Variable Bonding Modes of Pyrimidine‐2‐thione in Pd II /Pt II Complexes [M(η 2 ‐N, S‐pymS)(η 1 ‐S‐pymS)(PPh 3 )] and [M(η 1 ‐S‐pymS) 2 (L‐L)] (L‐L = dppm, dppe)

Reactions of pyrimidine‐2‐thione (HpymS) with Pd II /Pt IV salts in the presence of triphenyl phosphine and bis(diphenylphosphino)alkanes, Ph 2 P‐(CH 2 ) m ‐PPh 2 (m = 1, 2) have yielded two types of complexes, viz. a) [M(η 2 ‐N, S‐ pymS)(η 1 ‐S‐ pymS)(PPh 3 )] (M = Pd, 1 ; Pt, 2 ), and (b) [M(η 1 ‐S‐pymS) 2 (L‐L)] {L‐L, M = dppm (m = 1) Pd, 3 ; Pt, 4 ; dppe (m = 2), Pd, 5 ; Pt, 6 }. Complexes have been characterized by elemental analysis (C, H, N), NMR spectroscopy ( 1 H, 13 C, 31 P), and single crystal X‐ray crystallography ( 1 , 2 , 4 , and 5 ). Complexes 1 and 2 have terminal η 1 ‐S and chelating η 2 ‐N, S‐modes of pymS − , while other Pd/Pt complexes have only terminal η 1 ‐S modes. The solution state 31 P NMR spectral data reveal dynamic equilibrium for the complexes 3 , 5 and 6 , whereas the complexes 1 , 2 and 4 are static in solution state.