Synthesis, Crystal Structures And Properties Of CdNi Bimetallic Coordination Polymers

Hofmann-type compounds are chosen as the subject of the dissertation, and eleven coordination polymers with novel structure were constructed by Cd(II) ions, [Ni(CN)4]2- and pyrazine(pz) and its derivatives, 4,4′-bipyridine(bipy), 4,4′-trimethylenedipyridine(tdp). The compounds were characterized by elemental analyses, XRD, IR, TG and their sorption behaviors and photoluminescent properties have been studied. The effects of molecular aspect ratio and substituent groups of ligands on coordination polymer's structures and properties were discussed.1. Three coordination polymers with 3D framework structure were successfully constructed by the pz, bipy, tdp. In the structure of Cd-pz/bipy-Ni, Cd(II) ions and Ni(II) ions were connected by CN alternately to form 2D layer structure, pz and bipy act as bridge ligand linking the 2D sheets [CdNi(CN)4]∞to form 3D framework structure; for Cd-tdp-Ni, the flexible ligand tdp span in neighboring Cd(II) ions to form the 3D network structure which is different from that of Cd-pz/bipy-Ni. The analysis of sorption behavior shows that three compounds can reversibly ab- and desorpt N2.2. Six coordination polymers with 3D/2D structure were successfully constructed by pyrazine derivatives . In 3D framework structure of Cd-2Mpz/2Acpz-Ni, 2-Mpz acts as a bridge ligand linking the adjacent layers of Cd(II), Ni(II) by two N atoms in pyrazine ring, but 2-Acpz acts as a bridge ligand linking two different coordination pattern Cd(II) ions by one N atom in pyrazine ring and one O atom in carboxyl. In 2D structure of other compounds, 2Epz/2Clpz/2SHpz act as terminal ligands coordinating to Cd(II) by one N atom in pyrazine ring, and meanwhile water molecules coordinating to Cd(II) ions. 2-MOpz/2-EOpz act as terminal ligands to coordinate to Cd(II) ions up and down by two N atoms in two pyrazine; CH3COpz coordinate to Cd(II) ions by N atom in pyrazine ring and O atom in substituent group The analysis of sorption behavior show that Cd-2Acpz-Ni reversibly ab- and desorpt N2.