Bridge Cleavage Reactions of Dinuclear Diselenolenes: Preparation of Palladium Complexes of Novel Chelating Selenolato/Selenide Ligands, [PdX(Se{R′}C_nH_2n−4Se)(PR₃)](n = 6, 7, 8; R = Ph, Bu; X = Br, I; R′ = Me, Et, etc.)

Abstract

The dinuclear palladium diselenolenes [Pd 2 (Se 2 C n H 2n−4 ) 2 (PR 3 ) 2 ] react with haloalkanes, via electrophilic attack at the bridging selenium atoms, to yield the neutral mononuclear square planar palladium(II) complexes [PdX(Se{R }C n H 2n−4 Se)(PR 3 )] (n = 6, 7, 8; R = Ph, Bu; X = Br, I; R = Me, Et, etc.), containing a novel chelating selenolato/selenide ligand, in which the alkylated selenium and halogen donor atoms occupy cis-positions. The products have been characterised by mass spectrometry and multinuclear NMR spectroscopy; the molecular structure of the compound with n = 8, R = Ph, R = Et has been determined by X-ray crystallography.