Tellurium-Ligated Pd(II) Complex of Bulky Organotellurium Ligand as a Catalyst of Suzuki coupling: First Report on In Situ Generation of Bimetallic Alloy ‘Telluropalladinite’ (Pd9Te4) Nanoparticles and Role in Highly Efficient Catalysis

A novel, easily synthesizable, air and moisture insensitive organotellurium ligand L1 and its Pd(II) complex (i.e., 1) Pd(L1)Cl2] (L1: pyren-1-yl-CH=N–(CH2)2TePh] have been synthesized. Both L1 and 1 have been characterized using 1H, 13C and 125Te NMR spectroscopy. Mass spectrometric and single crystal X-ray diffraction techniques have also been used to corroborate the structure of the Pd(II)-complex in which ligand is coordinated with palladium in bidentate (Te, N) mode. The Pd(II) complex has been explored as a catalyst for Suzuki–Miyaura coupling reaction. During the course of catalysis, it dispenses the nanoparticles of palladium rich alloy ‘telluropalladinite’ (Pd9Te4). Among catalytically active Te/Se/S-ligated complexes studied during preceding 20 years, it shows an extremely high efficiency (TON values: upto 107 for coupling reactions of ArBr). It has also been found competent enough to catalyze the reactions of least reactive ArCl within 3 h.