New cyclometalated palladium(II) complexes with iminophosphines crystal structures of [Pd(CXN)(o-Ph2PC6H4-CH=NR)][PF6] (CXN=azobenzene, R=Et; CXN=2-phenylpyridine, R=Me)

The synthesis of new cyclometalated compounds of palladium(Il) with the mixed-donor bidentate ligands o-Ph2PC6H4-CH=NR is described. Two series of complexes [Pd(CxN)(o-Ph2PC6H4-CH=NR)][PF6] have been prepared using either azobenzene or 2-phenylpyridine as cyclometalated ligands [CxN=azobenzene (azb); R=Me (1a), Et (2a), " Pr (39), 'Pr (4a), 'Bu (5a), Ph (6a), NH-Me (7a); CxN=2-phenylpyridine (phpy); R=Me (Ib), Et (2b)," Pr (3b),'Pr (4b),'Bu (5b), Ph (6b), NK-Me (7b)]. The new complexes were characterized by partial elemental analyses and spectroscopic methods (IR, FAB,H-1 and P-31 NMR). The molecular structures of compounds 2a (monoclinic, P 2(1)/n) and Ib (monoclinic, C 2/c) have been determined by a single-crystal diffraction study. In both cases this technique revealed the relative trans configuration between the phosphorus atom and the nitrogen atom of the ortho-metalated ligand. (C) 1999 Elsevier Science Ltd. All rights reserved.