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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Studies on the reaction mechanism of chorismate synthase

Balasubramanian, Shankar January 1991 (has links)
No description available.
2

Studies of some aliphatic constituents of shellac

Prentice, Hugh Graham January 1962 (has links)
Hydrolysis of lac resin yields a mixture of acids among which only two - aleuritic (up to 40%) and shellolio (up to 5%) - have been adequately characterised and examined by several investigators. The work embodied in this thesis represents some studies of the aliphatic acids in lac hydrolysate. The presence of a range of non-hydroxy acids (1.1%) 6-hydroxytetra- decanoic acid (not less than 8%), l6~hydroxyhexadecanoic acid and snother monohydroxyhexadecanoic acid has been demonstrated. The 6-hydroxytetradecanoic acid has been shown to be identical with butolic acid recently isolated by chemists of the Indian Lac Research Institute but considered by them to be a C1B hydroxy acid. The other acids have not previously been reported as constituents of lac resin. Reversed-phase chromatography was found to be unsuitable for the examination of lac acids, probably due to their highly hydroxylated nature. Dehydroxylation experiments on lac acids by lodlnatlon- deiodination and by bromination-debrominatlon revealed the presence of hydroxylated tetradecanoic and hexadecanoic acids; brominatlon- debrominatlon reactions also showed the presence of small amounts of vicinal dihydroxy acids of these two series. Partition of lac acids between petroleum ether and 80% aqueous methanol and subsequent examination of the petroleum other-soluble material (1.1%) revealed the presence of dodecanoic (trace). tetradec-9-onoic and tetradecanoic acids (25%), hexadec-9-enoic acid (13%), hexadecanoic acid (53%), octadec-9-enoic acid (7%) and octadecanoic acid (2%). Examination of lac acids by adsorption, gas-liquid and thin layer chromatography showed the presence of 6-hydroxy-tetradecanoic acid (8% or more of lac acids), 16-hydroxy-hexadeoanoic acid and another monohydroxyhexadeoanoic acid.
3

Microwave assisted synthesis of ETS-4, ETS-10, ZIF-8, NTHU-4 and Fluorinated Tin Oxide materials /

Yamasaki, Jose Antonio Losilla, January 2006 (has links)
Thesis (M.S.) -- University of Texas at Dallas, 2006. / Includes vita. Includes bibliographical references (leaves133 -137)
4

The comparative toxicity of developmental inhibitors and organophosphates on mosquitoes

Orr, Richard L. 05 February 1976 (has links)
Four developmental inhibitors (Altosid, Altozar, ZR-619 and ZR-777) and two organophosphates (Parathion and Abate) were tested on Aedes aegypti under laboratory conditions. When applied to fourth-instar larvae, the organophosphates were more toxic than the developmental inhibitors. Concentrations required for standard kills (LC50 and LC95) were lower for Altosid and ZR-619 than for Altozar and ZR-777. Field applications of Altosid SR-10 controlled Culiseta inornata for two weeks at 4 ounces per acre. With the exception of Dolichopodidae, most non-target aquatic organisms showed little response to Altosid SR-10. Although the developmental inhibitors Altosid and ZR-619 require higher concentrations for mosquito control, they inflict a minimum amount of damage to non-target aquatic organisms.
5

Synthesis of Bioactive Nitrogen Heterocycles and Functionalized Nanomaterials for Biological and Catalytic Applications

