Bifunctional materials based on the photochromic cation [RuNO(NH3)5)3+ with paramagnetic metal complex anions

The synthesis of a series of compounds containing the photochromic mononitrosyl cation, [RuNO(NH3)(5)](3+) and metal complex paramagnetic anions [M(CN)(6)](3-) [M = Cr (1), Fe(2)], [M(ox)(3)](3-) [M = Cr(3), Fe(4)] and [CrNO(CN)(5)](3-) (5) is reported. The crystal structures of the salts 1 and 3 are discussed. In contrast to 1 and 3 which exhibit reversible photochromic properties, illumination of 2 and 4 results in an irreversible photochemical reaction and compound 5 is not photochromic at all. The magnetic properties of 1 and 3 have been investigated and complex 1 shows a weak reversible increase in the value of chi T-M under light irradiation at low temperature. (c) Wiley-VCH Verlag GmbH & Co.