Lotz, SimonVan Jaarsveld, Nina AllettaLiles, David C.Crause, ChantelleGörls, HelmarTerblans, Yvette M.2017-01-192017-01-192012Lotz, S, Van Jaarsveld, NA, Liles, DC, Crause, C, Görls, H & Terblans, YM 2012, 'Fischer dinuclear and mononuclear bis-carbene complexes of thiophene and thiophene derivatives', Organometallics, vol. 31, no. 15, pp. 5371-5383.0276-7333 (print)1520-6041 (online)10.1021/om300414yhttp://hdl.handle.net/2263/58569The reaction of dilithiated thiophene and thiophene derivatives with group 6 transition metal carbonyl precursors and subsequent alkylation afforded linearly arranged Fischer 2,5-bis-carbene and the rare unsymmetrical 2,3-bis-carbene chelated complexes. The latter requires a second lithiation to occur at an adjacent, less reactive site on the thiophene ring. The control of reactivity sites was investigated and achieved by either blocking more reactive positions with substituents or activating less reactive positions by lithium−halogen exchange reactions. A series of Fischer bis-carbene chelates were synthesized by manipulating the above variables. Structural features of Fischer mono-carbene, mononuclear bis-carbene, and bis-carbene chelated complexes were studied by IR, NMR, and single-crystal X-ray diffractionenThis document is the Accepted Manuscript version of a Published Work that appeared in final form in Organometallics, © 2012 American Chemical Society after peer review and technical editing by the publisher.Fischer dinuclearMononuclear bis-carbene complexesThiopheneThiophene derivativesPostprint Article