Krishnan, Anand 15 January 2015 (has links)
Submitted in fulfillment of the requirements of the Degree of Doctor of Technology: Chemistry,Durban University of Technology, 2014. / Aromatic heterocycles are highly important structural units found in a large number of biologically active natural compounds, pharmaceuticals and catalytic compounds. They have a crucial role in organic syntheses, which results in the generation of high value products. Among heterocycles, those containing nitrogen are the most indispensable structural motifs and are widely used against dreaded diseases such as Malaria, TB, HIV/AIDS and Cancer. The inclusion of highly electronegative atoms such as fluorine in these organic molecules render them very reactive towards proteins. Furthermore these molecules exhibit strong interactions with surfaces of quantum range particles of elemental gold. Various approaches for the synthesis of novel gold nanoparticles linked to potent bioactive molecules are documented and their application as drug delivery systems are of immense value to human health. Also many chemical and physical methods are available for the synthesis of gold, silver and palladium nanoparticles however these methods are usually laborious and produce toxic by-products. The green approach is to use plant extracts to synthesise various size and shape nanoparticles which could be used in biological and catalytic systems. A simple one-pot two component and three component reaction using formyl quinoline, 2-aminothiophenol, thiosemicarbazone and trifluoromethylbenzaldehyde as a reactant to synthesise quinoline, pyridine and pyran based bioactive small molecules; these products are a quinoline type bearing a benzothiazole moiety, quinoline thio semicarbazone ligand, fluorine substituted dihydro pyridine, fluorine substituted dihydropyran and fluorine substituted pyridine derivatives. In total, fifteen compounds were synthesized eleven of which were novel; all compounds were characterized by spectroscopic techniques. In vitro anti-bacterial activities of the synthesized compounds were investigated against a representative panel of pathogenic strains. Compounds 6, 7, 8, 11 and 13 exhibited excellent anti-bacterial activity compared with first line drugs. Potent p53–MDM2 interaction inhibitors 2-thio-1,2-dihydroquinoline-3-carbaldehyde thiosemicarbazone and fluorine substituted new pyridine scaffold were successfully identified by structure-based design. An efficient one-pot four component route to the synthesis of trifluorinated pyrrolophenanthroline and fluoroquinoline pyrrolophenanthrolines was designed. In this reaction 1-butyl-2,3-dimethylimidazolium tetrafluoroborate ionic liquid (DMTIL) was used as a reaction medium; no catalyst was required. The structure of the pyrrolophenanthrolines was deduced by IR and NMR analysis. These compounds were studied with Bovine Serum Albumin (BSA) through molecular docking. Hydrophopic, electrostatic and hydrogen bonding interaction played a crucial role in the binding to sub domain of BSA. Interaction studies of DMTIL with BSA by emission, absorption, synchronous fluorescence, circular dichroism (CD) and three dimensional emission (3D) spectroscopic techniques were under taken. The results from emission titration experiments revealed the existence of a strong interaction between BSA and DMTIL ionic liquid. It showed that compounds with lesser number of hydrogen bonds are found to be more active which is attributed to hydrophobic interaction and electrostatic interaction which also played a vital role in DMTIL binding to sub domain IB of BSA. A novel copper-loaded boron nitride nanosheet (Cu/BN) catalyst was prepared and fully characterized. It was used as an efficient and chemoselective catalysts for the synthesis of α-aminophosphonates by the Kabachnik-Fields reaction; twenty one α-aminophosphonates were synthesised. The enhanced catalytic activity and product yield was attributed to the increase of surface acidity. Overall, this methodology offered competitive advantages such as recyclability of the catalyst without further purification or without using additives or cofactors, low catalyst loading, broad substrate applicability and high yields. The application of this new nanocatalyst in organic synthesis will provide a novel pathway for the synthesis of pharmaceutically important compounds. Gold nanoparticle surfaces were modified with self-assembled monolayers of important thiol and disulfide bioactive molecules since considerable interest is due to their potential application as anti-cancer agents. Herein, a carbazole was conjugated to lipoic acid by using an amide coupling catalyst HBTU and DIEA reaction. The structure of the carbazole thio octanic acid (CTN) was identified by IR and NMR. CTN was attached to the gold nanoparticles surface and the capping behaviour was characterized by UV-vis spectroscopy, TEM, DLS and FTIR. The cytotoxicity of CTNAuNPs on A549 cell lines was determined using the MTT assay. The results suggest CTN and CTNAuNPs possess anti-proliferative properties in the cancerous A549 cells. Furthermore a dual thiol ligand was synthesized by using equimolar 4-aminothiophenol (4-ATP) and amino oxadiazole thiol (AXT). This dual ligand was attached to the gold nanoparticles surface (DTAu) and the capping behaviour was characterized by UV-vis spectroscopy, TEM, DLS and FTIR. The cytotoxicity of DTAu on A549 cell lines was determined using the MTT assay. The results suggest dual ligands (4-ATP, AXT) and DTAu possess anti-proliferative properties in the cancerous A549 cells. South African indigenous plants and agroforestry waste were also used in the synthesis of silver, gold and palladium nanoparticles (NPs). Green protocols such as the use of environmentally benign solvents and non-hazardous reagents were an added advantage to physical and chemical means. Furthermore these reactions were rapid and the size and shape of the NPs could be manipulated by choosing the correct medium. The formulation of natural medicinal compounds capped onto NPs was assessed for their anti-cancer activity, in A549 lung cancer line, and catalytic reduction of dyes and nitrobenzene derivatives were studied. These NPs displayed: Significant cytotoxicity to lung cancer cells with minimal effect on normal healthy cells. Outstanding catalytic reduction of pharmaceutical and textile waste effluents such as dyes and nitro aromatic compounds. In addition, palladium nanoparticles containing capped Moringa olifera compounds were used effectively in the Suzuki coupling reaction of iodobenzene and phenylboronic acid. The reaction was rapid and was conducted in an aqueous medium.
6

