SYNTHESIS OF ENYLPHOSPHINOMETHYL)PYRIDINE-MONOLIGAND-RHODIUM(I) COMPLEXES [RH(PNP)L]X WITH L = PYRIDINE, CH3CN, DMSO AND X = CF3SO3, BF4 FROM THE CORRESPONDING ETHYLENE COMPLEX AND COMPARISON OF THE STRUCTURESTO THE PIPERIDINE COMPLEX (L = PIPERIDINE, X = BF4)

Investigation of the coordination conditions at the ,6-bis(diphenylpho sphinomethyl)pyridine-rhodium(I) fragment [Rh(PNP)](+) by X-ray crysta llography showed a square planar geometry of the neutral chloro and th e cationic piperidine complexes, [Rh(PNP)Cl] (1) and [Rh(PNP)(pip)]BF4 (2). New cationic rhodium(I) complexes [Rh(PNP)L]X (L = pyridine, X = SO3CF3 3; L = CH3CN, X = SO3CF3 4a, X = BF4 4b; L = DMSO, X = SO3CF3 5) have been synthesized from the ethylene complexes [Rh(PNP)(C2H4)]X by substitution of the ethylene by the ligand L (L = py, CH3CN, or DMS O). The complexes 3-5 were characterized by IR spectroscopy, H-1-, C-1 3-, and P-31-NMR spectroscopy and X-ray crystallography. The influence of the ligands on the structure of the complexes was investigated. Th e cis influence was determined by measurement of the coupling constant J(P-Rh) and the average length of the Rh-P bonds and the trails influ ence by the length of the Rh-N(1) bond. (C) 1998 Elsevier Science Ltd. All rights reserved.