Heteroleptic Complexes of Ruthenium Nitrosyl with Pyridine and Bypiridine-Synthesis and Photoisomerization.

ABSTRACT: The reaction of [RuNO(Py)₂Cl₂OH] with bipyridine in water-ethanol media results in trans-(NO, OH)-[RuNO(Py)(Bpy)ClOH]⁺ with an acceptable yield (60-70%) as hexafluorophosphate salt. Further treatment of the hydroxy-complex with concentrated HF quantitatively leads to trans-(NO, F)-[RuNO(Py)(Bpy)ClF]⁺. Despite the chirality of both coordination spheres, the hexafluorophosphate salts crystallized as racemates. A NO-linkage isomerism study of the obtained complexes was performed at 80 K with different excitation wavelengths (405, 450, 488 nm). The most favorable wavelengths for the MS1 isomer (Ru-ON) formation were 405 and 450 nm, where the linkage isomer populations were 17% and 1% for [RuNO(Py)(Bpy)ClOH]PF₆ and [RuNO(Py)(Bpy)ClF]PF₆. The shift of the excitation wavelength to the green (488 nm) sharply decreased the MS1 population. The IR-spectral signatures of MS1 were registered. Reverse-transformation Ru-ON (MS1)-Ru-NO (GS) was investigated for [RuNO(Py)(Bpy)ClOH]PF₆ using IR and DSC techniques that made it possible to determine the kinetic parameters (E_a and k₀) and decay temperature.

SUBMITTER: Brovko AO 

PROVIDER: S-EPMC11397342 | biostudies-literature | 2024 Aug

REPOSITORIES: biostudies-literature