X-Ray diffraction and spectroscopic studies of the light-induced metastable state of a ethylenediamine nitrosyl ruthenium complex

摘要

Blue-laser irradiation of a single crystal of the chloride salt of a cationic complex, trans-[Ru(en)(2)(H2O)(NO)](3+) (en=ethylenediamine), yielded MS1 (a metastable state of end-on type) which is remarkably stable (decay temperature T-d=267 K) compared with MS1 of sodium nitroprusside Na-2[Fe(CN)(5)(NO)] (SNP). No MS2 state (side-on type) was observed by X-ray diffraction and IR spectroscopy. Even with a low population of 8% of the metastable species, the structure was clearly determined by X-ray analysis. For the first time, we observed an elongation of the N-O bond by X-ray diffraction, corresponding to a frequency downshift of the nu(NO) stretching vibration. The remarkably long lifetime of the metastable state of trans-[Ru(en)(2)(H2O)(NO)](3+) compared with that of SNP is explained by a stereochemical analysis using reaction cavity diagrams. [References: 45]