Thiocyanate mediated structural diversity in phenol based "end-off" compartmental ligand complexes of group 12 metal ions: Studies on their photophysical properties and phosphatase like activity.

The reaction of a pentadentate compartmental ligand LH, namely 4-tert-Butyl-2,6-bis-[(2-pyridin-2-yl-ethylimino)-methyl]-phenol, with group 12 metal ions (Zn, Cd, Hg) followed by addition of NaSCN afforded one discrete dinuclear complex Zn(L)(SCN), and two polymeric 1D species [Cd(L)(SCN)(AcO)] (2) and [Hg(L)(SCN)] (3). All the complexes have been structurally characterized by single crystal X-ray diffraction. The crystal structure of the complexes reveals different coordination modes of thiocyanate anion that affect the different topology detected in the compounds: the anions are μ-NCS and μ-NCS connected in complex 1, while μ-NCS bridging mode is observed in 2, and μ-SCN and μ-NCS in 3. The polymeric Hg complex of the bicompartmental ligand system here reported is unprecedented. Detail study of their photophysical properties including the phosphorescence spectra at 77K has been done. Phosphatase like activity of all the three complexes has been performed in DMSO-HO medium and their activity follows the order of 1>2>>3.