title: The magnetic study of a binuclear Cu(ii) complex with pi-pi stacking interactions.
abstract: An anomalous magnetic interaction is observed in a very common and unpublished binuclear copper(ii) complex, [Cu(2)(micro(2)-OOCCH(3))(2)(bpydiol-H)(2)(H(2)O)(2)] (bpydiol-H = mono deprotonated 2,2'-bypyridine-3,3'-diol). In the complex, the two Cu(ii) ions are bridged by two acetate anions and there is a pi-pi stacking interaction between the adjacent pyridine rings. Theoretical calculations reveal that the acetate bridge ligand leads to an antiferromagnetic coupling with 2J = -166.72 cm(-1), whereas the pi-pi stacking developed a ferromagnetic interaction with 2J = 21.0 cm(-1). The offset from the antiferromagnetic interaction and the ferromagnetic interaction may be one of main factors that resulted in the weaker magnetic coupling with experimental fitting 2J = -59.61 cm(-1). This is the first example using theoretical calculations that evaluate the magnetic coupling intensity for a pi-pi stacking system.
authors.affiliation: College of Chemistry, Chemical Engineering and Materials Science, Engineering Research Center of Pesticide and Medicine Intermediate Clean Production, Ministry of Education, Shandong Normal University, Jinan 250014, P. R. China.
authors.forename: Chao
authors.initials: C
authors.lastname: Hou
authors.forename: Jing-Min
authors.initials: JM
authors.lastname: Shi
authors.forename: You-Min
authors.initials: YM
authors.lastname: Sun
authors.forename: Wei
authors.initials: W
authors.lastname: Shi
authors.forename: Peng
authors.initials: P
authors.lastname: Cheng
authors.forename: Lian-Dong
authors.initials: LD
authors.lastname: Liu
mesh_terms: D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008280:Magnetics; D008958:Models, Molecular; D015394:Molecular Structure; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D003300:Copper