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Biscarbene complexes of Bithiophene

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dc.contributor.advisor Landman, Marilé en Ramontja, James en 2009-08-25T10:50:40Z 2009-08-25T10:50:40Z 2009-08 2005-11-30 en
dc.identifier.citation Ramontja, James (2009) Biscarbene complexes of Bithiophene, University of South Africa, Pretoria, <> en
dc.description.abstract Binuclear mixed biscarbene complexes of bithiophene were synthesized via the classical Fischer method of synthesis. The metal carbonyls, Mo(CO)6, Cr(CO)6, W(CO)6 and Mn(MeCp)(CO)3 were reacted with dilithiated bithiophene to afford complexes of the formula, [M(CO)5{C(OEt)C4H2S-C4H2SC(OEt})M'(CO)5] (in case of manganese, M(CO)5 is replaced with MMeCp(CO)2), where [M] and [M'] are the metal carbonyls in different combinations. Quenching was achieved with triethyl oxonium tetrafluoroborate. In all the reactions the products included monocarbene complexes, biscarbene complexes and the decomposition products. C-C coupling reactions produced unexpected biscarbene complexes of Cr, W, and Mo having extended bithiophene spacers. The complexes were of the formula, [M(CO)5{C(OEt)C4H2S-C4H2SC(R)-C(R)C4H2S-C4H2SC(OEt})M'(CO)5] (R = O, OH or OEt). These complexes were characterized with NMR, infrared spectroscopy and some with mass spectrometry. Furthermore, three biscarbene complexes of the metal combinations Mo(CO)6 and Cr(CO)6, W(CO)6 and Cr(CO)6, and Mn(MeCp)(CO)3 and Cr(CO)6 were all reacted with 3-hexyne. The result was the benzannulation or the Dötz products. en
dc.format.extent 1 online resource (83 leaves)
dc.language.iso en en
dc.subject Manganese en
dc.subject Chromium en
dc.subject Molybdenum en
dc.subject Tungsten en
dc.subject Biscarbene complexes en
dc.subject Bithiophene and Dötz products en
dc.subject.ddc 546.54
dc.subject.lcsh Manganese
dc.subject.lcsh Chromium
dc.subject.lcsh Molybdenum
dc.subject.lcsh Tungsten
dc.title Biscarbene complexes of Bithiophene en
dc.type Dissertation en
dc.description.department Chemistry en M. Sc. (Chemistry) en

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