The coordination chemistry of sterically bulky guanidinate ligands with chromium and the lanthanide metals.

January 2014 (has links)
本項研究工作主要對五個結構類似的胍基配體, 即 [(2,6-Me₂C₆H₃N)C(NHPri)(NPri)]⁻ (L¹), [(2,6-Me₂C₆H₃N)C(NHCy)(NCy)]⁻ (L²), [(2,6-Me₂C₆H₃N)C{N(SiMe₃)Cy}(NCy)]⁻ (L³), [(2,6-Pri₂C₆H₃N)C{N(SiMe₃)₂}(NC₆H₃Pri₂-2,6)]⁻ (L⁴) 和 [(2,6-Pri₂C₆H₃N)C(NEt₂)(NC₆H₃Pri₂-2,6)]⁻ (L⁵) 與二價鉻以及二價鑭系金屬[Sm(II)、Eu(II) 及 Yb(II)] 的配位化學進行研究,同時,一系列由 L¹ 配體所衍生的三價鑭系金屬配合物亦成功被合成。 / 第一章概括介紹了由胍基配體所構築的金屬配合物的研究背景。 / 第二章敍述了含 L¹ 與 L⁴ 的二價鉻配合物的合成、結構及其化學反應。 通過胍基鉀化合物 [KL¹・0.5PhMe] (1) 與二氯化鉻反應可得到單核二價鉻雙胍基配合物 [Cr(L¹)₂] (3)。 通過胍基鋰化合物 [LiL⁴(Et₂O)] (2) 與二氯化鉻反應,成功製備了單胍基二價鉻配合物 [Cr(L⁴)(μ-Cl)₂Li(THF)(Et₂O)] (4)。 而把二價鉻配合物 4於甲苯溶液中重結晶可得到二聚體的二價鉻配合物 [{Cr(L⁴)(μ-Cl)}₂] (5)。 另外,我們對二價鉻配合物 3 及 4 的反應特性也進行了研究。 [Cr(L¹)₂] (3) 與單質碘、二苯基硫族化合物 PhEEPh (E = S, Se, Te) 以及叠氮金剛烷反應可得相對應的三價鉻混合配體化合物,分別爲 [Cr(L¹)₂I] (6)、[Cr(L¹)₂(EPh)] [E = S (7), Se (8), Te (9)],及四價鉻配合物 [Cr(L¹)₂{N(1-Ad)}] (10)。 透過單胍基二價鉻配合物 [Cr(L⁴)(μ-Cl)₂Li(THF)(Et₂O)] (4) 與 NaOMe反應可得甲氧基-胍基配合物 [{Cr(L⁴)(μ-OMe)}₂] (11)。 / 第三章主要報導含 L¹, L², L³ 和 L⁵ 配基的二價鑭系配合物的合成、結構和化學反應特性。 透過 [LnI₂(THF)₂] (Ln = Sm, Eu, Yb) 與胍基鉀鹽反應,我們成功合成一系列二價鑭系絡合物,包括 [{Eu(L¹)(μ-L¹)}₂] (15), [{Ln(L²)(μ-L²)}₂・nC₆H₁₄] [Ln = Eu, n = 2 (16); Ln = Yb, n = 0 (17),[Yb(L²)₂(THF)₂] (18), [Ln(L³)₂(THF)₂・0.25C₆H₁₄] [Ln = Eu (19), Yb (20)], [{Sm(L³)(μ-I)(THF)}₂] (21) 和 [Sm(L⁵)₂] (22)。 本章亦同時探討二價鑭系配合物15, 18, 20 和 22 作爲還原劑的化學反應特性。 配合物 15 與單質碘反應可得三價銪配合物 [{Eu(L¹)₂(μ-I)}₂] (23)。 配合物 18 與二苯基硫族化合物 PhEEPh (E = S, Se) 反應,可得相對應的三價鐿配合物 [{Yb(L²)₂(μ-EPh)}₂] [E = S (24), Se (25)]。 18 與氯化亞銅反應得到三價鐿配合物 [{Yb(L²)₂(μ-Cl)}₂] (26)。 除此之外,配合物 18 與偶氮苯反應得到雙核配合物 [{Yb(L²)₂}₂(μ-η²:η²-PhNNPh)] (27), 而 20 與偶氮苯的反應可得單核配合物 [Yb(L³)₂(η²-PhNNPh)・PhMe] (28)。 配合物 22 與二硫化碳的反應得出不對稱偶合配合物 [(L⁵)₂Sm(μ-η³:η²-S₂CSCS)Sm(L⁵)₂] (29)。 / 第四章敍述由胍基配體 L¹ 所衍生的一系列三價鑭系金屬配合物 [Ln(L¹)₃] [Ln = Ce (30), Pr (31), Gd (32), Tb (33), Ho (34), Er (35), Tm (36)] 的合成及其結構。 通過相對應的鑭系金屬三氯化物與 1 反應可得配合物 30-36。 另外, CeCl₃及 LuCl₃與 1 反應亦可合成 [{Ln(L¹)₂(μ-Cl)}₂] [Ln = Ce (37), Lu (38)]。 / 第五章總結了本項研究工作,並對本工作的未來發展作出建議。 / This research work is focused on the coordination chemistry of five closely related guanidinate ligands, namely [(2,6-Me₂C₆H₃N)C(NHPri)(NPri)]⁻ (L¹), [(2,6-Me₂C₆H₃N)C(NHCy)(NCy)]⁻ (L²), [(2,6Me₂C₆H₃N)C{N(SiMe₃)Cy}(NCy)]⁻ (L³), [(2,6Pri₂C₆H₃N)C{N(SiMe₃)₂}(NC₆H₃Pri₂-2,6)]⁻ (L⁴) and [(2,6-Pri₂C₆H₃N)C(NEt₂)(NC₆H₃Pri₂-2,6)]⁻ (L⁵), with divalent chromium and lanthanide metal ions. A series of trivalent lanthanide derivatives of the L¹ ligand were also prepared and structurally characterized in this work. / Chapter 1 gives a brief introduction to the chemistry of metal guanidinate complexes. / Chapter 2 reports on the synthesis, structure and reactivity of chromium(II) complexes derived from the bulky L¹ and L⁴ ligands. Treatment of CrCl₂ with [KL¹・0.5PhMe] (1) afforded the mononuclear Cr(II) bis(guanidinate) complex [Cr(L¹)₂] (3). Reaction of CrCl₂ with [LiL⁴(Et₂O)] (2) resulted in the isolation of ate-complex [Cr(L⁴)(μ-Cl)₂Li(THF)(Et₂O)] (4). Recrystallization of 4 from toluene gave neutral, dimeric [{Cr(L⁴)(μ-Cl)}₂] (5). The reaction chemistry of the Cr(II) complex 3 and 4 was studied. Treatment of 3 with I₂, PhEEPh (E = S, Se, Te), 1-AdN₃ (1-Ad = 1-adamantyl) gave the corresponding mixed-ligand Cr(III) complexes, namely [Cr(L¹)₂I] (6) and [Cr(L¹)₂(EPh)] [E = S (7), Se (8), Te (9)] and Cr(IV) complex [Cr(L¹)₂{N(1-Ad)}] (10). Besides, the reaction of 4 with NaOMe resulted in the isolation of the Cr(II) methoxide-guanidinate complex [{Cr(L⁴)(μ-OMe)}₂] (11). / Chapter 3 deals with the synthesis, structure and reactivity of lanthanide(II) complexes supported by the L¹, L², L³ and L⁵ ligands. Lanthanide(II) guanidinate complexes were prepared by the reactions of an appropriate lanthanide diiodide with the corresponding potassium guanidinate complexes [KL¹・0.5PhMe] (1), [KL²(THF)₀.