Hydrogen-bonded systems between monocarboxylic acids and the trinuclear cluster cation [H3Ru3(C6H6)(C6Me6)2(O)]+: cold-spray ionisation mass spectroscopic and X-ray crystallographic studies

The hydrogen-bonded systems formed between monocarboxylic acid derivatives and the trinuclear arene-ruthenium cluster cation [H3Ru3(C6H6)(C6Me6)2(O)]+ (1) have been studied in solution by cold-spray ionisation mass spectroscopy (CSI-MS) and in the solid state by single-crystal X-ray structure analysis of the tetrafluoroborate salts. The presence of 1:1 (acid:cluster) adducts in acetone solution has been clearly demonstrated by CSI-MS. Single-crystal X-ray structure analyses of selected acid-cluster complexes show that in every case the hydroxyl of the acid function interacts strongly with the μ3-oxo ligand of cation 1, the O ⋯ O distance ranging from 2.499(9) to 2.595(11) Å.