Structure of trans-chloronitrosyltetrakis(pyridine)ruthenium(II) bis(hexafluorophosphate) hemihydrate

[Ru(py)4Cl(NO)](PF6)2·0.5H2O: a model system for structural determination and ab initio calculations of photo-induced linkage NO isomers

“…In accordance with Kimura et al (1983) the Ru-N-O linkage is linear with distances of Ru1-N5 = 1.7550 (17), Ru2-N10 = 1.7537 (16), N5-O5 = 1.146 (2), N10-O10 = 1.147 (2) Å and angles of Ru1-N5-O5 = 178.96 (6) , Ru2-N10-O10 = 175.47 (6) , which is in the range of all known {RuNO} 6 compounds (Enemark & Feltham, 1974) with formally Ru II and NO + . The pyridine rings show a propellerlike structure as follows from the torsion angles in Table 3.…”

“…Especially the quality of structural determinations for populations less than 50%, which include many necessary constraints, are discussed. The ground-state structure of [Ru(py) 4 Cl(NO)]-(PF 6 ) 2 Á0.5H 2 O was determined earlier by Kimura et al (1983), yielding an R value of wR (all) = 0.0551 without refining H atoms. As a further important result we present DFT calculations on the ground and metastable states SI and SII of the solid state, which show the high level of accuracy that can be reached nowadays for the prediction of structures.…”

Photogeneration of two metastable NO linkage isomers with high populations of up to 76% in trans-[RuCl(py)4(NO)][PF6]2·½H2O

“…Furthermore, we note that the splittings of the n(NO) vibrations indicate the influence of the environment or of nonequivalent crystallographic positions on the NO moiety. The crystallographic unit cell contains 8 molecules on two crystallographically inequivalent sites, 37 such that a splitting into a doublet could be expected. However the three n(NO) bands in the GS and the four bands in SI indicate a further splitting.…”

“…Since the crystal structure of trans-[RuCl(py) 4 (NO)]-[PF 6 ] 2 Á 1 2 H 2 O is known, 37 we can compare it to the calculated GS, thereby obtaining a criterium for the reliability of the calculated metastable structures of SI and SII (see Table 3). However, the calculation is performed for the free trans-[RuCl(py) 4 )NO] 2+ cation.…”

Synthesis and characterization of trans-[Ru(NO)Cl(L)4](PF6)2 (L = isonicotinamide; 4-acetylpyridine) and related species

“…This py complex has a trans configuration according to X-ray diffraction studies [11]; the four equatorial pyridines form a propeller-like arrangement with an average pitch of about 46 . It was suggested that rapid cogwheel rotation of the pyridine rings about the Ru-N(py) axis is occurring in solution, which would explain the three aromatic ring H's NMR signals instead of five for trans-[Ru(NO)Cl(py) 4 ](PF 6 ) 2 Á ½H 2 O [11]. Since, trans-[Ru(NO)(OH)(py) 4 ] 2+ has the same trans configuration [12], it is reasonable to expect the same NMR pattern.…”