Tesi sul tema "Formation of supramolecules"
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WENG, WENGUI. "GEL FORMATION OF METALLO-SUPRAMOLECULAR POLYMERS". Case Western Reserve University School of Graduate Studies / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=case1194555000.
Testo completoPirinccioglu, Necmettin. "Modification of reactivity by supramolecular complex formation". Thesis, University of Kent, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309749.
Testo completoPark, Jong Seung. "Studies on Inclusion Complexes of Cyclodextrin and Dyes; I.Synthesis and Properties of Dye Rotaxanes, II. Formation of Anisotropic Supremolecules". Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7482.
Testo completoRussell, James Christopher. "Supramolecular network formation from solution-based deposition techniques". Thesis, University of Nottingham, 2011. http://eprints.nottingham.ac.uk/13080/.
Testo completoDel, Valle Ian M. "Formation of Functionalized Supramolecular Metallo-organic Oligomers with Cucurbituril". Ohio University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1449233679.
Testo completoBatchelor, E. "Acid:base Co-crystal formation in crystal engineering and supramolecular design". Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.596460.
Testo completoGirardeau, Tom Edwards. "Formation, morphology, and dynamics of poly(ethylene glycol)/α-cyclodextrin polyrotaxanes". Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/30545.
Testo completoSaulzet, Sylvie Isabelle. "Formation of supramolecular structures in aqueous solution and their interactions with surfaces". Thesis, University of York, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301149.
Testo completoChen, Junpeng. "Enzymatic formation of supramolecular hydrogels based on self-assembly of DNA derivatives". Waltham, Mass. : Brandeis University, 2009. http://dcoll.brandeis.edu/handle/10192/23323.
Testo completoDippenaar, Alwyn Bernard. "Hydrate formation in pharmaceutically relevant salts". Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95979.
Testo completoENGLISH ABSTRACT: A theoretical and experimental study was performed in order to identify factors that influence the propensity of compounds containing anionic functional groups that are commonly found on pharmaceutical drug compounds to form hydrates. A Cambridge Structural Database (CSD) survey was initially undertaken to determine the propensity of different pharmaceutically acceptable anions to form hydrates. The results showed that hydrate formation will take place more regularly when the polarity of the functional group increases. Furthermore, if the charge distribution is very concentrated over the polar groups, hydrate formation will occur more readily. This observation was further investigated by performing a series of potential energy surface (PES) scans for the hydrogen bond (H-bond) in the structure of N-(aminoiminomethyl)-N-methylglycine monohydrate (creatine monohydrate) with various Density Functional Theory (DFT) and Wave Functional Theory (WFT) methods. WFT is often also referred to as ab initio, which refers to the construction of the wave function from first principles when this theory is applied. The scans revealed that several strong and directional H-bonds with different geometrical parameters between the carboxylate group and the water molecule are possible, which suggests that the H-bond plays an important role in driving the formation of pharmaceutical hydrates. A total of 44 hydrate structures were identified that have pharmaceutically acceptable functional groups. Optimisations in the gas phase and in an implicit solvent polarisable continuum solvent model with a variety of solvents showed that there is a significant dependence of the H-bond interaction energy on the anionic group as well as the steric density of surrounding substituents. It was found that the M06-2X method utilising the 6-311++G(d,p) basis set outperformed the other methods that were tested when compared to optimisations performed with the benchmark MP2/aug-cc-pVTZ level of theory. Furthermore, the strength of the H-bond was measured in the 44 experimentally determined structures by using a total of five generalized gradient approximation (GGA) methods, of which two methods contained the DFT-D3 correction. The results of these DFT methods were subsequently compared to results obtained at the benchmark MP2/aug-cc-pVTZ level of theory. The M06-2X method was identified as the most economical method to calculate H-bond energies. It was also found that the H-bond interaction energy shows a substantial dependence on the electrostatic environment. This was observed by a significant decrease in H-bond strength as the relative permittivity of the solvent increases. The effect of steric density on the H-bond interaction energy was investigated by performing hydrogen bond propensity calculations. These values were then compared to the interaction energies of each structure and the results showed that the presence of large bulky substituents can lead to an increase in bond energy by forcing the anionic functional group closer to the water molecule. Contrastingly, the bulky group can also push the anionic group away from the water molecule and result in a decrease in bond energy. Approximate values for the amount of stabilisation offered to the H-bonding system by the surrounding crystalline environment were calculated by optimising the H-bond geometrical parameters of selected compounds with a combination of the M06-2X and MP2 methods utilising the 6-311++G(d,p) basis set. The H-bond interaction energies were then calculated at the M06-2X/6-311++G(d,p) level of theory and compared to the H-bond interaction energies in geometries that have been fully optimised. After these energies were compared and the crystal packing of each structure was investigated, it was found that the packing of some structures within the crystalline environment limits the number of H-bonds that can be formed between the water and the compound of interest. Full optimisation calculations result in structures with cooperative stabilisation, such that more than one H-bond is found between the two fragments. The effect of substituents on H-bond interaction energy was investigated by the addition of six electron-donating and electron-withdrawing groups on four aromatic compounds with different anionic functional groups, namely carboxylate, nitrogen dioxide, sulfonate and phosphonate. It should also be mentioned that the nitrogen dioxide is not an anionic functional group, but it was included as it is a neutral radical that often forms hydrogen bonds. A total of 80 structures were optimised with a combination of the M06-2X and MP2 methods utilising the 6-311++G(d,p) basis set. This was followed by counterpoise corrected single point calculations at the M06-2X/6-311++G(d,p) level of theory. The results showed that the H-bond interaction energy bears no relationship to the inductive strength or the inductive ability of the substituents, but rather the ability of these substituents to rotate the anionic functional group and allow cooperative stabilisation of the H-bond. Furthermore, AIM analysis was performed for the substituted H-bonded aromatic structure. The results showed that electron-donating groups that are placed at the para position yield stronger H-bonds, which is once again accompanied by cooperative stabilisation. Electron-withdrawing groups with sufficient inductive effects can result in a weaker H-bond when placed at the meta position. The effect of water activity (aw) on the hydrate crystal formation was investigated experimentally by performing a series of crystallisations in various solvent mixtures. These mixtures consisted of water mixed with acetone, ethanol and ethyl acetate. A total of three organic acids were used in crystal formation, namely pyridine-4-carboxylic acid (isonicotinic acid), N-amino-iminomethyl-N-methylglycine (creatine) and benzene-1,3,5-tricarboxylic acid. It was found that water activity affects the formation of the hydrate as well as the anhydrous product. Additionally, nucleation and super saturation plays a large role in crystal formation and can serve as an effective technique when the formation of crystals of an appropriate shape and size is required for further analysis.
