M2(pbtcH)(phen)2(H2O)2 [M(II)=Co, Ni]: Mixed-ligated metal phosphonates based on 5-phosphonatophenyl-1,2,4-tricarboxylic acid showing double chain structures

Abstract

Two new mixed-ligated metal phosphonates, M2(pbtcH)(phen)2(H2O)2 [M(II) = Co (1), Ni (2)] (pbtcH5 = 5-phosphonatophenyl-1,2,4-tricarboxylic acid, phen = 1,10-phenanthroline), have been synthesized and characterized. Both show one-dimensional double chain structures, where the M(phen)(H2O) moieties are chelated and bridged by pbtcH4− through the carboxylate and phosphonate oxygen atoms. The chains are connected by hydrogen bonding interactions and π–π stacking, forming a three-dimensional supramolecular structure. The IR and magnetic properties of the two compounds are also investigated.