TETRACYANOQUINODIMETHANIDE DERIVATIVES OF NORBORNADIENE RHODIUM(I) FRAGMENTS

The rhodium derivatives [Rh(nbd)(N-N)]X, (nbd = norbornadiene, N-N = b py, phen, X = ClO4, BPh(4))react with anionic TCNQ(-) (7,7,8,8-tetracy anoquinodimethanido) , with total or partial substitution of the count erion but no change in the metal coordination sphere. On the contrary, rhodium derivatives with monodentate nitrogen-donor ligands, such as isoquinoline and substituted pyridines, [Rh(nbd)(N)(2)](+) (N = 2,5-Me (2)C(5)H(3)N), suffer substitution of these ligands and formation of [ Rh(nbd)(TCNQ)], for which a dimeric structure with the TCNQ acting as bridges is proposed. By using the mixture TCNQ(radical anion)/TCNQ deg rees the complexes with bidentate amines give rise to [Rh(nbd)(N-N)](T CNQ)(2) whose conductivity values are indicative of a higher degree of electronic delocalization in the organic donor units.