₅]n (12), KL³ (13) and [KL⁵(THF)₂] (14). Reaction of EuI₂(THF)₂ with 1 gave the homoleptic complex [{Eu(L¹)(μ-L¹)}₂] (15). Metathesis reactions of LnI₂(THF)₂ (Ln = Yb, Eu) with 12 and 13 led to the isolation of [{Ln(L²)(μ-L²)}₂・nC₆H₁₄] [Ln = Eu, n = 2 (16); Ln = Yb, n = 0 (17)], [Yb(L²)₂(THF)₂] (18) and [Ln(L³)₂(THF)₂・0.25C₆H₁₄] [Ln = Eu (19), Yb (20)]. Direct reaction of SmI₂(THF)₂ with 13 yielded the iodide bridged Sm(II) complex [{Sm(L³)(μ-I)(THF)}₂] (21), whilst reaction of SmI₂(THF)₂ with 14 gave homoleptic [Sm(L⁵)₂] (22). The reaction chemistry of 15, 18, 20 and 22 as reducing agents was examined. Oxidation of 15 with I₂ afforded the Eu(III) complex [{Eu(L¹)₂(μ-I)}₂] (23). Reactions of 18 with PhEEPh (E = S, Se) gave the corresponding Yb(III) chalcogenide complexes [{Yb(L²)₂(μ-EPh)}₂] [E = S (24), Se (25)], whilst treatment of 18 with CuCl led to the isolation of [{Yb(L²)₂(μ-Cl)}₂] (26). Besides, addition of complex 18 to PhNNPh yielded binuclear [{Yb(L²)₂}₂(μ-η²:η²-PhNNPh)] (27), whereas treatment of 20 with PhNNPh resulted in the isolation of mononuclear [Yb(L³)₂(η²-PhNNPh)・PhMe] (28). Addition of CS₂ to 22 gave the unsymmetrical coupling product [(L⁵)₂Sm(μ-η³:η²S₂CSCS)Sm(L⁵)₂] (29). / Chapter 4 describes the preparation and structural characterization of lanthanide(III) complexes derived from L¹. A series of homoleptic lanthanide(III) tris(guanidinate) complexes [Ln(L¹)₃] [Ln = Ce (30), Pr (31), Gd (32), Tb (33), Ho (34), Er (35), Tm (36)] were prepared by the reactions of an appropriate LnCl₃ with three molar equivalents of 1. Treatment of CeCl₃ and LuCl₃ with two equivalents of 1 gave the corresponding chloride bridged guanidinate complexes [{Ln(L¹)₂(μ-Cl)}₂] [Ln = Ce (37), Lu (38)]. / Chapter 5 summarizes the findings of this study. A short description on the future prospect of this work will also be given. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Au, Chi Wai. / Thesis (Ph.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references. / Abstracts also in Chinese.
7

