Crystal Structure and Solid-State Reactivity of a Cd(II) Polymeric Complex with Acetylenedicarboxylic Acid

The novel one-dimensional coordination polymer [Cd(ADC)(H₂O)₃] H₂O, where ADC^2- =\nacetylenedicarboxylate dianion, was synthesized and characterized by single-crystal X-ray\ndiffraction. The titled compound crystallizes in the monoclinic system, P2₁/n, a = 6.908(1)\nÅ, b = 7.946(1) Å, c = 16.390(1) Å, β = 100.21(1)°, V = 885.4(2) ų, and Z = 4. The structure\nis made up of metal−organic chains linked by hydrogen bonds to form channels along the\nb axis. The carbon−carbon triple bonds are in close proximity (3.27 Å) along the a axis. This\ninduces, upon heating, polymerization with formation of conjugated polycarboxylic chains.\nDetailed EPR studies have been performed in order to understand the polymerization process.