Crystal Structure And Magnetic Properties Of An One-Dimension Heptacoordinated Manganese Helical Chain Polymer Using Fumaratoligand As Bridging SpacerAuthor(s): Li-Hui Jia, Zu- Li Liu, Wei Liu, Ai-Qing Zhao, Kai-Lun Yao
An infinite helica clhain coordination polymer [Mn2(fumarate)(bipy)2 (H2O)2]m (1) (bipy=2,2Â-bipyridine) have been prepared and characterized by means of X-ray analysis and magnetic measurements. The heptacoordinated manganese(ïï) ion displays a distorted pentagonal bipyramid configuration by virtue of two nitrogen atoms from 2,2Â- bipyrinde, four oxygen atoms from two different fumarate ligands, and one oxygen atom of a coordinated water molecule. Each manganese centers are bridged by bis-bidentate fumarate ligands.to yield infinite helical chains structure along b axis . The magnetic data for 1 has been analysed and interpreted in terms of Heisenberg chain model corrected by a mean molecular field . The fitting parameters obtained for J, g and zJÂ are -0.57, 1.99, and -0.08, respectively, indicating the existence of weak antiferromagnetic intrachain and interchain interactions. The longdistance magnetic interactions through bridging fumaratoligands is discussed.