AFRIKAANSE OPSOMMING: 'n Teoretiese en eksperimentele studie was uitgevoer om faktore te identifiseer wat die geneigdheid van verbindings met anioniese funksionele groepe wat algemeen gevind word op farmaseutiese dwelm verbindings om die hidraat produk te vorm, affekteer. 'n Opname van strukture in die Cambridge Strukturele Databasis (CSD) is onderneem om die geneigdheid van verskillende farmaseutiese aanvaarbare anione om hidrate te vorm te bepaal. Die resultate het getoon dat hidraatvorming meer gereeld plaasvind indien die polariteit van die funksionele groepe toeneem. Verder is daar ook opgemerk dat 'n gekonsentreerde ladingsverspreiding op die polêre groepe ook tot 'n toename in hidraat vorming sal lei. Hierdie waarneming is verder ondersoek deur 'n reeks potensiële energie oppervlak (PES) skanderings van die waterstof binding (H-binding) vir die struktuur van N-amino-iminometiel-N-metielglisien monohidraat (kreatien monohidraat) met verskeie Digtheids-Funksionele Teorie (DFT) en Golffunksie Teorie (WFT) metodes uit te voer. Die skanderings het getoon dat verskeie sterk, gerigte H-bindings met verskillende geometriese parameters tussen die karboksilaatgroep en die watermolekule kan vorm. Hierdie bevindinge lê klem op die belangrike rol wat H-bindings in die vorming van farmaseutiese koolhidrate speel. 'n Totaal van 44 hidraat strukture met farmaseutiese aanvaarbare funksionele groepe was geïdentifiseer. Optimaliserings is in die gas fase asook in 'n implisiete kontinuum polariseerbare oplosmiddel model met 'n verskeidenheid oplosmiddels uitgevoer. Die resultate het 'n beduidende afhanklikheid van die H-binding interaksie-energie op die anioniese groep asook die steriese afkskerming van omringende groepe getoon. Daar is bepaal dat die M06-2X metode wat saam met die 6-311++G(d,p) basisstel die mees akkuraatste resultate gelewer het in vergelyking met die ander DFT metodes asook die MP2/aug-cc-pVTZ maatstaf. Die H-binding se sterkte is vir hierdie strukture bereken deur vyf GGA metodes te gebruik, waarvan twee metodes van die DFT-D3 korreksie gebruik maak. Die resultate van die berekeninge met hierdie DFT metodes is daarna vergelyk met resultate verkry met die MP2/aug-cc-pVTZ maatstaf. Daar is gevolglik bepaal dat die M06-2X metode die mees ekonomiese metode is om H-binding energië te bereken. Die H-binding interaksie energie toon 'n aansienlike afhanklikheid op die diëlektriese konstante van die oplosmiddel aan. Hierdie waarneming is op grond van 'n beduidende afname in die H-binding interaksie-energie indien die relatiewe permittiwiteit van die oplosmiddel verhoog word gemaak. Die effek van steriese digtheid is ondersoek deur waterstofbindinggeneigdheid waardes te bereken. Hierdie waardes is met die interaksie-energië van elke struktuur vergelyk. Die resultate dui daarop dat steries digte groepe tot 'n toename in interaksie energie kan lei wanneer die anioniese funksionele groep nader aan die water molekule gestoot word. Verder is dit ook moontlik vir hierdie steries digte groepe om die anioniese groep weg van die water molekule te stoot en gevolglik 'n afname in interaksie energie te veroorsaak. Benaderde waardes vir die hoeveelheid stabilisering wat die omringende kristallyne omgewing aan die H-binding bied is bereken deur die H-binding geometriese parameters van geselekteerde verbindings met die M06-2X en MP2 metodes en die 6-311++G (d,p) basisstel te optimaliseer. Die H-binding interaksie-energië is gevolglik by die M06-2X/6-311++G(d,p) vlak van teorie bereken en met die H-binding energië in strukture wat volledige optimaliseer is vergelyk. Nadat hierdie waardes vergelyk is, is daar gevind dat die pakking van strukture in the kristallyne omgewing verhoed dat sekere H-bindings tussen die water molekule en die verbinding van belang kan vorm. Strukture wat volledig optimaliseer is, lei tot strukture wat in staat is om koöperatiewe stabilisering te ondergaan. Koöperatiewe stabilisering word gekenmerk deur die vorming van meer as een H-binding tussen twee fragmente. Die effek van substituente op die H-binding interaksie energie is ondersoek deur die bevoeging van ses elektrondonor- en elektronontrekkendegroepe op vier aromatiese verbindings, naamlike die karboksilaatgroep , stikstofdioksied , sulfonaat en fosfonaat. Dit moet ook genoem word dat stikstofdioksied nie 'n anioniese funksionele groep is nie, maar dit was wel ingesluit omdat dit ‘n neutrale radikaal groep is wat dikwels waterstofbindings vorm. 