Structural diversity in the borohydrido lanthanides series: First isolation and X-ray crystal structure of ionic image

The reaction of image with a half equivalent of image image) affords a compound comprising one image ligand and three THF molecules per two Sm atoms, image, according to analytical data. Crystals of penta-THF adduct 1, showing the same 1H NMR spectrum except for the quantity of THF, could be isolated from a solution of half-samarocene image (2). X-ray structure determination of 1 revealed an ionic compound image with two discrete mononuclear Sm polyhedrons. The expected neutral samarocene image(3) could be obtained from the reaction of image with two equivalents of image. X-ray structure analysis showed that 3 is a monomeric complex bearing a terminal borohydride ligand. All image ligands in 1 and 3 exhibit an image bonding mode.