Palladium(II) complexes of tridentate chalcogenated Schiff bases and related ligands of (S, N, S/Se/Te) type: Synthesis and structural chemistry

The reactions in CH3CN between PdCl2 and Schiff base ligands, 2-MeSC6H4-CH=NCH2CH2E-C6H4-4-R (L1-L3) (E = S or Se, R = H; E = Te, R = OCH3) and their reduced derivatives 2-MeSC6H4CH2-NHCH2CH2E-C6H4-4-R (L4-L6) followed by treatment with AgPF6 or AgClO4 have resulted in complexes [PdCl(L)][ X] (1-6; L = L1-L6; X = PF6 or ClO4) which have been characterized by IR, H-1, C-13{H-1}, Se-77{H-1} and Te-125{H-1} NMR spectroscopy. Single crystal structures of complexes 1-6 reveal nearly square planar geometry around palladium in all of them (Pd-Se = 2.4045(16)-2.4065(6) angstrom; Pd-Te = 2.5052(9)-2.5307(13) angstrom). The various non-covalent interactions in the crystals result in the formation of chains, rings and caging of anions between cations. (C) 2012 Elsevier B.V. All rights reserved.