Black Bean Milling and Flour Functionality

Fernando, Hettige Supun Sandaru January 2020 (has links)
Dry bean utilization by the food industry can be increased by developing value-added processing applications. The goals of this research were to evaluate (1) the effect of milling method on the physical, chemical and functional properties of whole black bean flour and its fractions and (2) the effect of removing soluble phenolic compounds on the functional and rheological properties of black bean protein isolates. Black bean was milled with five laboratory mills [cyclone mill, hammer mill, stone mill (fine, medium, coarse), disc mill (fine, coarse), and centrifugal mill (10,000 or 12,000 rpm and 250, 500, 1000 μm aperture screen)] and the resulting flours were evaluated for their physical, chemical and flow properties of bulk samples and particle size fractions. Whole black bean flour and cotyledon flour were subjected to phenolic extraction and protein isolation, resulting in protein isolates with and without soluble phenolics. Solubility, wettability, dispersibility, water binding capacity, foam capacity and stability, emulsification capacity, and gelation properties of protein isolates were evaluated. Variation in milling method produced flours with significantly different flour characteristics. Geometric mean size of whole bean flour was negatively correlated with starch damage (r = -0.92), L* (r = -0.94), angle of repose (r = -0.94), and angle of slide (r = -0.80 to -0.90) and positively correlated with moisture (r = 0.72), and loose bulk density (r = 0.72). Milling method and particle size interaction was significant on characteristics of black bean flour fractions. Particle circularity of flour fractions had a negative correlation of r = -0.93, r = -0.81, r ≈ -0.95, and r = -0.94 with L*, angle of repose, angle of slide and compact density, respectively. Particle circularity had a positive correlation of r = 0.93 and r = 0.89 with average minimum particle size and loose bulk density, respectively. The removal of soluble phenolic compounds improved the brightness, solubility, wettability, dispersibility, foaming capacity, foaming stability, emulsion capacity, emulsion stability and gelling properties of protein isolates. These findings will help food manufacturers to process black bean ingredients using different mill settings to achieve different functionalities depending on the consumer requirements.
8

Establishing the Structure Function Relationship of Polypyridyl Ruthenium and Berenil-type Compounds in the Formation of Complexes with B-DNA and/or G-quadruplex DNA

Mikek, Clinton Gregory 08 December 2017 (has links)
Cancer results from the accumulation of genetic mutations in a normal cell that ultimately result in the expression (or overexpression) of oncogenes. The design of drugs having high affinity for specific DNA sequences or structural motifs is vital to gaining a better understanding of gene expression and to the development of new cancer treatments that are based on turning off oncogene expression. This dissertation presents studies of the binding of two ligand families, Berenil (DMZ), and ruthenium polypyridyl complexes (RPCs), to B-DNA and G-quadruplex (G4) DNA. The structureunction relationships for the interaction of these ligand families with DNA were probed by functional group substitution, truncation, or modification of the DMZ amidine groups, and by changing one of the RPC ruthenium ligands from phenanthroline to dipyridophenazine (dppz) or tetraazatetrapyrido-pentacene (tatpp), and lastly by adding a second Ru(Phen)2 core to the tatpp bridging ligand. Removal of one or both amidine groups from DMZ drastically reduces its binding to both B-DNA and G4-DNA. DMZ analogs in which one amidine was replaced by an alkyne group were synthesized with the expectation that the additional π-bonding character of the alkyne group would increase G4 affinity. All of the DMZ alkyne compounds were found to bind preferentially to G4-DNA (over B-DNA) and a few of these compounds demonstrated significant anticancer activity. RPCs with progressively longer ruthenium bound ligands were found to bind with differing affinities to B-DNA and G4-DNA. Monoruthenium RPCs exhibited a preference for binding to B-DNA, while binding the diruthenium RPC to G4-DNA was more complicated exhibiting both tighter and a weaker binding modes in comparison to the B-DNA complex. The diruthenium complex was found to bind more tightly to G4-DNA by approximately 3 kcal mol-1. The binding of small molecules to DNA resulting in the disruption of oncogene transcription represents a powerful approach to the treatment of cancer.
9

Identification, Characterization, and Ontogenic Study of Three Novel Zebrafish Cytosolic Sulfotransferases (SULTs)

