title: A mixed-valence chair-like tetranuclear copper(I,II) cluster with three linking modes of the 3,5-bis(2-pyridyl)-1,2,4-triazole ligand.
abstract: In the tetranuclear copper complex tetrakis[mu-3,5-bis(2-pyridyl)-1,2,4-triazolido]bis[3,5-bis(2-pyridyl)-1,2,4-triazolido]dicopper(I)dicopper(II) dihydrate, [Cu(I)(2)Cu(II)(2)(C(12)H(8)N(5))(6)].2H(2)O, the asymmetric unit is composed of one Cu(I) center, one Cu(II) center, three anionic 3,5-bis(2-pyridyl)-1,2,4-triazole (2-BPT) ligands and one solvent water molecule. The Cu(I) and Cu(II) centers exhibit [Cu(I)N(4)] tetrahedral and [Cu(II)N(6)] octahedral coordination environments, respectively. The three independent 2-BPT ligands adopt different chelating modes, which link the copper centers to generate a chair-like tetranuclear metallomacrocycle with metal-metal distances of about 4.4 x 6.2 A disposed about a crystallographic inversion center. Furthermore, strong pi-pi stacking interactions and O-H...N hydrogen-bonding systems link the tetracopper clusters into a two-dimensional supramolecular network.
authors.affiliation: Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi'an, Shaanxi 710062, People's Republic of China.
authors.forename: Quan Guo
authors.initials: QG
authors.lastname: Zhai
authors.forename: Shu Ni
authors.initials: SN
authors.lastname: Li
authors.forename: Yu Cheng
authors.initials: YC
authors.lastname: Jiang
authors.forename: Man Cheng
authors.initials: MC
authors.lastname: Hu