'n Totaal van 80 strukture optimiserings was uitgevoer met 'n kombinasie van die M06-2X en MP2 metodes wat gebruik maak van die 6-311++G(d,p) basisstel. Dit is gevolg deur interaksie-energie berekeninge op die M06-2X/6-311++G(d,p) vlak van teorie. Die resultate het getoon dat daar geen verband tussen die induktiewe vermoë van die substituente en die sterkte van die H-binding is nie, dit is eerder die vermoë van hierdie substituente om die anioniese funksionele groep te laat roteer wat toelaat dat koöperatiewe stabilisering van die H-binding kan geskied. Die AIM analise is op 'n gesubstitueerde H-binding struktuur toegepas. Die resultate het getoon dat elektrondonorgroepe wat by die para posisie geplaas word tot sterker H-bindings sal lei, wat weereens met koöperatiewe stabilisering vergesel word. Elektrononttrekkendegroepe met sterk induktiewe effekte kan tot 'n swakker H-binding lei indien hulle by die meta posisie geplaas word. Die effek van water aktiwiteit (𝑎w) op hidraatkristalvorming is deur die uitvoering van 'n reeks kristallisasies in verskeie oplosmiddelmengsels ondersoek. Hierdie oplosmiddel mengsels bestaan uit water met asetoon, etanol of etielasetaat gemeng. Kristallisasies is vir drie organiese sure, naamlik piridien-4-karboksielsuur, N-amino-iminometiel-N-metielglisien monohidraat en 1,3,5-benseen tri-karboksielsuur uitgevoer. Daar is gevind dat water aktiwiteit 'n invloed op die vorming van die hidraat en watervrye produkte kan hê. Daarbenewens, speel water aktiwiteit 'n belangrike rol in die nukleasie fase van kristalvorming en kan as 'n effektiewe tegniek dien om kristalle van 'n toepaslike vorm en grootte vir verdere analise te verkry.
Jones, Samuel Thomas. "Supramolecular self-assembly of noble metal nanoparticles via cucurbit(8)uril ternary complex formation". Thesis, University of Cambridge, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.648835.
Testo completoWahl, Helene. "Investigation into co-crystal formation with cyclophosphazenes". Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/19939.
Testo completoENGLISH ABSTRACT: This study aimed to combine the principles of crystal engineering with the properties of cyclotriphosphazene derivatives to construct supramolecular assemblies in the solid state. The ease with which the chloro substituents on cyclotriphosphazenes can be replaced makes them ideal candidates for this study. The substituents were chosen for their ability to form either hydrogen bonding interactions or halogen bonding interactions in the solid state. The cyclotriphosphazene derivatives were co-crystallised with various small organic molecules with complementary functional groups, as well as with other cyclophosphazene derivatives. The aim was to form co-crystals or solvates with these cyclophosphazene derivatives as co-crystals contain a wealth of information regarding the forces governing the aggregation of molecules in the solid state. Cyclotriphosphazenes, with their array of substituents, could broaden the range of potential interactions governing crystalline assembly. Fifteen cyclotriphosphazene derivatives were synthesised and characterised in this study. The novel crystal structures of two cyclotriphosphazene derivatives have been elucidated by single crystal X-ray diffraction. These are 2,2-bis(4-formylphenoxy)-4,4,6,6-bis[spiro(2',2"-dioxy-1',1"-biphenylyl)]cyclotriphosphazene and hexakis(4-cyano-phenoxy)cyclotriphosphazene. In the course of this study two novel polymorphs of hexakis(4-fluorophenoxy)cyclotri-phosphazene were identified and studied. The novel triclinic form undergoes an irreversible transformation to the previously reported monoclinic phase at high temperatures. The reported monoclinic phase, however, transforms to a monoclinic C phase in a single-crystal to single-crystal fashion. It is also suspected that this phase transformation is in fact reversible on cooling of the crystal to temperatures below -45 °C. One novel co-crystal structure of hexakis(4-pyridyloxy)cyclotriphosphazene with terephthalic acid was identified and characterised. However, analysis of the Cambridge Structural Database indicates that co-crystal formation with cyclophosphazenes is not a commonly occurring phenomenon. This leads to the conclusion that cyclotriphosphazenes can be used in crystal engineering as supramolecular building blocks, but their shape and size tend to inhibit the formation of co-crystals. Therefore co-crystal formers have to be chosen with great care.
AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die beginsels van kristalingenieurswese te kombineer met die eienskappe van siklotrifosfaseen afgeleides om sodoende supramolekulêre versamelings in die vastetoestand te bou. Die gemak waarmee die chloor substituente op die siklotrifosfaseenring vervang kan word, maak hierdie molekules ideaal vir hierdie studie. Die substituente is gekies op grond van hul potensiaal om waterstofbindings of intermolekulêre halogeenbindings in die vastetoestand te vorm. Ko-kristallisasie eksperimente is met die siklotrifosfaseen afgeleides en verskeie klein organiese molekules met komplementêre funksionele groepe uitgevoer, asook tussen die verskeie siklotrifosfaseen afgeleides met mekaar. Die doel was om mede-kristalle of solvate met hierdie siklotrifosfaseen afgeleides te vorm aangesien mede-kristalle ‘n magdom inligting bevat rakende die kragte wat die versameling van molekules in die vaste fase beheer. Die siklotrifosfaseen afgeleides wat ‘n wye verskeidenheid substituente kan dra, kan hierdeur die moontlike intermolekulêre interaksies wat die versameling in die kristallyne vaste fase beheer verbreed. In hierdie studie is vyftien siklotrifosfaseen afgeleides gesintetiseer en gekarakteriseer. Die voorheen onbekende kristalstrukture van twee siklotrifosfaseen afgeleides is in hierdie studie geïdentifiseer, naamlik 2,2-bis(4-formielfenoksie)-4,4,6,6-bis[spiro(2',2"-dioksie-1',1"-bifeniliel)]siklotrifosfaseen en heksa(4-sianofenoksie)siklotrifosfaseen. Die strukture is bepaal deur enkelkristal X-straaldiffraksie. In die loop van hierdie studie is twee voorheen onbekende polimorfs van heksa(4-fluorofenoksie)siklotrifosfaseen geïdentifiseer en bestudeer. Die nuwe trikliniese vorm ondergaan ‘n onomkeerbare faseverandering na die monokliniese vorm by hoë temperature. Die bekende monokliniese P fase ondergaan egter ‘n verdere faseverandering na ‘n monokliniese C fase. Hierdie geskied as ‘n enkel-kristal na ‘n enkel-kristal faseverandering. Daar word ook gespekuleer dat hierdie spesifieke faseverandering wel omkeerbaar is indien die kristal na -45 °C afgekoel word. Een nuwe mede-kristal tussen heksa(4-pyridieloksie)sikotrifosfaseen en 1,3-dibensoësuur is in hierdie studie geïdentifiseer en gekarakteriseer. ‘n Analise van die Cambridge Strukturele Databasis het egter aangedui dat die vorming van mede-kristalle nie ‘n alledaagse verskynsel is in sikotrifosfaseen afgeleides nie. Dit lei tot die gevolgtrekking dat sikotrifosfaseen molekules wel in kristalingenieurswese gebruik kan word as supramolekulêre boustene, maar dat die vorm en grootte van die molekules die kristallisering van mede-kristalle verhoed. Dus moet die molekules wat saam met die siklotrifosfaseen molekules gekristalliseer wil word, goed deurdink word.
Orton, James Benjamin. "A systematic study of the formation of pyridine-based supramolecular assemblies in the solid-state". Thesis, University of Southampton, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438690.
Testo completoBeck, John Benjamin. "Using the Metal-Ligand Interaction to Construct Complex Supramolecular Polymer Architectures". Case Western Reserve University School of Graduate Studies / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=case1112815582.
Testo completoRossi-Gendron, Caroline. "Dynamic DNA origamis as isothermal supramolecular machines : melting dynamics, photocontrol and isothermal folding". Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS522.
Testo completoDNA origamis and Single Stranded Tiles (SST) appear to be two of the most promising components of the DNA nanotechnology field in terms of possible designs and applications. In this thesis, we explored the thermodynamic and kinetic aspects underlying DNA nanostructures formation as well as new practical ways to build dynamic programmable nano-objects. Notably, the study of the formation process evidenced the unnecessary presence of magnesium ions or buffering molecules in the medium, and new formation conditions have been described. The melting process triggered by temperature elevation was characterised using a new quantified gel electrophoresis method evidencing for the first time a non-monotonous behaviour and calling for a new definition of DNA origami melting temperature. Both formation and melting process were furthermore demonstrated to be controllable by light using AzoDiGua, a photosensitive DNA intercalator previously developed by our group. This allowed us to observe for the first time a light-controlled hybridisation / dehybridisation process within individual origamis at constant temperature and thus achieve a controlled motion at the nanoscale. We also established an original method for the isothermal formation of DNA origamis and SST at constant room temperature and without the presence of any denaturating agent. This allowed us to observe for the first time and in situ the isothermal folding of individual origamis, thus evidencing that origamis can reach their final equilibrium shape following a variety of folding pathways
Park, Jong Seung. "Studies on inclusion complexes of cyclodextrin and dyes I. Synthesis and properties of dye rotaxanes, II. Formation of anisotropic supremolecules /". Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-08262005-092849/.
Testo completoSrinivasarao, Mohan, Committee Chair ; Bunz, Uwe, Committee Co-Chair ; Griffin, Anselm, Committee Member ; Tolbert, Laren, Committee Member ; Park, Jung, Committee Member ; Beckham, Haskell, Committee Member. Includes bibliographical references.
Zhang, Ruimeng. "New Insight into Supramolecular Structure Formation of Polyhedral Oligomeric Silsequioxane (POSS) based ABn Type Giant Shape Amphiphiles: Linker’s Effects". University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1460344631.
Testo completoColazzo, Luciano. "On-Surface Supramolecular Networks: Structure and Dynamics of Formation in Ultra-High Vacuum and at the Solid/Liquid Interface". Doctoral thesis, Università degli studi di Padova, 2017. http://hdl.handle.net/11577/3422397.
