ChemInform Abstract: THE LEWIS‐ACIDITY OF SQUARE‐PLANAR NICKEL(II) COMPLEXES. I. A KINETIC AND THERMODYNAMIC STUDY OF THE REACTION OF BIS(O,O‐DIETHYL PHOSPHORODITHIOATO‐S,S′‐)NICKEL(II) WITH BIDENTATE NITROGEN DONORS

Abstract

The kinetics of the addition reaction between bis(O,O-diethyl phosphorodithioato-S,S'-)nicke1(11) and a series of bidentate nitrogen ligands has been examined by stopped-flow techniques. The reactions are first order in ligand and nickel complex with kf, the second-order rate constant, in the range from 103 to 106 1. mol-1 s-1 at 25oC in benzene. Solvent effects on the reaction with 2,2'-bipyridyl are minor. The variation in kf with ligand is discussed in terms of the steric requirements of the ligands, the bulkiest ligand, 2,9-dimethyl-1,l0-phenanthroline, reacting most slowly. For the ligands 1,l0-phenanthroline and 2,2'-bipyridyl in the more polar solvents, successive displacement of the thiophosphate ligands follows the initial addition step.