SYNTHESIS AND PROPERTIES OF COBALTACARBORANES WITH SUBSTITUTED MONOATOMIC BRIDGES BETWEEN LIGANDS OF THE 6,6'-MU-RNE(1,7-C2B9H10)(2)-2-CO TYPE

Syntheses, properties and constitutions of eleven asymmetric cobaltaca rboranes with various substituents on monoatomic bridges between both ligands of the type 6,6'-mu-RnE(1,7-C2ByH10)(2)-2-Co (E = O, R = methy l: E = S, R = ethyl, propyl, isopropyl, allyl, butyl, hexyl and CH3OCO CH2; E = N, R = H (H), methyl, (Hi, and dimethyl) are described. Const itution assignation of all compounds are based on H-1 and B-11 NMR spe ctroscopy experiments complemented by B-11-B-11 COSY NMR and mass spec trometry; UV-VIS, melting points and TLC parameters are also presented . Only the racemic forms were obtained, although in principle, the mes o-forms might result as well.