Hybrid Inorganic‐Organic Photochromic Film Based on Polymolybdate and Isoniazid Dimer: Synthesis, Structure, and Photochromism.

A photochromic film based on an inorganic‐organic hybrid, Na3H(H2O)2[β‐Mo8O26](C12H8N4O2)2·19H2O (1), is developed for the first time. Compound 1 was in situ synthesized and structurally characterized by single‐crystal X‐ray crystallography, and a dimerization reaction of isoniazid can be directly observed during the synthesis process. Together with the polymolybdate, the azo bond in the dimerization product N,N'‐bis(isonicotinamide) hydrazide showed photochromic properties under illumination, widening the light absorption range of polymolybdate. Irradiation experiments of the prepared film indicated an excellent waterproof and recyclable layered material, which demonstrated a distinctive way of extending the application of polyoxometalate based hybrid inorganic‐organic functional materials in the field of photocatalysis. [ABSTRACT FROM AUTHOR]