[Tetraphenylphosphonium](1+){3,3'-commo-bis-[eta~5-1,2-dicarba-(3)-nickel(III)-closo-dodecaborate]}(1-)-mono-tetrachloromethanate,[(C6H5)4P]~+{Ni~(3+)[eta~5-(3)-1,2-B9C2H_(11)]2}~-·CCl4:Synthesis,Structure,and Temperature-Dependent EPR Spectra

摘要

A novel compound containing tetraphenylphosphonium and nickel dicarbollyl,[[P(C6H5)4][Ni(B9C2H_(11))2]·CC14(I)was synthesized and studied by X-ray diffraction and EPR methods.The crystals are monoclinic:C_(29)H_(42)B_(18)PCl4Ni(M=816.69),space group P2/c,the unit cell parameters a=13.3964(5),b=7.0556(2),c=20.6610(8)A,beta=94.9070(13)°,V=1945.7(2)A~3,Z=2,p(calcd.)=1.394 g/cm~3,T=100 K,F(000)=834,mu=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 I_(hkl)>=2 sigma(7),19886 measured and 5379 independent I_(hkl);X8 APEX Bruker difrac-tometer,lambda MoK_(alpha),graphite monochromator,phi/omega 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 g2and 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.