SYNTHESIS AND SPECTROSCOPIC STUDIES OF TRANS AND CIS RHODIUM(III) COMPLEXES OF O-C6H4(PME(2))(2) AND O-C6H4(ASME(2))(2) - CRYSTAL-STRUCTURES OF TRANS-[RH(O-C6H4(PME(2))(2))CL-2(2)]CL AND TRANS-[RH(O-C6H4(ASME(2))(2))I-2(2)]BF4

The rhodium(III) complexes trans-[Rh(L-L)(2)X(2)](+) [L-L = o-C6H4(PMe (2))(2) or o-C6H4(AsMe(2))2, X = Cl, Br or I] have been prepared from RhX(3) . nH(2)O and L-L, and converted to the cis-[Rh(L-L)(2)X(2)](+) by sequential treatment with Li2CO3 and HX. Both series of compounds h ave been characterized by analysis, UV-vis and multinuclear (H-1, P-31 {H-1} and Rh-103) NMR spectroscopy. The trends in the Rh-103 chemical shifts with L-L, X and stereochemistry are discussed. The crystal str uctures of trans-[Rh{o-C6H4(PMe(2))(2)}Cl-2(2)]Cl and trans-[Rh{o-C6H4 (AsMe(2))(2)}I-2(2)]BF4 have been determined. Copyright (C) 1997 Elsev ier Science Ltd.