{RuII(NO+)}3+-core complexes with 4-methyl-pyrimidine and ethyl-isonicotinate: Synthesis, X-ray structure, spectroscopy, and computational and NO-release studies upon UVA irradiation

The reaction of RuCl3(NO) · H2O with 4-methylpyrimidine (MePYM) and ethylisonicotinate (EINT), in absolute ethanol at 40-55 °C afforded crystalline trans-[RuCl3(NO)L2] complexes. Structural studies via X-ray diffraction, and spectroscopic methods (NMR, IR, UV-visible (UV-Vis)) revealed that the molecular structures have the two Ls in trans positions (axial) and the chloride anions and the NO+ cation as equatorial ligands; pyrimidine⋯pyrimidine pairing pattern via two weak C-H⋯N interactions occur. The molecular structures for the EINT derivative was inferred from spectroscopy and computations. Under irradiation at 366 nm several solutions of the title compounds deliver NO via first order processes. Visible light (420-700 nm) does not produce significant NO release from CH2Cl2 and CH3CN solutions within 24 h.