title: Stabilization of acyclic water tetramer in a copper(II) malonate framework structure.
abstract: Copper(II) complex [Cu(dpq)(mal)(H(2)O)]·3H(2)O (1) (dpq = dipyrido-[3,2-d:2',3'-f]-quinoxaline, mal = malonato) was synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis and single-crystal X-ray crystallography. The single-crystal X-ray structure of 1 reveals a square pyramidal structure, with the dipyrido-[3,2-d:2',3'-f]-quinoxaline and malonato at the equatorial positions and a water molecule at the axial position. The molecule acts as a building block generating a supramolecular three-dimensional metal-organic framework (MOF) encapsulating metal linked acyclic water tetramer. The H-bonding capacity of malonato and the π-π stacking interactions of dipyrido-[3,2-d:2',3'-f]-quinoxaline further reinforce the framework. The copper(II) bound hydroxyl group is demonstrated to mediate hydrolytic cleavage of plasmid pBR322 DNA under dark conditions.
authors.affiliation: Department of Chemistry, University of Pune, Pune, 411 007, India.
authors.forename: Megha S
authors.initials: MS
authors.lastname: Deshpande
authors.forename: Avinash S
authors.initials: AS
authors.lastname: Kumbhar
authors.forename: Christian
authors.initials: C
authors.lastname: Näther