Tetraphenylphosphonium](1+) {3,3′-commo-bis-[η5-1,2-dicarba-(3)-nickel(III)-closo-dodecaborate]}(1−)-monotetrachloromethanate, [(C6H5)4P]+{Ni3+[η5-(3)-1,2-B9C2H11]2}− · CCl4: Synthesis, structure, and temperature-dependent EPR spectra

Abstract

A novel compound containing tetraphenylphosphonium and nickel dicarbollyl, [[P(C6H5)4][Ni(B9C2H11)2] · CCl4 (I) was synthesized and studied by X-ray diffraction and EPR methods. The crystals are monoclinic: C29H42B18PCl4Ni (M = 816.69), space group P2/c, the unit cell parameters a = 13.3964(5), b = 7.0556(2), c = 20.6610(8) A, β = 94.9070(13)°, V = 1945.7(2) A3, Z = 2, ρ(calcd.) = 1.394 g/cm3, T = 100 K, F(000) = 834, μ = 0.081 mm−1. The structure was solved by the direct and Fourier methods and refined by the full-matrix least-squares method in the anisotropic (isotropic for the hydrogen atoms) approximation (R1 = 0.032 for 4027 Ihkl ≥ 2σ(I), 19886 measured and 5379 independent Ihkl; X8 APEX Bruker difractometer, λMoKα, graphite monochromator, ϕ/ω scan mode). At 100 K, the crystal contains the intermolecular hydrogen bonds B–H…Cl that favor the formation of infinite chains of the alternating anions and solvate molecules along the z axis of the unit cell. The single-crystal EPR study of complex I showed that the temperature changes of the cell parameters induce changes in the parameter of the g-factor g1 directed along Cb-Ni-Cb. The cell parameters are increased and the g1 value is gradually decreased with the increasing temperature. The temperature study of the EPR spectra of the powdered compound I revealed also jumpwise changes in g2 and g3 with hysteresis at 183–203 K depending on the direction of the temperature changes. The differences observed in the EPR spectra of the powders and single crystal of compound I in both the g-factor and the temperature dependence of its components are supposed to be caused by the CCl4 vacancies formed in the crystal structure of a complex as a result of the partial removal of the solvate CCl4 molecules when grinding the sample and by the change in the lability of the solvate molecules of a solvent with temperature.