Extended metal-organic solids based on benzenepolycarboxylic and aminobenzoic acids

Journal of Chemical Sciences

D Krishnamurthy¹  G Anantharaman¹  M Sathiyendiran¹  R Murugavel1¹  M G Walawalkar¹ 

[1] Department of Chemistry, Indian Institute of Technology, Powai, Mumbai 400 076, India$$

关键词: Coordination polymer;    aminobenzoic acid;    benzene tetracarboxylic acid;    alkaline earth metals;    supramolecular chemistry.;   

DOI  :  

来源: Indian Academy of Sciences

【 摘 要 】

This article describes the recent results obtained in our laboratory on the interaction of polyfunctional ligands with divalent alkaline earth metal ions and a few divalent transition metal ions. Treatment of MCl2$cdot$ 𝑛H2O (M = Mg, Ca, Sr or Ba) with 2-amino benzoic acid leads to the formation of complexes [Mg(2-aba)2] (1), [Ca(2-aba)2(OH2)3]∞ (2), [{Sr(2-aba)2(OH2)2}2$cdot$H2O)]∞ (3), [Ba(2-aba)2(OH2)]∞ (4), respectively. While the calcium ions in 2 are hepta-coordinated, the strontium and barium ions in 3 and 4 reveal a coordination number of nine apart from additional metal-metal interactions. Apart from the carboxylate functionality, the amino group also binds to the metal centres in the case of strontium and barium complexes 3 and 4. Complexes [{Mg(H2O)6}(4-aba)2$cdot$2H2O] (5), [Ca(4-aba)2(H2O)2] (6) prepared from 4-aminobenzoic acid reveal more open or layered structures. Interaction of 2-mercaptobenzoic acid with MCl2$cdot$6H2O (M = Mg, Ca), however, leads to the.oxidation of the thiol group resulting in the disulphide 2,2'-dithiobis(benzoic acid). New metal-organic framework based hydrogen-bonded porous solids [{M(btec)(OH2)4}𝑛 $cdot$ 𝑛(C4H12N2) 4𝑛H2O] (btec = 1,2,4,5-benzene tetracarboxylate) (M = Co 9; Ni 10; Zn 11) have been synthesized from 1,2,4,5-benzene tetracarboxylic acid in the presence of piperazine. These compounds are made up of extensively hydrogenbonded alternating layers of anionic M-btec co-ordination polymer and piperazinium cations. Compounds 2-11 described herein form polymeric networks in the solid-state with the aid of different coordinating capabilities of the carboxylate anions hydrogen bonding interactions.

【 授权许可】

Unknown