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The synthesis and structure of C4 symmetric resorcinarenesMcIldowie, Matthew January 2007 (has links)
This study investigates methods for the synthesis and resolution of chiral resorcinarenes.The first direct synthesis of C4 dissymmetric resorcinarenes by the Lewis acid catalysed condensation of 3-alkoxyphenols and alkyl aldehydes was developed. The chirality of these novel resorcinarenes was demonstrated by nuclear magnetic resonance spectroscopy (n.m.r.) and enantioselective HPLC. The structure and physical properties of the new materials were characterised by several methods including X-ray crystallography.Resolution of the chiral resorcinarenes was achieved on a multi-gram scale by either formation of their diastereomeric camphorsulfonate esters or diastereomeric "amide" derivatives followed by flash chromatographic separation. The absolute configuration of one resorcinarene camphorsulfonate diastereomer was determined by X-ray crystallography and the stereochemistry of the related diastereomers assigned based on spectroscopic and chromatographic properties. Hydrolysis of the resolved resorcinarene camphorsulfonate diastereomers afforded the C4 symmetric resorcinarenes of known absolute stereochemistry. The absolute configuration of one resorcinarene "amide" diastereomer was also determined by X-ray crystallography.Functionalisation of the resorcinarene racemates with 2- and 3-picolyl ethers afforded a number of resorcinarene based pyridine ligands. The complexation behaviour of the ligands was examined and X-ray crystallographic data obtained for complexes with silver(I) and copper(II) salts.A significant proportion of the work described in this thesis has been published in four separate peer reviewed papers which have been attached as appendices 12-15.
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Two New Resorcinarenes: A Pyridine & Acetic Acid Ligand for Metal Coordination and a Deep-Cavity Nitroquinoxaline ResorcinareneVernetti, Samantha Sizemore 13 April 2006 (has links)
Functionalizing the upper rim of resorcinarene-based cavitands allows a variety of compounds to be synthesized from a single scaffold. Using the upper-rim moieties as ligands for a variety of transition metal ions further increases the versatility of this class of host compounds. A new resorcinarene-based molecule functionalized with four pyridine and acetic acid ligands has been successfully prepared to explore the properties of metal-assembled complexes. To synthesize this compound, tetra(bromomethyl)cavitand was reacted with N-(2-pyridylmethyl)-N-ethylacetate amine to give ethyl acetate pyridine resorcinarene. Hydrolysis of the ester gave acetic acid pyridine resorcinarene (APRes) in good yield. Complexes with Cu2+, Co2+, and Zn2+ are currently being investigated and characterized by MS and 1H and 13C NMR.
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Studies in the selective synthesis of bidentate resorcinarene ligandsKleinhans, Dewald Johannes 03 1900 (has links)
Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Resorcinarenes are macrocyclic products formed from the condensation of aldehydes (aliphatic or aromatic) and
resorcinol and have been used in a wide range of applications since their first synthesis. Applications include:
HPLC stationary phases for the separation of pyrimidine bases, racemic drugs and isomers, the selective
extractions of lanthanides and actinides, as molecular receptors, catalysis, NMR chiral shift agents, GC
separations and as starting materials for the synthesis of macrocyclic compounds (e.g. cavitands and carcerands)
to name but a few. The use of resorcinarenes in catalysis is still quite new and unexplored, while catalysis using
calix[4]arenes, a related macrocycle, has been widely studied. In this thesis it was attempted to synthesise a C2v
symmetric resorcinarene precursor that could be further functionalised to form distal bidentate ligands for
coordination to transition metals. These compounds would then ultimately be used in catalytic testing,
especially for Pd catalysed C-C bond formation.
A dibromo resorcinarene precursor was synthesised starting from resorcinarene, using methodology developed
by Shivanyuk. This molecule was functionalised with a small range of different electrophiles using lithium
halogen exchange methodology, although low yields were returned for the expected distal resorcinarene
compounds. Other methods of functionalisation of the resorcinarene, using an anionic ortho-Fries
rearrangement and the reduction of a dinitrile resorcinarene to amine and aldehyde functionalities proved
unsuccessful.
Using a dithioether resorcinarene a di-nuclear coordination compound was formed with Pd(II). This compound
was tested for catalytic activity with a Heck reaction, showing low yields for the coupling of styrene with bromobenzene. / AFRIKAANSE OPSOMMING: Resorsinarene is makrosikliese produkte wat gevorm word deur die kondensasie van aldehiede (alifaties of
aromaties) met resorsinol en word in ‘n verskeidenheid van toepassings gebruik sedert hulle eerste sintese.
Tipiese voorbeelde sluit in: stationêre fases vir die HPLC-skeiding van pirimidien-basisse, rasemiese
farmaseutiese middels en isomere, die selektiwe ekstraksie van lantaniede en aktiniede, molekulêre reseptore,
katalise, chirale verskuiwingsreagense vir KMR spektrometrie, GC-skeidings en as uitgangverbindings vir die
sintese van ander makrosikliese verbindings (bv. kavitande en karserande). Die gebruik van resorsinarene in
katalise is ’n splinternuwe onontginde veld. In teenstelling hiermee is calix[4]areen, ’n verwante makrosikliese
verbinding, baie meer bestudeer en vir katalise gebruik. Die doel van hierdie tesis was om ’n C2v simmetriese
uitgangstof te sintetiseer wat verder gefunksionaliseer kan word om distale, bidentate ligande vir koordinasie
met oorgangsmetale te lewer. Daar is beplan om die katalitiese eienskappe van die komplekse te toets, veral vir
Pd-gekataliseerde C–C-koppelings reaksies.
