Metal–metal interaction in Fischer carbene complexes : a study of ferrocenyl and biferrocenyl tungsten alkylidene complexes

Show simple item record Van der Westhuizen, Belinda Speck, J. Matthaus Korb, Marcus Friedrich, Joachim Bezuidenhout, Daniela Ina Lang, Heinrich 2014-02-04T13:28:12Z 2013
dc.description.abstract A series of ferrocenyl (Fc = ferrocenyl; fc = ferrocen-1,1'-diyl) and biferrocenyl (Bfc = 1',1''-biferrocenyl; bfc = 1',1''-biferrocen-1,1'''-diyl) mono- and biscarbene tungsten(0) complexes of the type [(CO)5W=C(OMe)R] (1, R = Fc; 3, R = Bfc) and [(CO)5W=C(OMe)-R'-(OMe)C=W(CO)5] (2, R' = fc; 4, R' = bfc) were synthesized according to the classical synthetic methodology by reacting W(CO)6 with LiR (R = Fc, fc, bfc), followed by a subsequent alkylation using methyl trifluoromethanesulfonate. Electrochemical investigations were carried out on these complexes to get a closer insight into the electronic properties of 1 - 4. The ferrocenyl and biferrocenyl moieties in 1 – 4 show reversible one electron redox events. It was further found that the Fischer carbene unit is reducible in an electrochemical one electron transfer process. For the tungsten carbonyl moieties, irreversible oxidation processes were found. In addition, charge transfer studies were performed on 1 - 4 by the use of in situ UV-Vis-NIR and infrared spectroelectrochemical techniques. During the UV-Vis-NIR investigations typical low energy transitions for the mixed-valent biferrocenyl unit were found. A further observed high energy NIR absorption is attributed to a metal-metal charge transfer transition between the tungsten carbonyl fragment and the ferrocenyl/biferrocenyl group in the corresponding oxidized states, which can be described as class II systems according to Robin and Day. This assignment was verified by infrared spectroelectrochemical studies. The electrochemical investigations are supported by DFT calculations. The structural properties of 1 - 4 in the solid state were investigated by single-crystal Xray diffraction studies showing no substituent effects on bond lengths and angles. The biferrocenyl derivatives exhibit synconformation of the ferrocenyl and carbene building blocks. en_US
dc.description.librarian hb2014 en_US
dc.description.sponsorship D.I.B. and B.v.d.W. acknowledge the National Research Foundation, South Africa for financial support (Grant number 76226). We are grateful to the Fonds der Chemischen Industrie for financial support. J.M.S. and M.K. thank the FCI for Chemiefonds Fellowships. en_US
dc.description.uri en_US
dc.identifier.citation Van der Westhuizen, B, Speck, JM, Korb, M, Friedrich, J, Bezuidenhout, DI & Lang, H 2013,'Metal–metal interaction in Fischer carbene complexes : a study of ferrocenyl and biferrocenyl tungsten alkylidene complexes', Inorganic Chemistry, vol.52, no. 24, pp.14253-14263. en_US
dc.identifier.issn 0020-1669 (print)
dc.identifier.issn 1520-510X (online)
dc.identifier.other 10.1021/ic402202w
dc.language.iso en en_US
dc.publisher American Chemical Society en_US
dc.rights © 2013 American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Inorganic Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see : en_US
dc.subject Spectroelectrochemistry en_US
dc.subject Metal-metal interaction en_US
dc.subject Ferrocene en_US
dc.subject Biferrocene Fischer carbene complexes en_US
dc.title Metal–metal interaction in Fischer carbene complexes : a study of ferrocenyl and biferrocenyl tungsten alkylidene complexes en_US
dc.type Postprint Article en_US

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