BIS[HYDROTRIS(PYRAZOLYL)BORATO]DICHLOROACTINIDE(IV) COMPLEXES - X-RAY CRYSTAL-STRUCTURES OF THCL2(HBPZ3)2 AND UCL2(HBPZ3)2

The crystal and molecular structures of ThCl2(HBPz3)2 (1) and UCl2(HBPz3)2 (2) have been determined by single-crystal X-ray diffraction. The crystals of 1 are orthorhombic, Pbca, a = 14.406(2), b = 18.523(3), c = 18.947(4) Å, V = 5055.9 Å3 and Z = 8. The crystals of 2 are triclinic, P1, a = 13.134(2), b = 14.481(3), c = 17.030(2) Å, α = 75.72(2), β = 75.08(2), γ = 68.20(2)°, V = 2864.3 Å3 and Z = 4. The actinide centre in both compounds is eight-coordinate and displays square antiprismatic geometry, distorted towards bicapped trigonal prismatic, with the thorium compound presenting a higher distortion relative to the uranium compound. © 1990.