Deur gebruik te maak van ’n protokol wat deur Shivanyuk ontwikkel is, is ’n dibromo-resorsinareen
gesintetiseer uit resorsinareen. Verskillende elektrofiele is in ’n litium-halogeen uitruilreaksie gebruik om ’n
beperkte verskeidenheid nuwe ligande te sintetiseer wat verskillende funksionele groepe besit. Ongelukkig was
die opbrengste aan distale ligande baie laag en ander metodes is dus ook ondersoek om die funksionalisering te
bewerkstellig. ’n Anioniese orto-Fries herrangskikkingsreaksie en die reduksie van ’n dinitriel-resorsinareen om
amien- en aldehiedfunksies te lewer, was ook onsuksesvol.
Die reaksie tussen ‘n Pd(II) sout en ‘n ditioeter-gederivatiseerde resorsinareen het ‘n koordinasie verbinding met
twee metaalkerne gelewer. Hierdie kompleks is deur middel van ‘n Heck-koppelingsreaksie vir katalitiese
aktiwiteit getoets, maar het lae opbrengste gelewer in die koppeling van stireen en bromobenseen.
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Resorcinarenic phosphines and iminophosphoranes for catalysis : formation of capsular complexes / Phosphines et iminophosphoranes résorcinaréniques pour la catalyse : formation de complexes capsulairesChavagnan, Thierry 26 September 2016 (has links)
Ce mémoire est consacré à la synthèse et à l'étude de coordinats phosphorés originaux construits sur des résorcinarènes rigidifiés. Trois types de ligands ont été élaborés : 1) des phosphines tertiaires obtenues par ancrage de groupes –PPh2 sur des cycles aromatiques d'un résorcinarène générique. Celles-ci réagissent avec des espèces cationiques en formant des complexes chélate P,O résultant du clivage d'une liaison C–O localisée en ortho du cycle phosphoré. Ce type de cassure, inédit, permet d'accéder à des catalyseurs d'oligomérisation d'éthylène pour la production de chaînes courtes; 2) des diiminophosphoranes obtenus par fonctionnalisation distale d'un résorcinarène-cavitand. Un ligand de cette famille donne lieu à des sélectivités de forme en hydrogénation (Rh) de mélanges d'oléfines; 3) des phosphino-cavitands doubles permettant d’engendrer, par chélation, des métallo-capsules. L'une d'entre elles (Pt) conduit à des sélectivités remarquables en hydroformylation du styrène. / This thesis describes the synthesis of three types of phosphorus-containing resorcinarene cavitand: a) compounds with diphenylphosphino groups grafted to the wider rim of a generic cavity. These phosphines undergo facile, directed C–O bond breaking upon reaction with transition metal ions in the presence of exogenous or endogenous nucleophiles. A nickel complex of this type was shown suitable for the low pressure production of short α-olefins starting from ethylene; b) cavitands distally-substituted by two iminophosphoranyl groups (–Ph2P=NAr). One of them (Ar = p-anisyl), when combined with Rh(I), resulted in a shape-selective olefin hydrogenation catalyst; 3) double phosphino-cavitands, which upon chelation gave metallo-capsular complexes in which the metal centre is either fully or partially embedded in the resulting cavity. A platinum complex of this type resulted in the selective hydroformylation of styrene into the expected branched aldehyde.
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Synthesis, Characterization, and Self-Assembly of Gold Nanorods and NanoprismsTran, Kristina L. 29 June 2010 (has links)
The unique properties of gold nanoparticles make them excellent candidates for applications in electronics, sensing, imaging, and photothermal therapy. Though abundant literature exists for isotropic gold nanoparticles, work on nanoparticles of different shapes has been gaining interest recently. Anisotropic gold nanoparticles, such as nanorods and nanoprisms, have tunable optical properties in the visible and near-infrared regions. Through synthesis and surface modification, the production of various shapes of these gold nanoparticles can be controlled to meet different applications.
Two different types of gold nanorods were used in this thesis. The first type was stabilized with cetyltrimethylammonium bromide (CTAB) and had aspect ratios of 3-4 (defined as the nanorod length divided by the diameter). The second type was synthesized using CTAB and benzyldimethylhexadecylammonium chloride (BDAC) in a binary surfactant system which produced aspect ratios greater than 4. The nanorods were characterized with UV-Vis spectroscopy and transmission electron microscopy (TEM).
Two types of bowl-shaped macrocyclic compounds called resorcinarenes were used to direct self-assembly of the nanorods. The first type of resorcinarene (R2S) consisted of thiol(SH)-terminated alkyl chains on both rims. The second type (R1S) contained thiol-terminated alkyl chains on only one rim. The monolayer formation of these resorcinarenes on planar gold surfaces was studied and characterized by FTIR spectroscopy. Resorcinarene-mediated assembly of gold nanorods was monitored with UV-Vis spectroscopy, dynamic light scattering (DLS), and TEM. In addition to gold nanorods, gold nanoprisms were synthesized through a kinetically-controlled reduction route in the presence of CTAB. The linking of nanoprisms using resorcinarenes was also explored.
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