From Dicarboxylic Acid to Tetranuclear Metallamacrocyclic Complex and 1D and 2D Polymers

Abstract

A series of metal carboxylate complexes have been synthesized by treating 2,6-dicarboxamido-(2-pyridyl)-pyridine (H2dcapp), pyridine-2,5-dicarboxylate acid (2,5-H2pda), and phenanthroline (phen) with metal salts under hydrothermal conditions. Carboxylate groups as building blocks are used to link adjacent metal centers forming a one-dimensional (1D) coordination polymeric chain [Mn2(2,6-pda)2(H2O)3]∞ (1) (2,6-pda = pyridine-2,6-dicarboxylate), a two-dimensional (2D) sheet network [Pb(2,6-pda)]∞ (2), a 2D hybrid rhombic grid coordination polymer [Cd(phen)(2,5-pda)]∞ (3), a 1D hybrid zigzag chain {[Zn(phen)(2,5-pda)]·H2O}∞ (4), and a tetranuclear metallamacrocyclic complex {[Zn(2,5-pda)(H2O)2][Zn(2,5-pda)(H2O)3]}2 (5). Their thermal properties were studied through TG−DT analyses. The magnetic measurement of polymer 1 reveals that typical antiferromagnetic exchange exists between Mn centers with J = −0.215 cm-1.