Mohammed, Yasir Ihsan 01 June 2011 (has links)
No description available.
10

Supramolecular transition metal architectures

Cordes, David B., n/a January 2005 (has links)
This thesis describes the investigation of the coordination and supramolecular chemistry of three different types of pyridine-containing ligand with a selection of Ag(I), Cu(I), Cu(II) and Cd(II) salts. The ligand types are flexible and four-armed, rigid and four-armed and bent with two rigid arms. All the ligands also display the ability to form additional supramolecular interactions. Chapter one introduces supramolecular chemistry and crystal engineering and covers background on several areas of current interest in these fields. Network structures, both coordination polymers and hydrogen-bonded systems, are discussed and topological analysis as a method of describing and comparing network structures is introduced. An outline of the ligand design, choice of transition metals and anions is given. Chapter two provides a review of flexible four-armed pyridine-containing ligands and their use in coordination chemistry. The synthesis and characterisation of three flexible four-armed ligands 1,2,4,5-tetrakis(2-pyridylmethyl-sulfanylmethyl)benzene (2tet), 1,2,4,5-tetrakis(3-pyridylmethyl-sulfanylmethyl)benzene (3tet) and 1,2,4,5-tetrakis(4-pyridylmethyl-sulfanylmethyl)benzene (4tet) are given. The synthesis and characterisation of the Ag(I), Cu(II) and Cd(II) complexes formed with these three ligands are also given. The complex of [Cd(2tet)(NO₃)₄] was structurally characterised by X-ray diffraction and was found to be a discrete species. The complexes {[Ag₂(3tet)](ClO₄)₂}n̲, {[Ag₂(3tet)](PF₆)₂}n̲, {[Ag₂(3tet)](CF₃CO₂)₂}n̲, {[Ag₂(4tet)]-(ClO₄)₂�2MeCN�2CHCl₃}n̲, {[Ag₂(4tet)](PF₆)₂�6MeCN}n̲ and {[Ag₂(4tet)](ClO₄)₂-�3H₂O}n̲ were likewise structurally characterised by X-ray diffraction. All these complexes were three-dimensional coordination polymers. A comparison of the seven structures is given at the end of the chapter. Chapter three reviews rigid four-armed pyridine-containing ligands and their use in coordination chemistry. The preparation of the rigid four-armed ligand 2,3,4,5-tetrakis(4-pyridyl)thiophene (pyth) is given. The synthesis and characterisation of the Ag(I), Cu(I) and Cd(II) complexes formed with this ligand are also given. The complexes [Ag(pyth)](BF₄)�3MeCN�CH₂Cl₂}n̲, [Ag(pyth)](PF₆)�MeCN�CH₂Cl₂}n̲, [Ag(pyth)]-(CF₃SO₃)�2MeCN�CH₂Cl₂}n̲, [Cu(pyth)](PF₆)�MeCN�CH₂Cl₂}n̲ and [(Cu₂I₂)(pyth)]-(BF₄)�1/2CH₂Cl₂�H₂O}n̲ were structurally characterised by X-ray diffraction. The complex with CuI was a two-dimensional coordination polymer, and the other four complexes were three-dimensional coordination polymers. A comparison of the five structures is given at the end of the chapter. Chapter four begins with a review of rigid angular bridging ligands and their use in coordination and supramolecular chemistry. The preparation of the ligand bis(4-pyridyl)amine (bpa) is given. The structural arrangement of bpa in the solid state was determined by X-ray diffraction. Complexes of Ag(I), Cu(I), Cu(II) and Cd(II) formed with this ligand were synthesised and characterised. The complexes {[Ag(bpa)(MeCN)](CF₃SO₃)}n̲, {[Ag(bpa)](PF₆)�MeCN}n̲, {[Ag(bpa)](ClO₄)-�2MeCN}n̲, {[Ag(bpa)](ClO₄)}n̲, {[Ag(bpa)](NO₃)}n̲, [(Cu₂I₂)(bpa)₂]n̲, {[Cu(bpa)₂Cl₂]-�3DMF�3/2H₂O}n̲, {[Cd(bpa)₂(NO₃)(H₂O)](NO₃)}n̲, {[Cd(bpa)₂(SO₄)(H₂O)]�3H₂O}n̲, [Cd(bpaH)₂(SO₄)₂(H₂O)₂]�2MeCN and {[Cd(bpa)(SCN)₂]�1/5iPrOH}n̲ were structurally characterised by X-ray diffraction. All complexes with Ag(I) were one-dimensional coordination polymers, with two of them helical, the other three zigzag. Both complexes with Cu(I) and (II) were two-dimensional coordination polymers. One complex with CdSO₄ was discrete, with the bpa ligands mono-protonated, but all other three other Cd(II) complexes were three-dimensional coordination polymers. Seven of these complexes showed hydrogen-bonding interactions linking them together to form supramolecular structures of higher dimensionalities. A comparison of the twelve structures is given at the end of the chapter. Chapter five is a brief summary of the outcomes of this thesis.

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