Testo completoLa chimica supra-molecolare di superficie ha permesso la produzione di numerose nanostrutture tramite l'utilizzo di protocolli di sintesi innovativi. In questo modo si sono ottenuti, tramite controllo strutturale a livello atomico e molecolare, numerosi materiali a ridotta dimensionalità. L'applicazione di tali scoperte si sviluppa nell'ambito della ricerca relativa alla catalisi, all'elettronica organica, alla funzionalizzazione e alla sensibilizzazione della superfici. Poiché esistono diversi approcci per per la produzione di tali strutture, la ricerca ha spinto i propri interessi verso la nano-fabbricazione di materiali per ottenerne, sfruttando varie tecniche, di innovativi, più stabili ed efficienti. La fotochimica di superficie in questo senso, permette di ottenere materiali molto complessi ed inoltre permette di capire i fenomeni alla base dei processi di sintesi indotta dalla luce, che ad oggi, non sono del tutto semplici da interpretare. La microscopia a scansione di tunneling (STM) fornisce l'opportuna risoluzione spaziale per questo tipo di studi, i cui principi sono ancora oggi oggetto di dibattito.
Chernova, Ekaterina. "Synthesis of new [1111]metacyclophane ligands for the formation of molecular coordination networks". Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAF043/document.
Testo completoIn terms of supramolecular chemistry and molecular tectonics,[1111]metacyclophanes are attractive compounds for the preparation and study of molecular networks since the particular feature of these compounds is determined by exceptional stability of the 1,3-Alternate conformation of their molecular platform due to the steric hindrance between the orto-methyl groups of aryl rings. Such rigid type of molecular scaffold both with presence of terminal binding sites is considered as a very suitable molecular building block for formation of different type molecular networks using primarily coordination and H-bonding. Through this work we investigated the role of the nature of the coordinating sites grafted on the metacyclophane macrocyclic backbone in order to enhance their ability to form coordination networks in the crystalline phase and the supramolecular systems in solution, a series of new [1111]metacyclophanes have been synthesized and characterized in solution and in the solid state. Their propensity to bind different metal cations in the crystalline phase as well as complexes in solution have been studied
Busseau, Antoine. "Synthèse et caractérisations de nouveaux penta(organo)[60]fullerènes pour la formation d’assemblages supramoléculaires". Thesis, Angers, 2017. http://www.theses.fr/2017ANGE0033/document.
Testo completoThe unique structure and properties of fullerenes have attracted wide interest especially in electronic and optoelectronic fields. In this context, a variety of mono-and poly-fullerene adducts have been described for theirs interest in the development of new complex materials and supramolecular polymers. Here, we present the synthesis and studies of new donor-acceptor supramolecular polymers based on penta(organo)[60]fullerenes. The perfect regioselectivity of the [60]fullerene pentafunctionalization reaction has provided us a singular conical structure formed by five ethynylaryl fragments. To this structure different electro and/or photoactive fragments (tetrathiafulvalene or zinc-porphyrin) were covalently linked using five simultaneous 1,3-dipolar cycloaddition reactions. The formed host-cavity together with the donor-acceptor properties of these system allow their assembly by supramolecular interactions. We have realized the synthesis of these penta(organo)[60]fullerenes as new donor-acceptor materials and the studies of their remarkable supramolecular arrangement in solution and solid state
Dupont-Gervais, Annick. "Etude de supermolecules par spectrometrie de masse en mode d'ionisation electrospray. Suivi de la formation d'edifices supramoleculaires en solution". Université Louis Pasteur (Strasbourg) (1971-2008), 1996. http://www.theses.fr/1996STR13062.
Testo completoAfsari, Mamaghani Sepideh. "The Formation of Two Dimensional Supramolecular Structures and Their Use in Studying Charge Transport at the Single Molecule Level at the Liquid-Solid Interface". Diss., Temple University Libraries, 2015. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/350915.
Testo completoPh.D.
Understanding charge transport through molecular junctions and factors affecting the conductivity at the single molecule level is the first step in designing functional electronic devices using individual molecules. A variety of methods have been developed to fabricate metal-molecule-metal junctions in order to evaluate Single Molecule Conductance (SMC). Single molecule junctions usually are formed by wiring a molecule between two metal electrodes via anchoring groups that provide efficient electronic coupling and bind the organic molecular backbone to the metal electrodes. We demonstrated a novel strategy to fabricate single molecule junctions by employing the stabilization provided by the long range ordered structure of the molecules on the surface. The templates formed by the ordered molecular adlayer immobilize the molecule on the electrode surface and facilitate conductance measurements of single molecule junctions with controlled molecular orientation. This strategy enables the construction of orientation-controlled single molecule junctions, with molecules lacking proper anchoring groups that cannot be formed via conventional SMC methods. Utilizing Scanning Tunneling Microscopy (STM) imaging and STM break junction (STM-BJ) techniques combined, we employed the molecular assembly of mesitylene to create highly conductive molecular junctions with controlled orientation of benzene ring perpendicular to the STM tip as the electrode. The long range ordered structure of mesitylene molecules imaged using STM, supports the hypothesis that mesitylene is initially adsorbed on the Au(111) with the benzene ring lying flat on the surface and perpendicular to the Au tip. Thus, long range ordered structure of mesitylene facilitates formation of Au-π-Au junctions. Mesitylene molecules do not have standard anchoring groups providing enough contact to the gold electrode and the only assumable geometry for the molecules in the junction is via direct contact between Au and the π system of the benzene ring in mesitylene. SMC measurements for Au/mesitylene/Au junctions results in a molecular conductance value around 0.125Go, two orders of magnitude higher than the measured conductance of a benzene ring connected via anchoring groups. We attributed this conductance peak to charge transport perpendicular to the benzene ring due to direct coupling between the π system and the gold electrode that happens in planar orientation. The conductance we measured for planar orientation of benzene ring is two order of magnitude