SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF THE FIRST LANTHANIDE TRIS(PHOSPHIDO) COMPLEX - TM[P(SIME(3))(2)](3)THF)(2)

Tml(3)(thf)(x) (x = 3.5) reacts with 3 equiv, of KP(SiMe(3))(2) in thf at room temperature to form an orange suspension from which trivalent Tm[P(SiMe(3))(2)](3)(thf)(2), 1, can be isolated in 60% yield (monocl inic, space group C2/c, four molecules in the unit cell); the structur e of 1 features the five-coordinate thulium atom in a distorted trigon al bipyramidal environment with two thf molecules in the axial and the bis(trimethylsilyl)phosphido ligands in the equatorial positions.