Dinuclear Copper(II) Phosphonates Containing Chelating Nitrogen Ligands: Synthesis, Structure, Magnetism and Nuclease Activity

✍ Scribed by Vadapalli Chandrasekhar; Tapas Senapati; Rodolphe Clérac

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 421 KB
• Volume: 2009
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/ejic.200900035

✦ Synopsis

Abstract

The reaction of Cu(ClO~4~)~2~·6H~2~O with RPO~3~H~2~ (R = cyclopentyl, isopropyl, trichloromethyl) in the presence of chelating nitrogen ligands bpya or bpy afforded dinuclear copper phosphonates [Cu~2~(μ~2~‐C~5~H~9~PO~3~)~2~(bpya)~2~(H~2~O)~2~] (H~2~O)~4~ (1), [Cu~2~(μ~2~‐C~3~H~7~PO~3~)~2~(bpya)~2~(H~2~O)~2~] (H~2~O)~2~ (2) and [Cu~2~(μ~2~‐CCl~3~PO~3~)~2~(bpy)~2~(MeOH)~2~] (H~2~O) (3) [bpya = 2,2′‐bipyridylamine, bpy = 2,2′‐bipyridine]. The molecular structures of these complexes reveal that they are isostructural and possess two copper centres that are bridged to each other by two isobidentate phosphonate ligands generating an eight‐membered Cu~2~O~4~P~2~ ring. Magnetic studies on 2 reveal antiferromagnetic behaviour at low temperatures. Dinuclear complexes 1–3 were found to be excellent nucleases and can convert supercoiled pBR322 DNA form I into nick form II in only 30 min without the need for any external oxidant through a hydrolytic pathway. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)