Bis(eta(5)-isopropyltetramethylcyclopentadienyl)(tetrahydroberato-kappa(3)H,H ',H '')(tetrahydrofuran-O)-samarium(III): a lanthanidocene complex with a tridentate tetrahydroborato ligand

The lanthanidocene complex [Sm(BH4)(C12H19)(2)(C4H8O)], (I), shows a distor ted tetrahedral arrangement around the central Sm-III atom. It consists of two eta(5)-isopropyltetramethyl-cyclopentadienyl ligands, one tetrahydrobor ato (BH4-) ligand bridging via H atoms to the lanthanide atom and one coord inating tetrahydrofuran (thf) molecule. The BH4- unit of (I) coordinates as a tridentate ligand with three bridging H atoms and one terminal H atom [S m-B-H4 176 (2)degrees]. The eta(5)-isopropyltetramethylcyclopentadienyl lig ands of this bent-sandwich complex [Cp1-Sm-Cp2 133.53(1)degrees where Cp de notes the centroid of the cyclopentadienyl ring] adopt staggered conformati ons.