larger than conductance of junctions formed with benzene derivatives with conventional linkers. Thus, altering the orientation of a single benzene-containing molecule between the two electrodes from planar orientation to the upright attached via the linkers, results in altering the conductivity in a large order. Based on these findings, by utilizing STM imaging and STM-BJ in an electrochemical environment including potential induced self-assembly formation of terephthalic acid, we designed an electrochemical single molecule switch. Terephthalic acid forms large domains of ordered structure on negatively charged Au(111) surface under negative electrochemical surface potentials with the benzene ring lying flat on the surface due to hydrogen bonding between carboxylic acid groups of neighboring molecules. Formation of long range ordered structure facilitates direct contact between the π system of the benzene ring and the gold electrodes resulting in the conductance peak. On positively charged Au(111), deprotonation of carboxylic acid groups leads to absence of long range ordered structure of molecules with planar orientation and absence of the conductance peak. In this case alternating the surface (electrode) potential from negative to positive charge densities induces a transition in the adlayer structure on the surface and switches conductance value. Hence, electrochemical surface potential can, in principle, be employed as an external stimulus to switch single molecule arrangement on the surface and the conductance in the junction. The observation of conductance switching due to molecule’s arrangement in the junction lead to the hypothesis that for any benzene derivative, an orientation-dependent conductance in the junction due to the contact geometry (i.e. electrode-anchoring groups versus direct electrode-π contact) should be expected. Conventional techniques in fabricating single molecule junctions enable accessing charge transport along only one direction, i.e., between two anchoring groups. However, molecules such as benzene derivatives are anisotropic objects and we are able to measure an orientation-dependent conductance. In order to systematically study anisotropic conductivity at single molecule level, we need to measure the conductance in different and well-controlled orientations of single molecules in the junction. We employed the same EC-STM-BJ set up for SMC measurements and utilize electrochemical potential of the substrate (electrode) as the tuning source to variate the orientation of the single molecule in the junction. We investigated single molecule conductance of the benzene rings with carboxylic acid functional groups in two orientations: one with the benzene ring bridging between two electrodes using carboxylic acids as anchoring groups (upright); and one with the molecule lying flat on the substrate perpendicular to the STM tip (planar). Physisorption of these species on the Au (111) single crystal electrode surface at negative electrochemical potentials results in an ordered structure with the benzene ring in a planar orientation. Positive electrochemical potentials cause formation of the ordered structure with molecules standing upright due to coordination of a deprotonated carboxyl groups to the electrode surface. Thus, formation of the single molecule junction and consequently conductivity measurements is facilitated in two directions for the same molecule and anisotropic conductivity can be studied. In engineering well-ordered two-dimensional (2-D) molecular structures with controlled assembly of molecular species, pH can be employed as another tuning source for the molecular structures and adsorption in experiments conducted in aqueous solutions. Based on simple chemical principles, amine (NH2) groups are hydrogen bond acceptors and donors. Amines are soluble in water and protonation results in protonated (NH3+) and unprotonated (NH2) amine groups in acidic and moderately acidic/neutral solutions, respectively. Thus, amines are suitable molecular building blocks for fabricating 2-D supramolecular structures where pH is employed as a knob to manipulate intermolecular hydrogen bonding leading to phase transitions. We investigated pH induced structural changes in the 1,3,5–triaminobenzene (TAB) monolayer and the formation/disruption of hydrogen bonds between neighboring molecules. Our STM images indicate that in the concentrated acidic solution, the protonated amine groups of TAB are not able to form H-bonds and long range ordered structure of TAB does not form on the Au(111) surface. However, in moderately acidic solution (pH ~ 5.5) at room temperature, protonation on the ring carbon atom generates species capable of forming H-bonds leading to the formation of the long range ordered structures of TAB molecules. Utilizing EC-STM set up, we investigated the controllable fabrication of a TAB 2-D supramolecular structure based on amine-amine hydrogen bonding and effect of pH in formation of ordered/disordered TAB network.
Temple University--Theses
Hussein, Fatima. "Formation de nanostructures organiques contrôlées par auto-assemblages supramoléculaires et réactions sur surface". Electronic Thesis or Diss., Aix-Marseille, 2022. http://www.theses.fr/2022AIXM0521.
Testo completoThe controlled formation of new objects at the nanoscale is an important challenge for the development of new materials and electronic devices. In this context, the objective of this thesis is to propose new strategies to control the formation of organic nanostructures on surfaces based on the concepts of supramolecular self-assembly and on-surface synthesis and investigate their properties. First, we studied by scanning tunneling microscopy (STM) at ambient conditions the control of the size of the domains formed at the liquid-solid interface on HOPG from a bimolecular solution of trimesic acid (TMA) and benzoic acid (BZA). The results show that the formation of the domains is very sensitive to the stoichiometry ratio between the two molecules and a fine-tuning of this latter is required. Then, we studied the polymerization of 1,4-di(thiophen-2-yl)benzene (DTB) on Cu(111) under ultra-high vacuum (UHV) by STM and photoelectron spectroscopy (XPS), supplemented by non-contact atomic force microscopy (nc-AFM) and theoretical modelling based on the density functional theory (DFT). The results show the formation of unsaturated hydrocarbon chains based on C-S activation. Finally, we demonstrated by STM and XPS under UHV that the use of the bifunctional chiral precursor (R)-6-bromo-3-phenyl-2,3-dihydro-1H-inden-1-one (BrPhINDO) leads to the formation of different covalently bonded structures on Cu(111) with chiral inversion inducing partial racemization
Larpent, Patrick. "Tectonique moléculaire : conception et formation de polymères de coordination chiraux". Thesis, Strasbourg, 2013. http://www.theses.fr/2013STRAF044/document.
