Structural insight into the different reactivities towards ligand S-ethylation with iodoethane of the tetrahedral zinc(II) complexes of 1,1,5,5-tetramethyl-2-thiobiuret and 1,1,5,5-tetramethyl-2,4-dithiobiuret

The crystal structures of the tetrahedral zinc(II) complexes of 1,1,5,5-tetramethyl-2-thiobiuret, Zn(L1)2 (1), and 1,1,5,5-tetramethyl-2,4-dithiobiuret, Zn(L2)2 (2), are reported. The structural differences between the two complexes relating to the zinc coordination environment and the ligand framework are discussed in general, but also with specific regard to the greater observed reactivity of 2 than 1 towards ligand S-ethylation with iodoethane.