Chelating and ligand-transfer studies of the complexes cis-[Mn(CO)(4)(SeR)(2)](-): crystal structures of heterotrinuclear [(CO)(4)Mn(mu SeMe)(2)Ni(mu-SeMe)(2)Mn(CO)(4)] with a distorted square planar Ni-II-selenolate core and [PPN](2)[Cl2Pd(mu-SePh)(2)PdCl2]

Trinuclear selenolate complexes [(CO)(4)Mn(mu-SeR)(2)Ni(mu-SeR)(2)Mn(CO)(4) ] (R = Me, Ph) containing a distorted square planar Ni(Se)(4) core have bee n synthesized by the reaction of Ni(NO3)(2). 6H(2)O/NiCl2 with the chelatin g metalloligand cis-[PPN][Mn(CO)(4)(SeR)(2)] in MeCN. Their structures were elucidated on the basis of IR, UV-Vis, CV, and NMR spectra. X-ray crystall ography confirmed the heterotrinuclear structure in the solid state with a Ni-II-Se distance of 2.331(1) Angstrom, and a Ni-II... Mn-I distance of 3.4 28(2) Angstrom (average). The dependence of geometry on electron population and the larger Ni-II... Mn-I distances are adopted to rationalize the cons truction of the complex [(CO)(4)Mn(mu-SeMe)(2)Ni(mu-SeMe)(2)Mn(CO)(4)] with a distorted square planar Ni-II(Se)(4) core. Further reaction of cis-[PPN] [Mn(CO)(4)(SePh)(2)] with PdCl2 afforded [PPN](2)[Cl2Pd(mu-SePh)(2)PdCl2]. Its structure has been determined. This investigation shows that cis-[Mn(CO )(4)(SeR)(2)](-) serves as a chelating metalloligand and selenolate ligand- transfer reagent. (C) 1999 Elsevier Science S.A. All rights reserved.