Testo completoThe synthesis and the use of porous chiral coordination polymers for enantioselective processes are of current interest and prime importance in chemistry. These crystalline materials are mainly obtained by combinations of well-designed organic tectons and properly chosen metallic components. This thesis deals with the synthesis of organic chiral building blocks and their combinations with a variety of metallic salts leading to chiral coordination networks. In a first part, the use of tectons bearing neutral coordinating sites is described. Homochiral cuboid architectures displaying monodimensional channels are presented. In the second part, mono- and bi-dimensional networks of various geometries are described. In some cases, within crystals, interactions lower in energy than the coordination bond are observed and are responsible for the formation of molecular networks of higher dimensionality. Finally, the use of organic tectons displaying charged interaction sites is presented. Their combination with metallatectons under thermal treatments affords robust tridimensional homochiralarchitectures displaying cavities. These materials are interesting candidates for enantioselective recognition and separation. Their gas adsorption propensity (N2 and CO2) is briefly discussed
Löffler, Susanne. "Host-Guest Chemistry of Acridone-based Coordiantion Cages". Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2018. http://hdl.handle.net/11858/00-1735-0000-002E-E415-6.
Testo completoEdler, Karen Jean. "Template Induction of Supramolecular Structure:". Phd thesis, 1997. http://hdl.handle.net/1885/7458.
Testo completoTsai, Meng-Shiue, e 蔡孟學. "Investigating of Intermolecular Fluorophobic and Pt-Pt Interactions on Supramolecular Gel Formation". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/89672122536791039520.
Testo completo國立中央大學
化學學系
101
A series of supramolecular gelators, DN143, DX23, DX97,DX101 and DX47, based on anthracene or pyrene with perfluoroalkyl chain pyridine-2,6-dicarboxamides has been synthesized. All gelators show excellent gelation ability in many organic solvents. We have found that the presence of the perfluoroalkyl chains as well as the Pt(II) metal centers both contribute to the gel formation and have great effects on their resulting physical properties. A variety of spectroscopic methods have been applied to identify the intermolecular interactions upon gel formation and explore the photophysical properties. The primary driving forces for the gel formation are intermolecular hydrogen bonding, aromatic pi-pi, and C-H•••pi interactions. The supramolecular aggregates in these organogels are considered to be the J-type aggregation. SEM and TEM morphologies on the xerogels reveal that the gelators self-assembled into fibers or spheres. Interestingly, helical fiber and sphere-like morphologies were observed for DN143 and DX97. In addition, DX97 and DX101 containing Pt(II) metal centers and perfluoroalkyl chains exhibit unique properties. DX97 exhibit dual emission with both fluorescence at 406 nm and strong phosphorescence at 655 nm. In contrast, DX101 does not show any detectable phosphorescence but only fluorescence at 436 nm. Photocycloaddition product was identified for DX101 in chlorinated solvent under UV irradiation. The mechanism for the observed photochemistry likely involves singlet oxygen and proceeds with free-radical pathways.
Bennett, James Lyle. "Assembly of a novel cavitand utilizing dynamic covalent bond formation". 2008. http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.17434.
Testo completoAdeoye, Oluwatomide. "Cyclodextrin supramolecular systems for oral antiretroviral drug delivery". Doctoral thesis, 2019. http://hdl.handle.net/10451/42258.
Testo completoSahoo, J. K., S. Roy, Nadeem Javid, K. Duncan, L. Aitken e R. V. Ulijn. "Pathway-dependent gold nanoparticle formation by biocatalytic self-assembly". 2017. http://hdl.handle.net/10454/13020.
Testo completoWe report on the use of non-equillibrium biocatalytic self-assembly and gelation to guide the reductive synthesis of gold nanoparticles. We show that biocatalytic rates simultaneously dictate supramolecular order and presentation of reductive phenols which in turn results in size control of nanoparticles that are formed.
BBSRC funding (BB/K007513/1); European Research Council under the European Union’s Seventh Framework Programme, ERC (Starting Grant EMERgE) grant agreement no. 258775.
Huang, Yen-Chung, e 黃彥中. "Synthesis of Iron-Sulfur Core Complexes and Arene Ruthenium(II) Complexes Containing Isocyanide Ligands and Their Application on the Supramolecular Formation". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/95556144088814791522.
Testo completo高雄醫學大學
醫藥暨應用化學系碩士班
104
The metal-containing supramolecular complexes are often using pyridine derivatives as a coordinated bridging spacer ligand. It is rare to see isocyanides as coordinated bridging spacer ligands in supramolecular complexes. In order to expand the metal-driven isocyanide bridging spacer supramolecular chemistry, a series of iron-sulfur core complexes containing isocyanide ligands were synthesized by self-assembly reaction between [Cp2Fe2(µ-SEt)2(1,4-CNC6H5NC)2(BF4)2] (4(BF4)2) and transition metal complexes. Except the iron-sulfur core complexes, the ruthenium complex [(p-cymene)RuCl2]2 (5) and [(p-cymene)RuCl(CO2)]2 (6) also selected as the building unit to react with diisocyanide ligands to form the new type of metal-containing supramolecular complexes. The formulation of all iron-sulfur core and ruthenium complexes were confirmed by NMR and IR spectroscopy as well as the ESI-Mass spectrometry. The electrochemical behaviors study of these iron-sulfur core containing ruthenium complexes were examined to understand their electronic communication involving the bridging isocyanide spacer ligands.
