NMR detection of thermal and photochemical dihydrogen addition products of mono- and tri-nuclear ruthenium complexes containing carbonyl and triphenylphosphine ligands through para-hydrogen induced polarisation

Enhancement of NMR signals by para-hydrogen induced polarisation is shown to facilitate the detection of isomers of Ru(CO)(2)(H)(2)(PPh3)(2) and Ru(CO)(3)(H)(2)(PPh3) which contain inequivalent hydride ligands, and to demonstrate that Ru-3(CO)(9)(PPh3)(3) adds H-2 to form Ru-3(CO)(8)(H)(mu-H)(PPh3)(3), as well as undergoing fragmentation to form Ru(CO)(3)(H)(2)(PPh3).