Dimetal units as building blocks of supramolecular arrays and mixed halide/phosphine complexas of the dirhenium core /
This dissertation consists of two independent topics: a) the synthesis of supramolecular assemblies using dimetal building blocks, and b) the study of the reactions of [Re₂Cl₈]²⁻ and [Re₂I₈]²⁻ with phosphines under different conditions. The use of metal-metal bonded Mo₂⁴⁺ and Rh₂⁴⁺complexes of the...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
2002.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=765069381&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | This dissertation consists of two independent topics: a) the synthesis of supramolecular assemblies using dimetal building blocks, and b) the study of the reactions of [Re₂Cl₈]²⁻ and [Re₂I₈]²⁻ with phosphines under different conditions. The use of metal-metal bonded Mo₂⁴⁺ and Rh₂⁴⁺complexes of the paddlewheel framework to direct the formation of supramolecular arrays has been recently developed as an effective route towards the construction of novel architectures. In this dissertation the efforts to extend this approach to other dimetal units (Ru₂⁵⁺, Re₂⁴⁺, and Cu₂²⁺) is described. In an effort to synthesize suitable precursor complexes of Ru₂⁵⁺ building blocks, the reactions of Ru₂([]-O₂CMe)₄Cl with formamidines under different experimental conditions were studied, from which a variety of mixed DArF⁻/MeCO₂⁻ complexes of the diruthenium core were obtained. One of these complexes, cis-([]-DAni[p]F)₂Ru₂Cl([]-O₂CMe)₂ (DAni[p]F⁻ = di(p-anisyl)formamidinate), was used in reactions with dicarboxylic acids which resulted in the formation of the first paramagnetic molecular squares based on dimetal units. Other types of supramolecular assemblies based on Re₂⁴⁺ and Cu₂²⁺ units have also been synthesized, by using suitable precursor complexes of dimetal building blocks. When cis-([]-dppm)₂Re₂⁴⁺ units were employed in reaction with terephthalate dianions a molecular triangle was obtained, whereas the use of ([]-dppm)₂Cu₂²⁺ units in reactions with dicarboxylates resulted in the formation of "dimers-of-dimers". For the reactions of [Re₂Cl₈]²⁻ with monodentate phosphines, it has been recently found that the nature of the solvent has a great influence on the reaction pathway. In this dissertation, the reactivity of [Re₂Cl₈]²⁻ with secondary phosphines PR₂H (R = Cy, Ph) has been studied and it has been shown that in solvents which cannot be the actual reducing agents, e.g., toluene, or benzene, a disproportionation mechanism is followed. The reactivity of [Re₂I₈]²⁻ with monodentate phosphines in EtOH and benzene has also been studied. For the reactions in EtOH, which result in two-electron reduced products, it has been found that the reactivity of [Re₂I₈]²⁻ contrasts strikingly with that observed for [Re₂Cl₈]²⁻, while the reactions in benzene appear to be similar to those of [Re₂Cl₈]²⁻ resulting in the same types of disproportionation products. |
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| Item Description: | Vita. "Major Subject: Chemistry". |
| Physical Description: | xv, 185 leaves : illustrations ; 28 cm. + 1 CD ROM. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 173-182). |