SUBSTITUTED 2,2'-BIPYRIDINES AS LIGANDS. PREPARATION AND CHARACTERIZATION OF 4,4'-DISUBSTITUTED 2,2'-BIPYRIDINE DERIVATIVES OF THE HEXACARBONYLS OF CHROMIUM, MOLYBDENUM AND TUNGSTEN

Article abstract of DOI:10.1016/S0022-328X(00)98807-7

The preparation of cis- (M=Cr, Mo, W; biL is 4,4'-X2-2,2'-bipyridine; X=NMe2, NH2, OMe, CMe3, Me, H, Ph, CH=CHPh, Cl, CO2H, CO2Me, NO2) is reported.The ligands and complexes are characterized by spectroscopy (IR, electronic absorption and emission, NMR (1H, 13C, 15N, 95Mo)) and microanalysis.The variations observed in the spectroscopic properties of these complexes are strongly correlated with electronic substituent parameters of the group X.This is most apparent in the lowest energy (visible) absorption which changes by ca. 0.8 eV between the extremes of donor and off acceptor substituent used.