Heterometallic Mo–Ti oxo clusters with metal–metal bonds: Preparation and visible-light absorption behaviors

In this work, two heterometallic clusters, namely Ti^IV₄Mo^V₄Mo^VI₂O₁₆(OCH₃)₁₆ (1) and Ti^IV₄Mo^V₄O₁₀(OC₂H₅)₁₄ (C₆H₅COO)₂ (2) are successfully constructed to improve the solar absorption and performance of titanium oxo clusters (TOCs). The 1 and 2 structures are determined well by single-crystal X-ray diffraction analysis and found to feature the common presence of Mo–Mo interactions. The solid-state UV–vis absorption studies indicate that these structures exhibit enhanced visible-light absorption and significantly reduced optical band gaps, which should be dominantly attributed to the introduction of electron-rich Mo–Mo pairs as heterometals. This work demonstrates an effective strategy of regulating the light absorption behaviors of TOCs by importing electron-rich heterometals.