium complexes has been clearly studied. Subcellular localization, dark cytotoxicity and photodynamic therapy has been well studied, which efficiency correspond to the energy transfer mechanism.;Based on the previous study, we would like to provide a proof-of-concept model - labelling (hot/cold) gallium in porphyrin-based complex with a short reaction time (but with high reaction yield) and aim to develop a multi-modal bioprobe for photodynamic therapy, optical imaging and positron emission tomography in one piece. An amphiphilic hot gallium-porphyrin-ruthenium compound has been synthesized (GaporRu-1) with reaction time of 15 minute and 85 % yield. The acidity of GaporRu-1 enables selective subcellular localization in lysosome. It also has an good singlet oxygen quantum yield (61.4 %), which proves its great potential for further in vivo study for as both PDT and PET agents.;Experimental details are shown in chapter 5. Including details of photophysical measurements, instrumentation and biological measurements.

Gli stili APA, Harvard, Vancouver, ISO e altri

34

Bolte, Stephanie Elizabeth. "Vanadium-51 solid state NMR of inorganic vanadium(V) dipicolinic acid complexes". Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 76 p, 2009. http://proquest.umi.com/pqdweb?did=1889078501&sid=7&Fmt=2&clientId=8331&RQT=309&VName=PQD.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

35

Ghebregziabiher, Berhe Haile. "Synthesis of chiral thiourea ligands and their transition metal complexes". Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53610.

Testo completo

Abstract (sommario):

