Kevin J. Forrestal

Isopropyltetramethylcyclopentadienyl samarium chemistry: structural studies of divalent (C5Me4iPr)2Sm(THF) and mixed valent [(C5Me4iPr)2Sm]2(μ-Cl)

Abstract The isopropyltetramethylcyclopentadienyl samarium complexes (C5Me4iPr)2Sm(THF), 1, and [(C5Me4iPr)2Sm]2(μ-Cl), 2, have been isolated and structurally characterized. Divalent 1 crystallizes from hot toluene as a monosolvate in space group P3121 with a=b=15.494(2) A, c=9.7724(7) A, α=β=90°, γ=120°, V=2031.6(5) A3 and Dcalcd=1.346 g⧹cm3, Z=3 and T=163 K. 1 has a 141.6° ring centroid–Sm–ring centroid angle and an average Sm–C distance of 2.80(3) A. 2 crystallizes from hot toluene in space group P1 with a=9.616(2) A, b=15.479(2) A, c=17.844(1) A, α=111.671(4)°, β=93.488(8)°, γ=107.494(9)°, V=2309.3(5) A3 and Dcalcd=1.423 g⧹cm3, Z=2 and T=163 K. The two bent metallocene units in 2 are connected by an asymmetrical chloride bridge which has a 169.88(4)° Sm(1)–Cl–Sm(2) angle and 2.678(1) A Sm(1)–Cl and 2.891(1) A Sm(2)–Cl distances. The 2.69(2) A average Sm(1)–C(C5Me4iPr) distance is characteristic of Sm(III) and the 2.80(2) A average Sm(2)–C(C5Me4iPr) distance is characteristic of Sm(II).

STRUCTURAL STUDIES OF BRIDGED BIMETALLIC NEODYMIUM AND URANIUM PENTAMETHYLCYCLOPENTADIENYL COMPLEXES: {[(C5Me5)2Nd(THF)l2[μ-Cl}{BPh4} and [(C5Me5)2UCl]2[μ-O]

Abstract The solid state structure of {[C5Me5)2Nd(THF)]2[μ-Cl]}{BPh4} C6H6, 1, consists of a cation with THF-solvated decamethylneodymocene units connected symmetrically by a chloride bridge with 2.839(3) A Nd-(μ-Cl) bonds and a 174.09(10)° Nd-Cl-Nd angle. The {BPH4}-anion is non-coordinating. The structure of [(C5Me5)2UC1]2[μ-O] C7H8, 2, consists of two chloride ligated [(C5Me5]2U] units bridged symmetrically by a single oxide ion with 2.129(5) A U-(μ-O) distances and a 167.1(2)° U-O-U angle. Both complexes have normal metrical parameters in the (C5Me5)2M metallocene units.