Figure 2.

(a) Hydrolysis–dehydration chemical reaction for Zn oxo cluster formation (reprinted with permission from ref. [23], 2012, Royal Society of Chemistry). (b) Structure of tin oxo clusters (reprinted with permission from ref. [21], 2014, Elsevier). (c) Photochemical reactions for $\mathrm{T}\mathrm{i}\mathrm{n}\mathrm{O}\mathrm{H}$ subjected to UV in air and ${\mathrm{N}}_2$ [22].