SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF RARE-EARTH-METAL DISULFONAMIDE COMPLEXES

The reaction of rare earth silylamides Ln[N(SiHMe2)(2)](3)(thf)(n) [n = 1 for Sc (1a); n = 2 for Y (1b), La (1c), Nd (1d)] with s(2,4,6-trii sopropylbenzenesulfonamido)cyclohexane (H2L, rac-2) in toluene at ambi ent temperature proceeds via an extended silylamide route, affording h ighly soluble complexes Sc(L)[N(SiHMe2)(2)] (3) and Ln(L)[N(SiHMe2)(2) ] (thf) (4a-c) in excellent yields. An X-ray crystallographic study pe rformed on the solvent-free, dinuclear yttrium derivative 5 revealed a n unusual mu(2),eta(4):eta(1)-coordination of the disulfonamide Ligand , involving bridging S=O groups. In solution, equilibria between dimer ic and monomeric forms, dependent on the presence of a donor molecule, were observed by NMR techniques.