metal-organic compounds
Open access
The title complex, [Co(C21H16N4)2][Co(NCS)4]·CH3OH, consists of one [Co{C(py)4}2]2+ complex cation [C(py)4 = tetrakis(pyridin-2-yl)methane], one [Co(NCS)4]2− complex anion and a methanol solvent molecule. In the cation, the CoII atom is coordinated by six N atoms of two C(py)4 ligands in a distorted octahedral geometry. In the anion, the CoII atom is coordinated by the N atoms of four NCS− ligands in a distorted tetrahedral geometry. The methanol molecule is disordered and was modelled over three orientations (occupancies 0.8:0.1:0.1). There are two weak hydrogen-bond-like interactions between the methanol solvent molecule and NCS− ligands of the anion [OS = 3.283 (3) and 3.170 (2) Å].
data reports
Open access
A second polymorph of the title compound, C21H16N4, is reported. The original polymorph was solved by our group [Matsumoto et al. (2003). Tetrahedron Lett. 44, 2861-2864] in the monoclinic space group C2/c and refined to R = 0.050. Now the crystal structure of a tetragonal polymorph (space group P-421c) has been solved and refined to R = 0.036. In the crystal, there are no strong intermolecular interactions. Reflecting the high symmetry of the molecular structure, the asymmetric unit is a quarter of the molecule, and the molecule exhibits S4 symmetry along the c axis in the crystal.