Synthesis, crystal structure and third-order non-linear optical properties of a cobalt(II) one-dimensional supramolecular compound

A cobalt(II) thiocyanate complex [Co(py)4(NCS)2] 1 (py = pyridine) has been synthesized by low-temperature solid-state reaction. Single crystal X-ray analysis reveals that 1 possesses a one-dimensional (1-D) zigzag chain structure. Each Co ion is symmetrically coordinated by four pyridine ligands and also coordinates with two NCS− anions. Compound 1 was characterized by elemental analyses, IR spectra and UV-visible spectra. The third-order non-linear optical (NLO) properties were also investigated and they exhibit non-linear absorption and self-defocusing performance with modulus of the hyperpolarizability 9.46 × 10−30 esu for 1 in a 3.6 × 10−4 mol dm−3 DMF solution.