Thesis (MSc)--Stellenbosch University, 2003.
ENGLISH ABSTRACT: Modification of chitosan with benzoylisothiocyanate was attempted, however due to solvent problem the study was left incomplete till appropriate solvent is designed. N,N-diethyl-N -camphanoylthiourea (HL8), N-piperidyl-N '-camphanoylthiourea (HL9), N-pyrrolidyl-N -camphanoylthiourea (HL10) and N,N-diethyl-N -adamantylcarbonyl thiourea (HL11)have been synthesised and characterised for the first time. Two of these ligands HL8 and HL11, were used to form a number of transition metal complexes, namely H30+{fae-[Co(L8-S,Obn, cis-[Ni(L8-S,0)2], trans-[Cu(L8-S,0)2], translcis-[Zn(L 8_S,0)2], translcis-[Pt(L 8_S,0)2], Ag2[(HL8-S)(L-J.1-S,O)]2, translcis- [Ni(L11-S,O)2]and translcis-[Cu(L11_S,O)2]. The new products are fully characterised by means of MS, IR spectroscopy, NMR spectroscopy, elemental (C, H, Nand S) analysis and melting point determinations. The H30+{fae-[Co(L8-S,Obn, cis-[Ni(L8- S,O)2], trans-[Cu(L8-S,O)2] and Ag2[(HL8-S)(L-J.1-S,O)]2 are also characterised by Xray diffraction analysis. The structure of the new chiral N,N-dialkyl-N' -camphanoylthiourea ligand (HL8) has a significant effect on its coordination chemistry with transition metal ions. This ligand forms H30+ {fae-[Co(L8-S,Obn, cis-[Ni(L8-S,0)2], trans-[Cu(L-S,O)2] and Ag2[(HL8- S)(L8-J.1-S,O)]2 complexes with the Co(II), Ni(II), Cu(II) and Ag(I) metal ions respectively. The spectroscopic and X-ray diffraction results of these complexes indicate a bidentate mode of coordination of the ligand (with its Sand °donor atoms) to the Co(II), Ni(II) and Cu(II) metal ions. The reaction of this ligand with silver(I) however affords the formation of a binuclear silver(I) complex exhibiting monodentate and bidentate modes of coordination within the same complex. The exclusive formation of trans-[Cu(L8-S,0)2] is a new phenomenon for the HL type thiourea ligands with Sand °donor atoms. Up to this point a maximum of 15 % trans-isomer has been reported in ltterature." All the transition metal complexes made with HL8and HL11are air stable in both the liquid and solid states except the H30+{fae-[Co(L 8-S,Ob]} Interestingly the deep green fae- H30+{fae-[Co(L8-S,Obn complex is air sensitive and the Co(II) oxidizes to Co(III) in the complex by atmospheric O2. The oxidation of Co(II) to Co(III) in the complex is confirmed by 1Hand 13CNMR spectra as well as by UV-Visible spectra of the complex. The NMR spectra of the complexes indicated the presence of one isomer in each complex except for the NMR spectra of the platinum complex of the HL8 ligand. The presence of the minor trans-[Pt(L8-S,Q)21 isomer in combination with the major cis-[Pt(L8-S,Q)21 isomer in the platinum complex was indicated by the 1H, 13Cand 195ptNMR spectra of the complex.
AFRIKAANSE OPSOMMING: Pogings om chitosan met benzoylisothiocyanate te modifiseer is onvoltooid gelaat weens die gebrek aan'n geskikte oplosmiddel. N,N-diethyl-N -carnphanoylthiourea (HL8), N-piperidyl-N -camphanoylthiourea (HL9), N-pyrrolidyl-N -camphanoylthlourea (HL10) en N,N-diethyl-N -adamantylcarbonyl thiourea (HL11) is vir die eerste keer gesintetiseer en gekarakteriseer. Twee van die ligande, HL8 en HL11, is gebruik om verskeie oorgangsmetaalkomplekse te berei, nl. H30+{fac-[Co(L8-S,Ohn, cis-[Ni(L8-S,0)2], trans-[Cu(L8-S,0)2], trans/cis-[Zn(L8 - S,0)2], trans/cis-[Pt(L8-S,0)2], Ag2[(HLB-S)(L-jl-S,0)]2, trans/cis-[Ni(L11-S,0)2] en trans/cis-[Cu(L11_S,0)2]. Die nuwe produkte is volledig gekarakteriseer deur middel van MS, IR spektroskopie, KMR spektrometrie, elemente (C, H, N en S) analise en smeltpuntbepaling. Die komplekse H30+{fao-[Co(L8-S,0)3n, cis-[Ni(L8-S,0)2], trans- [Cu(L8-S,0)2] en Ag2[(HLB-S)(L-jl-S,0)]2 is ook deur middel van X-straaldiffraksieanalise gekarakteriseer. Die struktuur van die nuwe chirale N,N-dialkyl-N'-camphanoylthiourea ligand (HL8) het In beduidende invloed op die koordinasie van hierdie ligand met oorgangsmetaalione. Die ligand vorm H30+{fac-[Co(L8-S,Ohn, cis-[Ni(L8-S,0)2], trans-[Cu(L-S,0)2] en Ag2[(HL8-S)(L8-Il-S,0)]2 komplekse met Co(ll)-, Ni(II)-, Cu(II)- en Ag(I)-ione respektiewelik. Spektroskopiese en X-straaldiffraksie-analise van die komplekse toon dat die ligande op 'n bidentate wyse d.m.v. die S- en O-donoratome met Co(II), Ni(lI) en Cu(lI) koordineer. Die reaksie van hierdie ligand met Ag(I)-ione lei egter tot die vorming van 'n dikernige silwer(I)-kompleks waarin die ligande monodentaat (S) en bidentaat (S en 0) aan die metaal gebind is. Die vorming van uitsluitlik die trans-[Cu(L8-S,0)2] in die reaksie van HL8 met Cu(lI) is 'n besondere fenomeen in die chemie van hierdie tipe ligande; in die literatuur word melding gemaak van slegs een ander trans-kompleks met hierdie ligande, en dan wel met 'n maksimum opbrengs van 15%.29 Alle oorgangsmetaalkomplekse met HLB en HL11 is stabiel indien blootgestel aan lug, ongeag of die verbindings opgelos word of in die vastetoestand verkeer, behalwe H30+{fao-[Co(L8-S,Ohn. Die diep-groen gekleurde H30+{fao-[Co(L8-S,Ohn)3]} kompleks is lugsensitief; Co(lI) word deur lugsuurstof na Co(lIl) ge-oksideer. Die oksidasie in die kompleks kan deur middel van 1H en 13CKMR spektrometrie sowel as UV-sigbare spektrofotometrie bevestig word. Die KMR spektra van alle komplekse dui op die teenwoordigheid van slegs een isomeer in oplossing, behalwe in die geval van die platinum(lI) kompleks met HL8. Die teenwoordigheid van lae konsentrasies trans-[Pt(L8-S,0)2] isomeer tesame met veel hoër konsentrasies van die cis-[Pt(L8 -S,O)2] isomeer word deur 1H, 13Cen 195ptKMR spektroskopie aangedui.

Gli stili APA, Harvard, Vancouver, ISO e altri

36

Pinkes, John R. "The attempted synthesis of novel bis (quadridentate) niobium (IV) complexes and the analyses of the products resulting from the attempted synthesis of tetrakis (8-hydroxyquinolinato) niobium (IV) /". Online version of thesis, 1989. http://hdl.handle.net/1850/10690.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

37

Hung, Ling-ling. "Novel luminescent cyclometalated gold (III) alkynyls design, synthesis, photophysics and their multinuclear assemblies /". Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B3963453X.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

38

何國強 e Kwok-keung Paul Ho. "Molecular structures and physicochemical properties of some chiral andhelical transition metal complexes with polypyridines and tetradentateanionic ligands". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1996. http://hub.hku.hk/bib/B31234884.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

