Studies in the stereochemistry of zinc(II). VII. Zinc complexes with dialkyldithiophosphates

Abstract

A series of bis(O,O-dialkyldithiophosphato)zinc(11) complexes, ZnL₂ (LH = (R0)₂PS₂H; R = Et, Prⁱ, Bu, Buⁱ, Bus, cyclohexyl), has been isolated. Pyridine adducts ZnL₂(py)₂ (R = Et, Pr, Prⁱ, Buⁱ) and ZnL₂(py) (R = Pr, Prⁱ, Buⁱ) have also been obtained. Basic complexes ZnO,3ZnL₂ (R = Et, Pr) have been isolated. Molecular weight data show that ZnL₂ associates in benzene. When R = Prⁱ 2ZnL₂ ↔ Zn₂L₄ ΔG⁰c -6kJ mol^-1 The adducts ZnL₂(py) are stable. Adducts ZnL₂(py)₂ dissociate in benzene; when R = Pr ZnL₂(py) + PY + ZnL₂(py)₂ ΔG⁰c-7kJmol^-1 (ΔG⁰ calculated from molal concentrations). Infrared data cannot distinguish between chelate, bridging, and unidentate PS₂ groups. Co-crystallization of ZnL₂(py)₂ and XiL₂(py)₂ could not be achieved, suggesting ZnL₂(py)₂ is cis-octahedral.