title: Layered copper compounds based on 4-(3-bromothienyl)phosphonate (BTP): weak ferromagnetism observed in [Cu2(4,4'-bpy)0.5(BTP)2].H2O.
abstract: Two copper phosphonates based on 4-(3-bromothienyl)phosphonic acid (BTPH2) with formula Cu(H2O)(BTP) (1) and [Cu2(4,4'-bpy)0.5(BTP)2].H2O (2) are reported. Compound 1 has a layered structure in which dimers of {Cu2O2}, made up of edge-sharing {CuO6} octahedra, are bridged by both the {PO3C} tetrahedra through corner-sharing and the water molecules. Compound 2 exhibits a novel layered structure where the {Cu2(BTP)2} columns, containing {Cu4O6} tetrameric cores and O-P-O linkages, are connected by 4,4'-bipyridine. In both cases, the 3-bromothienyl groups are grafted on the two sides of the layers. Magnetic studies reveal that antiferromagnetic interactions are mediated between the Cu(II) centers in 1, while for 2, weak ferromagnetism resulted from spin canting is observed. Electrochemical properties of compounds 1-2 are also investigated.
authors.affiliation: State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, P. R. China.
authors.forename: Li-Rong
authors.initials: LR
authors.lastname: Guo
authors.forename: Feng
authors.initials: F
authors.lastname: Zhu
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.forename: Yi-Zhi
authors.initials: YZ
authors.lastname: Li
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Zheng