Polyoxometalate/ s -triazine hybrid heterostructures with ultrafast photochromic properties.

As an emerging class of hybrid complexes, donor-acceptor (D-A) hybrid heterostructures, which combine the advantages of both organic and inorganic photoactive components, provide excellent platforms for the fabrication of photochromic materials with enhanced photo-responsive performances. Herein, four novel hybrid heterostructures, namely H 3 TPT·(PW 12 O 40 )·2NMP (1), (H 1.5 TPT) 2 ·(PW 12 O 40 ) (2), (H 3 TPT) 2 ·(SiW 12 O 40 )·2Cl·2MeCN (3), and H 3 TPT·(HPMo 12 O 40 )·Cl·3NMP (4) (TPT is tri(4-pyridyl)- s -triazine, NMP is N -methylpyrrolidone), have been synthesized and characterized. Benefitting from the strong interactions (anion-π interactions) and matching electron energy levels between the donors and acceptors, some of them exhibited ultrafast photochromic behaviour even up to 1 second. Furthermore, based on experimental and theoretical calculations, the plausible PIET process and structure-activity relationship have been discussed in detail.