Syntheses, Crystal Structure, and Nuclease Activity of Oxalato-Bridged Dicopper(II) Complexes with Planar N-Donor Heterocyclic Bases
✍ Scribed by Anitha M. Thomas; Girish Neelakanta; Subramony Mahadevan; Munirathinam Nethaji; Akhil R. Chakravarty
- Publisher
- John Wiley and Sons
- Year
- 2002
- Tongue
- English
- Weight
- 150 KB
- Volume
- 2002
- Category
- Article
- ISSN
- 1434-1948
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✦ Synopsis
Oxalato-bridged dicopper(II) complexes [{CuL(H 2 O)} 2 (µ-ox)]-(ClO 4 ) 2 (1-4), where L is a bidentate chelating heterocyclic base such as 2,2Ј-bipyridine (bpy, 1), 1,10-phenanthroline (phen, 2), dipyridoquinoxaline (dpq, 3) and dipyridophenazine (dppz, 4), were prepared by treatment of copper(II) perchlorate hexahydrate with sodium oxalate and L in aqueous ethanol. Complex 3 has been structurally characterised. The coordination geometry of the copper centres is essentially square-pyramidal. The {CuL(H 2 O)} units are bridged by an oxalate moiety to form the discrete dimeric core. Magnetic studies in the 20-300 K temperature range show the presence of an antiferromagnetically coupled dicopper(II) unit, giving -2J values in the 346-384 cm -1 range. The redox-active complexes retain the dimeric core in solution, and two quasireversible Cu II /Cu I couples are observed in the poten- [a