Tuning the nuclearity of [Mo2O2S2]2+-based assemblies by playing with the degree of flexibility of bis-thiosemicarbazone ligands

MoV2 O2S(2)] (2+)-based thiosemicarbazone complexes appear as very promising molecules for biological applications due to the intrinsic properties of their components. This paper deals with the synthesis and characterization of six coordination complexes obtained by the reaction of [MoV2 O2S(2)](2+) clusters with bisthiosemicarbazone ligands that contain flexible or rigid spacers between the two thiosemicarbazone units. Interestingly, structural characterization by single-crystal X-ray diffraction, MALDI-TOF MS technique and NMR spectroscopy revealed that the nuclearity of the complex is controlled by the nature of the spacer between the thiosemicarbazone units. Binuclear complexes, namely [MoV2 O2S2(L1-3 )], are isolated with flexible spacers while tetranuclear complexes [(MoV2 O2S2)(2)(L4-6)(2)] are formed when the bisthiosemicarbazone ligands are built on rigid spacers.

Automated summary

This paper reports the synthesis and characterization of six coordination complexes obtained by reacting [MoV2 O2S(2)](2+) clusters with bisthiosemicarbazone ligands containing flexible or rigid spacers. The nuclearity of the complexes was found to be controlled by the nature of the spacer between the thiosemicarbazone units, as revealed by structural characterization techniques. Flexible spacers resulted in binuclear complexes [MoV2 O2S2(L1-3)], while rigid spacers led to tetranuclear complexes [(MoV2 O2S2)(2)(L4-6)(2)].