Platinum(II), palladium(II), nickel(II), and gold(I) complexes of the “electrospray-friendly” thiolate ligands 4-SC5H4N− and 4-SC6H4OMe−

Abstract

The series of platinum(II), palladium(II), and nickel(II) complexes [ML2(dppe)] [M = Ni, Pd, Pt; L = 4–SC5H4N or 4–SC6H4OMe; dppe = Ph2PCH2CH2PPh2] containing pyridine-4-thiolate or 4-methoxybenzenethiolate ligands, together with the corresponding gold(I) complexes [AuL(PPh3)], were prepared and their electrospray ionization mass spectrometric behavior compared with that of the thiophenolate complexes [M(SPh)2(dppe)] (M = Ni, Pd, Pt) and [Au(SPh)(PPh3)]. While the pyridine-4-thiolate complexes yielded protonated ions of the type [M + H]+ and [M + 2H]2+ ions in the Ni, Pd, and Pt complexes, an [M + H]+ ion was only observed for the platinum derivative of 4-methoxybenzenethiolate. Other ions, which dominated the spectra of the thiophenolate complexes, were formed by thiolate loss and aggregate formation. The X-ray crystal structure of [Pt(SC6H4OMe–4)2(dppe)] is also reported.