METAL-SELENIUM INTERACTIONS. SYNTHESIS AND CRYSTAL STRUCTURE OF [DIIODO{1,1′-METHYLENE-BIS (DIPHENYL PHOSPHINE SELENIDE)}] ZINC(II)

Abstract

Reaction of 1,1′-methylenebis(diphenylphosphine selenide) {Ph2P(Se)—CH2—P(Se)Ph2, dpmSe2} with zinc(II) diiodide in dry diethylether-benzene mixture formed Znl2(dpmSe2) (1), which has been characterised with the help of analytical data, IR spectroscopy and single crystal X-ray crystallography. Zinc(II) is bonded to two iodine atoms {Zn—I, 2.5732(9), 2.5584(7) Å} and two selenium atoms {Zn—Se, 2.5135(8), 2.4906(10) Å}. The angles about Zn vary from 103.56(3) to 114.69(3) Å, with Se(1)—Zn—Se(2) and I(1) bond angles being 104.57(3) and 114.69(3) Å, respectively. Thus dpmSe2 chelates to Zn(II) forming a distorted tetrahedral geometry about the metal centre. In the six membered metallacyclic ring formed by Zn(1), Se(1), P(1), C(13), P(2) and Se(2) atoms, the angles at Se atoms, namely, Zn(1)—Se(1)—P(1) and Zn(1)—Se(2)—P(2) {96.86(4) and 100.67(5)°, respectively} are the lowest. This reveals higher angular flexibility at Se atom vis-à-vis angles at P or C atoms. Complex 1 is the first example of a complex of zinc(II) with a tertiary phosphine selenide ligand, whose structure has been solved.