In situ formed [M(CN)(9)] (M = W, Mo) as a building block for the construction of two nona-cyanometalate-bridged heterometallic coordination polymers

Abstract

Two interesting nona-cyanometalate-based coordination polymers (CPs) {[μ4-M(CN)9Mn2(dpo)2(DMF)4]·DMF}n (M = W 1, Mo 2) were obtained from the reaction of 2,5-di(4-pyridyl)-1,3,4-oxadiazole (dpo) and (Bu3NH)3[M(CN)8] (M = W, Mo) with Mn(NO3)2·6H2O in DMF. It is noteworthy that the in situ generated [M(CN)9]4− (M = W, Mo), the first nona-cyanometalate-based example of precursor, plays the roles of not only the charge-balancing counter anion but also the molecular building blocks in inducing the neutral structures of CPs 1 and 2. Single-crystal diffraction analysis reveals that CPs 1 and 2 crystallize in the tetragonal crystal system with the I4/m space group and possess the same 3D framework structure in a (4,4)-connected mot topology with the point symbol {66}{64·82}2. Variable-temperature magnetic susceptibility measurements in the temperature range of 2 to 300 K reveal that there are antiferromagnetic interactions between the MV (M = W, Mo) of nona-cyanometalate [M(CN)9]4− and MnII spin centers in both CPs 1 and 2.