Coupling Raman spectroscopy and DFT study for enhanced description of nitrosyl nitrato nitrite ruthenium(III) complexes in nitric acid

Conformation, hydration, and ligand exchange process of ruthenium nitrosyl complexes in aqueous solution: Free-energy calculations by a combination of molecular-orbital theories and different solvent models

Distribution of solvent molecules near transition-metal complex is key information to comprehend the functionality, reactivity, and so forth. However, polarizable continuum solvent models still are the standard and conventional partner of molecular-orbital (MO) calculations in the solution system including transition-metal complex. In this study, we investigate the conformation, hydration, and ligand substitution reaction between NO₂ ^- and H₂ O in aqueous solution for [Ru(NO)(OH)(NO₂ )₄ ]^2- (A), [Ru(NO)(OH)(NO₂ )₃ (ONO)]^2- (B), and [Ru(NO)(OH)(NO₂ )₃ (H₂ O)]^- (C) using a combination method of MO theories and a state-of-the-art molecular solvation technique (NI-MC-MOZ-SCF). A dominant species is found in the complex B conformers and, as expected, different between the solvent models, which reveals that molecular solvation beyond continuum media treatment are required for a reliable description of solvation near transition-metal complex. In the stability constant evaluation of ligand substitution reaction, an assumption that considers the direct association between the dissociated NO₂ ^- and complex C is useful to obtain a reliable stability constant.

Characteristic vibrational frequencies of osmium(ii) nitrosyl complexes probed by Raman spectroscopy and DFT calculations

Raman spectroscopy at variable temperature provides experimental frequencies for osmium(ii) nitrosyl complexes. Vibrational transitions are assigned using DFT calculations.