Synthesis, characterization, and photoresponsive properties of a series of Mo(IV)-Cu(II) complexes

Six Mo(IV)-Cu(II) complexes, Cu(tpa)](2)Mo(CN)(8)]·15H(2)O (1, tpa = tris(2-pyridylmethyl)amine), Cu(tren)](2)Mo(CN)(8)]·5.25H(2)O (2, tren = tris(2-aminoethyl)amine), Cu(en)(2)]Cu(0.5)(en)]Cu(0.5)(en)(H(2)O)]Mo(CN)(8)]·4H(2)O (3, en = ethylenediamine), Cu(bapa)](3)Mo(CN)(8)](1.5)·12.5H(2)O (4, bapa = bis(3-aminopropyl)amine), Cu(bapen)](2)Mo(CN)(8)]·4H(2)O (5, bapen = N,N'-bis(3-aminopropyl)ethylenediamine), and Cu(pn)(2)]Cu(pn)]Mo(CN)(8)]·3.5H(2)O (6, pn = 1,3-diaminopropane), were synthesized and characterized. Single-crystal X-ray diffraction analyses show that 1-6 have different structures varying from trinuclear clusters (1-2), a one-dimensional belt (3), two-dimensional grids (4-5), to a three-dimensional structure (6). Magnetic and ESR measurements suggest that 1-6 exhibit thermally reversible photoresponsive properties on UV light irradiation through a Mo(IV)-to-Cu(II) charge transfer mechanism. A trinuclear compound Cu(II)(tpa)](2)Mo(V)(CN)(8)](ClO(4)) (7) was synthesized as a model of the photoinduced intermediate.