COMMON AND LESS-COMMON COORDINATION MODES OF THE TYPICAL CHELATING AND HETEROAROMATIC LIGANDS

Data on the different modes of bonding the metals to the most widely s pread chelating [beta-diketones, o-oxyazomethines, o-oxy(mercapto) der ivatives of azoles and azines] and heteroaromatic ligands are generali zed and systematized. It is shown that, besides the common beta-diketo nates, aldiminates, phenolates and mercaptophenolates structures, thes e complex compounds exhibit less-common modes of coordination. Five- a nd six-membered heterocycles form sigma- as well as pi-complexes. (C) 1998 Elsevier Science S.A.