Two cadmium–thiocyanate coordination polymers with organic cations: Synthesis, crystal structures and luminescent properties

Two new inorganic–organic hybrid polymers [ClBzQl]2[Cd(SCN)3.5Br0.5]·0.25H2O (1) and [ClBzMePy][Cd(SCN)3] (2) (ClBzQl = 1-(4′-Cl-benzyl)quinolinium cation and ClBzMePy = 1-(4′-Cl-benzyl)-2-methylpyridinium cation) have been synthesized and characterized by IR, UV, elemental analysis and X-ray crystallography. Crystal structure analyses show that two polymers belong to the monoclinic space group P2/n (1) and P21/c (2) with a = 18.548(2) Å, b = 9.526(1) Å, c = 20.689(2) Å, β = 94.008(1)°, V = 3646.6(5) Å3 for 1, and a = 11.195(2) Å, b = 16.415(3) Å, c = 10.751(2) Å, β = 102.930(3)°, V = 1925.7(7) Å3 for 2. The Cd atom exhibits a distorted octahedral coordination geometry for 1 and 2. For 1, a pair of 1,1-μ-SCN− anions and a pair of 1,3-μ-SCN− anions are alternately bridge adjacent Cd centers to form infinite polymeric chains. For 2, adjacent Cd atoms are linked by three 1,3-μ-SCN− anions to form infinite [Cd(SCN)3−]∞ polymeric chains. The luminescent properties of the two polymers in the solid state at room temperature were investigated.