Novel Cyano-Bridged 4f-3d Coordination Polymers with a Unique 2D Topological Architecture and Unusual Magnetic Behavior

Abstract

Cyano-bridged bimetallic hybrid Prussian Blue one- to three-dimensional (1D-3D) coordination polymers based on [M(CN)6]3- (M = Fe, Cr, Mn) have attracted great attention because of their rich and interesting structures and magnetic behaviors. The previous study implies that increasing dimensionality may enhance and improve bulk magnetic properties.Our strategy for the rational synthesis of high-dimensional network is to use a suitable combination of cyanide groups and other bridging ligands. Here, 2,2'-bipyrimidine (bpym) was selected, in preference to 4,4'-bipyrazine and pyrazine, because it is more capable of transmitting magnetic interactions and its bis(chelating) coordination modes facilitate connection between lanthanide ions. Unexpectedly, two novel coordination polymers [NdM(bpym)(H2O)4(CN)6]3H2O (M = Fe 1, Co 2;) were obtained, which have a unique 2D topological architecture, and exhibit unusual magnetic behavior.