Crystal structure of a 1∶2∶1 packing complex formed by bis(isothiocyanato) tetrakis(pyridine) nickel(II), triphenylmethane, and metanol

Abstract

The structure of the [NiPy4(NCS)2]·2(C6H5)3CH·CH3OH (Py is pyridine) packing complex was determined by single crystal X-ray diffraction analysis (KM-4 diffractometer, λMoKα, graphite monochromator, ω/2ϑ scan mode, θmax, 2073 reflections, R=0.059). The unit cell is base-centered monoclinic, space group C2/c, a=20.22(1), b=14.256(7), c=18.836(6) A, β=87.40(4)°, Z=4C61H56N6NiOS2, dcalc=1.239 g/cm3. The structure is of the island type and consists of molecules of three types. In the trans-[NiPy4(NCS)2] molecule, the central atom has a distorted octahedral environment and is coordinated by six nitrogen atoms of two isothiocyanate and four pyridine ligands. In contrast to the phase of the complex itself, this molecule acquires a four-lobe propeller conformation, in which the pyridine rings are rotated relative to the equatorial plane by angles of 52.8(3) and 50.1(2)°. The triphenylmethane molecule has a three-lobe propeller conformation, as in triphenylmethane clathrates with benzene, thiophene, pyrrole, and aniline, but strongly deviates from threefold axis symmetry. The phenyl rings form dihedral angles of 25(3), 40(4), and 19(4)° with the planes formed by the bonds of the ternary carbon atoms with hydrogen atoms and by the appropriate carbon atom of the phenyl ring. The methanol molecules are located inside the direct channels running along the c axis and are disordered around the inversion centers.