Synthesis and crystal structure of dinuclear palladium(I) dppm complex with 4-mercaptopyridine in the thione mode. [Pd 2(μ-dppm) 2(HpyS) 2](ClO 4) 2·CH 3OH

Abstract

The reaction of [Pd 2(μ-dppm) 2] 2 with 4-mercaptopyridine (PySH) in methanol produced the dipalladium(I) dppm complex [Pd 2(μ-dppm) 2(HypS) 2](ClO 4) 2·CH 3OH( 1), and its structure and properties were characterized by a single crystal X-ray structure analysis, UV-Vis, IR and NMR spectra. The two Pd atoms are doubly-bridged by two dppm ligands to form an eight-membered Pd 2P 4C 2 framework, in a twist-chair conformation. The HpyS ligand in the thione mode is also coordinated to each Pd atom, forming the Pd 2P 4C 2 framework in a side-by-side conformation. The average PdS and PdP distance is 2.403 (2) and 2.299(2) Å, respectively. The PdPd distance of 2.6645(6) Å is shorter than that (2.75 Å) in Pd metal, which is indicative of a direct PdPd bond. The results of IR, NMR and UV-Vis spectra supported that the dinuclear structure of 1 is kept in solid and solution.