title: Synthesis and structures of cis- and trans-bis(alkyneselenolato)platinum(II) complexes.
abstract: The reaction of 2 equiv of LiSeCC-n-C(5)H(11) (1) with cis-PtCl(2)(Ph(3)P)(2) (2) gives a mixture of the cis and trans isomers of Pt(Ph(3)P)(2)(SeCC-n-C(5)H(11))(2) (3), which slowly isomerizes in CH(2)Cl(2) to the preferred trans form trans-3. The closely related cis-[Pt(dppf)(2)(SeCC-n-C(5)H(11))(2)] (4) (dppf = bis(diphenylphosphino)ferrocene) was prepared by a similar metathetical reaction using the platinum chloride complex of the chelating dppf to impose the cis geometry. The structures of the cis and trans complexes have been investigated in solution by heteronuclear NMR ((31)P, (77)Se, and (195)Pt) and, in the cases of trans-3 and 4, characterized in the solid state by single-crystal X-ray diffraction. Changing the coordination geometry from cis to trans induces significant changes in the structural and spectroscopic parameters, which do not comply with the previously anticipated donor-acceptor properties of selenolate ligands.
authors.affiliation: Fakultät für Chemie, Ruhr-Universität Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Schäfer
authors.forename: Carmen
authors.initials: C
authors.lastname: Moser
authors.forename: Jürgen J
authors.initials: JJ
authors.lastname: Tirrée
authors.forename: Martin
authors.initials: M
authors.lastname: Nieger
authors.forename: Rudolf
authors.initials: R
authors.lastname: Pietschnig