Synthesis, characterization and magnetic properties of supramolecular metal–organic complexes constructed from flexible–rigid mixed ligands

Two new supramolecular metal–organic complexes have been synthesized under hydrothermal conditions. Complex 1 exhibits a three-dimensional supramolecular network, constructed from [Co 2 (H 3 BPTC) 2 (phen) 2 ] (H 4 BPTC = 3,3′4,4′-benzophenone tetracarboxylate acid, phen = 1,10-phenanthroline) discrete units. Complex 2 similarly exhibits discrete [Cu 2 (DPA) 2 (bipy) 2 (H 2 O) 2 ] (DPA = 1,1′-biphenyl-2,2′-dicarboxylate acid, bipy = 2,2′-bipyridine) units, which are linked to form a three-dimensional supramolecular network through π–π interactions. It is interesting that during the synthesis of complex 1 , the H 4 BPTC ligands undergo partial decomposition to give 1,2,4-benzenetricarboxylate (H 3 BTC) ligands, which react with Co to form [Co 3 (BTC) 2 ] n ( 3 ). Complex 3 shows a three-dimensional covalent network. The magnetic properties of complexes 1 and 2 have been studied.