39

He, Xiaoming. "Design, synthesis and characterization of alkynyl- and thiolato- gold (I) complexes with various receptor groups for host-guest chemistry". Click to view the E-thesis via HKUTO, 2010. http://sunzi.lib.hku.hk/hkuto/record/B43571979.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

40

Cheung, Kai-leung. "Syntheses and luminescence studies of di- and polynuclear gold(1) and copper(1) complexes, design strategies towards metalloreceptors and mixed-metal complexes /". Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk/hkuto/record.jsp?B23736136.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

41

Shea, James Christopher 1964. "Hyperfine structure in the microwave spectra of the iodine fluorides iodine heptafluoride and iodine pentafluoride and of the weakly bound complex hydrochloric acid...nitrous oxide". Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277178.

Testo completo

Abstract (sommario):

A pulsed-beam fourier transform microwave spectrometer was used to measure the rotational spectra of iodine heptafluoride, iodine pentafluoride, and the weakly bound complex, HCl...NNO. For IF7, only five rotational transitions were observed, and no resolvable hyperfine structure was detected. Based on this data, the A, B, and C rotational constants were determined to be 1746(3) MHz, 1732.0(8) MHz, and 1553.0(2) MHz, respectively. The existence of a pure rotational spectrum confirms that this molecule undergoes polar distortions. Twenty-two hyperfine components of the IF5 spectrum were recorded. The B rotational constant for this molecule was determined to be 2727.421(3) MHz, and the quadrupole coupling constant was found to be 1069.35(13) MHz. Though the work is still in progress on HCl...NNO, nine transitions have been recorded. In addition, five transitions have been recorded for an apparent trimer species composed of HCl, NNO, and an as yet unidentified third species.

Gli stili APA, Harvard, Vancouver, ISO e altri

42

Larkin, Scott A. "Synthesis and Supermolecular Chemistry of Biphenylthioatogold(I)Phosphine Complexes". Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/LarkinSA2007.pdf.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

43

Öberg, Mattias U. L. "Health risk assessment of dioxin-like compounds in complex samples /". Stockholm : Karolinska inst, 2003. http://diss.kib.ki.se/2003/91-7349-692-8.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

44

Lu, Huanjun. "Complex self-assembly of amphiphilic and polyphilic liquid crystalline compounds". Thesis, University of Sheffield, 2017. http://etheses.whiterose.ac.uk/19027/.

Testo completo

Abstract (sommario):

One of the most intriguing properties of liquid crystalline compounds is their ability to selfassembly into nanoscale entities, in the simplest cases as layers, columns, or spherical micelles, leading to their many applications in fields such as microelectronics, nanofabrication, medical etc. Understanding how such self-assembly can be controlled through molecular design is hence of paramount importance. Factors such as molecular shape and flexibility, interactions between different moieties, polarity and chirality all contribute to determine the exact mode of self-assembly of such a compound, as well as external controls through the use of temperature, solvent, electric and magnetic field. In this project three different series of compounds: X-shaped molecules, Polycatenar compounds, and Bolaamphiphiles with swallow-tailed side groups, were examined. Their complex modes of self-assembly have been studied using mainly X-ray diffraction methods, supplemented by Polarized Optical Microscopy, Differential Scanning Calorimetry, and for chiral phases Circular Dichroism Spectroscopy. In the X-shaped molecules, in addition to 'chess-board' two-coloured honeycomb columns with square cross-sections, several complex 3D phases with different tetragonal symmetries have been observed, their structures determined and molecular model constructed. In polycatenar compounds, we have studied the transitions from a recently found chiral isotropic phase (through dynamic mirror symmetry breaking of achiral compounds) to a bicontinuous cubic phase, either an achiral double network cubic or a chiral triple-network cubic phase. We have also found the formation of chiral SmQ phase in such achiral compounds, and have solved its structure - a long standing puzzle in liquid crystals for more than 30 years. In addition, a number of non-cubic phases, most of them suspected to be bicontinuous, have been identified and for most of them the space group symmetries have been determined, and tentative structural models proposed. In a number of bolaamphiphiles, with swallow-tailed side groups, a new single-diamond bicontinuous cubic phase has been discovered. The rigid aromatic cores are found to form bundles and such bundles form the segments of the single-diamond network with the side groups filling the rest of the space.

Gli stili APA, Harvard, Vancouver, ISO e altri

45

Suginome, Michinori. "Bis-silylation of Unsaturated Compounds Catalyzed by Palladium-Isocyanide Complex". Kyoto University, 1993. http://hdl.handle.net/2433/74624.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

46

Balkus, Kenneth John. "Metal complex faciliated transport and activation of molecular oxygen". Gainesville, FL, 1986. http://www.archive.org/details/metalcomplexfaci00balk.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

47

Sinha, Pankaj. "Phosphorescent Emissions of Coinage Metal-Phosphine Complexes: Theory and Photophysics". Thesis, University of North Texas, 2009. https://digital.library.unt.edu/ark:/67531/metadc12200/.

