Syntheses, structures and electrochemistry of some 1-(η2-allylamino)-1-ferrocenylcarbene complexes of chromium(0), molybdenum(0) and tungsten(0) -: Part 13:: The chemistry of metallacyclic alkenylcarbene complexes

The metallacyclic Complexes (OC)(4)M=C(eta(2)-NHCH2CH=CHX)Fc (4; X = H) and (5; X = CH2OH) [M = Cr: a; Mo: b; W: c; Fc = ferrocenyl = CpFe(C5H4)] were obtained in good yields upon photo-decarbonylation of the bimetallic allylaminocarbene complexes (OC)(5)M=C(NHCH2CH=CHX)Fc (2; X = H)/(3; X = CH2OH). At room temperature complexes 2/3 exist as mixtures of E- and predominantly Z-isomers with regard to the C-N bond. The molecular structures of 4b and 4c were determined by X-ray diffraction analyses. The intermetallic communicative effects and the interplay of Fc and eta(2)-alkene moieties of 4a and 4b were assessed by cyclovoltammetry. All complexes were also characterized in solution by one- and two-dimensional NMR spectroscopy (H-1, C-13, H-1 NOE, H-1/H-1 COSY, C-13/H-1 HETCOR). (c) 2005 Elsevier B.V. All rights reserved.