Synthesis of di- and tetranuclear oxidomolybdenum (V) complexes containing p-toluenesulfonates as ligands: a joint spectroscopic, crystallographic and computational study

The 1 : 1 reaction of MoCl5 with 1,4-Me(SO3Me)C6H4 led to the isolation of crystalline Mo2O2Cl6[μ–κ2- 1,4-Me(SO3Me)C6H4], 1, in low yields. Attempts to reproduce the synthesis of 1 from MoOCl3/1,4-Me (SO3Me)C6H4 resulted in the good-yield formation of [MoOCl2(μ-Cl)(κ1-1,4-Me(SO3Me)C6H4)]2, 2. The 1 : 1 reaction of MoCl5 with 1,4-Me(SO3H)C6H4·H2O selectively yielded Mo4O4Cl8[μ3-1,4-Me(SO3)C6H4]4, 3. Compounds 1 and 3 were characterized by X-ray diffractometry; moreover DFT calculations were carried out on 1–3 in order to shed light on their thermodynamic and structural features.