Testo completo

Abstract (sommario):

The major topics discussed are all relevant to the bright phosphorescent emissions of coinage metal complexes (Cu(I), Ag(I) and Au(I)) with an explanation of the theoretical background, computational results and ongoing work on the application in materials and optoelectronic devices. Density functional computations have been performed on the majority of the discussed complexes and determined that the most significant distortion that occurs in Au(I)-phosphine complexes is a near and beyond a T-shape within the P-Au-P angle when the complexes are photoexcited to the lowest phosphorescent excited state. The large distortion is experimentally qualified with the large Stokes' shift that occurs between the excitation and emission spectra and can be as large as 18 000 cm-1 for the neutral Au(I) complexes. The excited state distortion has been thoroughly investigated and it is determined that not only is it pertinent to the efficient luminescence but also for the tunability in the emission. The factors that affect tunability have been determined to be electronics, sterics, rigidity of solution and temperature. The luminescent shifts determined from varying these parameters have been described systematically and have revealed emission colors that span the entire visible spectrum. These astounding features that have been discovered within studies of coinage metal phosphorescent complexes are an asset to applications ranging from materials development to electronics.

Gli stili APA, Harvard, Vancouver, ISO e altri

48

Duan, Gongping. "Design, synthesis, and photophysics and photochromic study of dithienylethene-containing heterocyclic derivatives and N-heterocyclic carbene-ruthenium (II) complexes". Click to view the E-thesis via HKUTO, 2010. http://sunzi.lib.hku.hk/hkuto/record/B44248246.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

49

Myburgh, Jolanda. "Synthesis and characterization of novel platinum complexes : their anticancer behaviour". Thesis, Nelson Mandela Metropolitan University, 2009. http://hdl.handle.net/10948/d1018621.

Testo completo

Abstract (sommario):

In this dissertation novel non-leaving groups were employed to synthesize platinum complexes which can contribute to the understanding or improvement of anticancer action. These complexes basically consist of (NS)-chelate and amineplatinum complexes. Bidentate (NS)-donor ligands were used as non-leaving ligands in the syntheses of platinum(II) complexes with iodide, chloride, bromide and oxalate anions as leaving groups. These complexes were synthesized and studied since many questions regarding the interaction of sulfur donors and platinum still exists. These relate to thermodynamic and kinetic factors and their influence on anticancer action. In this dissertation the properties of novel platinum(II) complexes of a bidentate ligand having an aromatic nitrogen-donor atom in combination with a thioethereal sulfur atom capable of forming a five membered ring with platinum(II) were studied. The general structure of the (NS) -ligands used were N-alkyl-2-methylthioalkyl imidazole. Alkyl groups used were methyl, ethyl and propyl. Although amine complexes of platinum have been extensively studied there are some new aspects of these that are worthwhile investigating. In this dissertation amines having planar attachments which will be at an angle with the coordination plane viz. benzylamine and amines having cyclic aliphatic groups namely cyclopropyl and cyclohexyl were investigated. Some of the (NS) - and amineplatinum(II) complexes were oxidised to their mononitroplatinum(IV) analogues . The motivation for the synthesis of these complexes was the greater kinetic stability of platinum(IV) and recent research has shown that a specific type of platinum(IV) compound shows suitable properties as an anticancer agent. These complexes were characterised by a variety of spectral means (IR, NMR, mass spectroscopy) as well as elemental analysis, solubility determinations, thermal analysis (TGA), ionization studies and finally their anticancer behaviour towards three different cell lines(Hela, MCF 7, Ht29) and in this process they were compared to the behaviour of cisplatin as a reference. A few have shown promising anticancer behaviour.

Gli stili APA, Harvard, Vancouver, ISO e altri

50

Haskard, Carolyn Anne. "Multiple recognition by modified cyclodextrins". Title page, contents and abstract only, 1996. http://web4.library.adelaide.edu.au/theses/09PH/09phh349.pdf.

Testo completo

Abstract (sommario):

Copy of author's previously published article inserted. Includes bibliographies This thesis studies the B-cyclodextrins which are modified at the primary rim to incorporate an additional coordination or hydrophobic recognition site. The natural organic host, cyclodextrin and its chemically modified derivatives, are utilised as hosts for the inclusion of a range of guests. The study contributes to understanding the fundamental factors influencing selectivity of binding and the stability of the complexes formed when a guest is bound essentially at two recognition sites.

Gli stili APA, Harvard, Vancouver, ISO e altri

Tesi sul tema "Complex compounds"

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili