Bismuth and antimony halometalates containing photoswitchable ruthenium nitrosyl complexes.

The first examples of Bi(III) and Sb(III) halide compounds combined with a photoswitchable ruthenium nitrosyl unit are reported. The structures of [RuNOPyBr][SbBr][SbBr] (1) and (HO)[RuNOPyBr][BiBr]·3HO (2) were determined by X-ray diffraction, and exhibit three different structural types of group 15 halometalates. Low-temperature IR-spectroscopy measurements reveal that the irradiation of 1 at 365 nm switches a stable Ru-NO (GS) unit to a metastable Ru-ON (MS1) linkage. Moreover, the light excitation of 2 at 365 or 405 nm induces the additional formation of a side-bond isomer Ru-η-(NO) (MS2). The reverse reactions MS1/MS2 → GS can be induced by red-infrared light irradiation or by heating at temperatures >200 K. The obtained synthetic and spectroscopic data open the way for the preparation of hybrid halide complexes with a variety of photoswitchable complexes (NO, SO, N, .), and give an insight into the behavior of light-induced species embedded in polynuclear halides.