Cyanate cadmium(II) coordination compounds with 2,3,5,6-tetrakis(2-pyridyl)pyrazine – Synthesis, structure and luminescent properties

Two cadmium(II) coordination compounds [Cd(NCO) 2 (tppz)] ( 1 ) and [Cd 2 (μ 1,1 -NCO) 2 (μ 1,3 -NCO) 2 (μ-tppz)] n ( 2 ) have been successfully synthesized in the reaction of CdCl 2 or Cd(NO 3 ) 2 with a versatile polydentate ligand (2,3,5,6-tetrakis(2-pyridyl)pyrazine - tppz ) and pseudohalide NCO – ions. The resulted compounds were structurally characterized by single crystal X-ray diffraction analysis and further characterized by infrared spectra, powder X-ray diffraction and thermal analysis. The photoluminescence behaviour was investigated in solid state for 1 and 2 and then compared to the free organic ligand. The luminescent properties of tppz were investigated for two polymorphs (monoclinic P2 1 / n and tetragonal I4 1 / a ). Moreover, the Hirshfeld surface analysis has been used to determine the effect of intermolecular interactions on emission properties of these polymorphs. In addition, the luminescent properties of mononuclear coordination compound were examined in acetonitrile solution.