Levasseur-Grenon, Olivier Y. "Assemblage moléculaire régi par la formation de bifluorènes : vers la formation de réseaux organiques covalents retenus par des liaisons carbone-carbone". Thèse, 2014. http://hdl.handle.net/1866/11465.
Testo completoCovalent organic frameworks (COFs) are ordered two-dimensional and three-dimensional frameworks assembled only from light atoms in the first and second rows of the periodic table. These frameworks have shown properties that make them potentially useful in the storage of molecular guests, in catalysis and in separation. COFs are typically obtained by a final condensation reaction, which makes their crystallization difficult and leads to materials that are inhomogeneous and impossible to characterize in detail. The p-xylylenes of Thiele and Tschitschibabin are molecules that have attracted interest because of their structures and magnetic properties. Subsequently, Wittig demonstrated that replacing diphenylmethylene fragments in these structures by fluorenylidene units allowed their oligomerisation to form tetrameric structures. In our study, we have investigated the assembly of fluorenylidene derivatives to obtain COFs. First, a linear derivative similar to that obtained by Wittig was prepared to verify the feasibility of assembly from a spirobifluorenyl core. These compounds were found to oligomerise to form a tetramer, as expected as well as a hexamer. Both results have been rationalized by a study of the crystal structures by X-ray diffraction. The three-dimensional packing has also been analyzed. Subsequently, tetrahedral derivatives were synthesized to study the possibility of analogous assembly leading to COFs. A first derivative was found to remain in its quinoidal form rather than oligomerise and a second derivative resulted in a partially assembled dimer. The structure of the latter suggests that a linear polymer could be formed by a further reaction.
Nayak, Susanta Kumar. "Disorder, Polymorphism And Co-Crystal Formation In Molecular Crystals : An In-Depth Study In Terms Of Weak Intra- And Intermolecular Interactions". Thesis, 2010. https://etd.iisc.ac.in/handle/2005/1431.
Testo completoNayak, Susanta Kumar. "Disorder, Polymorphism And Co-Crystal Formation In Molecular Crystals : An In-Depth Study In Terms Of Weak Intra- And Intermolecular Interactions". Thesis, 2010. http://etd.iisc.ernet.in/handle/2005/1431.
Testo completoWang, Chun-Hsiang, e 王俊翔. "Synthesis of a New Metal-ion Responsive Azacrown Coumarin Containing Photoluminescent Polypeptide to Investigate the Metal Ions Induced Supramolecular Assembly Behaviors and the Feasibility as the Formation of Mercury Nanoparticle Template / Synthesis and Exploration of Pyridine Containing Polypeptides in the Catalytic Application". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/69q76g.
Testo completo國立臺灣大學
化學研究所
107
Forming supramolecular assemblies and controlling their behaviors via non-covalent interactions mimicking multi-functional materials have drawn much attention. Utilization of strong and directional interactions such as metal-ligand coordination can achieve spontaneous formation of selective, simple, and reversible supramolecular assemblies. However, it still remains a great challenge to monitor the underlying supramolecular assembly temporally. Herein, a new metal ion-responsive azacrown coumarin-conjugated photoluminescent polypeptide (ACCP) was designed and synthesized via in situ generated N-carboxyanhydride from the corresponding activated urethane monomer to exploit the metal ion-induced supramolecular assembly behaviors. After screening with various metal ions in either acetonitrile or chloroform, the results showed that ACCP˙Cu2+ exhibited blue emission in acetonitrile. However, ACCP dissolved in chloroform displayed strong fluorescence intensity enhancement only in the presence of either Hg2+ or Na+. In the combination of the absorption and the fluorescence profile, the morphologies of ACCP can be deduced. Notably, ACCP can also induce the formation of mercury nanoparticle. The morphologies of the mercury nanoparticle was 10 nm solid nanosphere stabilized by ACCP which was confirmed by transmission electron microscope. ACCP induced mercury nanoparticle was further used as the catalyst in Beckmann rearrangement. The preliminary results show that ACCP induced mercury nanoparticle was unable to catalyze the reaction due to the fact that the mercury nanoparticle was encapsulated compactly in the interior of the polymersome, rendering the mercury nanoparticles not accessible to the substrates. Further optimization of the reaction condition is required. Inspired by the ACCP induced mercury nanoparticle, polypeptide containing the pyridine ligands were designed and synthesized. Taking the advantage of the chirality in the polypeptide and the immobilization of the palladium via pyridine ligands, it is hoped to achieve good stereoselectivity in the synthesis of unnatural amino acid and the recover the palldium. A new synthetic strategy was developed to synthesize polymerizable monomer with the pyridine ligand to mitigate the contamination of the palladium needed to used in the original strategy. Based on this strategy, PPy-Lys, MPy-Lys, OPy-Lys, and Y-Lys were successfully synthesized, PPy-PLL and MPy-PLL were obtained in good yield with molecular weight around 8 kDa. PPy-PLL was further used as a ligand to C-H activation. The results revealed that PPy-PLL was unable to improve either yield or enantioselectivity. New ligands are required to achieve the C-H activation and high enantioselectivity.