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

Six Mo(IV)-Cu(II) complexes, Cu(tpa)[Mo(CN)(8)]·15H(2)O (1, tpa = tris(2-pyridylmethyl)amine), Cu(tren)[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)Mo(CN)(8)·12.5H(2)O (4, bapa = bis(3-aminopropyl)amine), Cu(bapen)[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)Mo(V)(CN)(8) (7) was synthesized as a model of the photoinduced intermediate.