Syntheses, structures and electrochemistry of some 1-(η 2-allylamino)-1-ferrocenylcarbene complexes of chromium(0), molybdenum(0) and tungsten(0) : Part 13: The chemistry of metallacyclic alkenylcarbene complexes

Abstract

The metallacyclic complexes (OC) 4M C(η 2-NHCH 2CH CHX)Fc ( 4; X = H) and ( 5; X = CH 2OH) [M = Cr: a; Mo: b; W: c; Fc = ferrocenyl = CpFe(C 5H 4)] were obtained in good yields upon photo-decarbonylation of the bimetallic allylaminocarbene complexes (OC) 5M C(NHCH 2CH CHX)Fc ( 2; X = H)/( 3; X = CH 2OH). 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 η 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 ( 1H, 13C, 1H NOE, 1H/ 1H COSY, 13C/ 1H HETCOR).