Synthesis, crystal structure and properties of bis-(iso-seleno-cyanato-κ)tetra-kis-(4-meth-oxy-pyridine-κ)cobalt(II).

Reaction of CoCl·6HO with KNCSe and 4-meth-oxy-pyridine in water led to the formation of the title compound, [Co(NCSe)(CHNO)] or Co(NCSe)(4-meth-oxy-pyridine), which was characterized by single-crystal X-ray diffraction. Its asymmetric unit consists of one crystallographically independent Co cation, two seleno-cyanate anions and four 4-meth-oxy-pyridine coligands in general positions. In the crystal structure, the cobalt cations are sixfold coordinated by two terminal N-bonded seleno-cyanate anions and four 4-meth-oxy-pyridine coligands within a slightly distorted octa-hedral coordination. Between the complexes, weak C-H⋯Se inter-actions are found. IR spectroscopic investigations revealed that the CN stretching vibration of the anionic ligands is observed at 2068 cm, which is in agreement with the presence of only terminally coordinated seleno-cyanate anions. PXRD measurements prove that a pure compound was obtained. Differential thermoanalysis coupled to thermogravimetry (DTA-TG) at different heating rates shows that the TG curves are poorly resolved. PXRD measurements of the residue obtained by a TG measurement prove that an amorphous compound was obtained.