Crystal structure of trans- and cis-bis(acetylacetonato)bis(trimethylphosphite)ruthenium(II) complexes and testing their catalytic activity in hydrogen generation from the hydrolysis of sodium borohydride

Both the trans and cis isomers of [Ru(acac)2{P(OMe)3}2] were isolated in the form of single crystals and characterized by single crystal X-ray diffraction, UV–Vis, MS, 1H, 13C and 31P NMR spectroscopy. The compounds of ruthenium(II), both mononuclear complexes, crystallize in triclinic P1¯ space group. The metal ion in both compounds has similar, slightly distorted octahedral coordination geometry. Both complexes were tested as catalyst in hydrogen generation from the hydrolysis of sodium borohydride. When used alone, none of the trans- and cis-[Ru(acac)2{P(OMe)3}2] complexes shows significant catalytic activity. However, the catalytic activity of cis-[Ru(acac)2{P(OMe)3}2] in the hydrolysis of sodium borohydride is significantly enhanced by the addition of two equivalents of trimethylphosphite per ruthenium into the medium.

Graphical abstractThe trans- and cis-[Ru(acac)2{P(OMe)3}2] were characterized by single crystal X-ray diffraction, UV–Vis, MS, 1H, 13C and 31P NMR spectroscopy and tested as homogeneous catalysts in hydrolysis of sodium borohydride. Catalytic activity of the cis isomer is radically enhanced in the presence of two equivalents of trimethylphosphite showing formation of new ruthenium species which has more than two phosphorus ligands.Figure optionsDownload full-size imageDownload as PowerPoint slide