External-template-assisted formation of octacyanometalate-based M^V-Mn^II (M = W, Mo) bimetallic coordination polymers with magnetic properties

Three manganese-molybdenum/tungsten bimetallic coordination polymers, two 2D {{[μ₄-M(CN)₈]₂[Mn(dmf)₃]₂[Mn(dmf)₄]}·2DMF}_n (M = W 1, Mo 2) and a 1D {{[μ₄-Mo(CN)₈][Mn(dmf)₄]₂}·(ClO₄)}_n (3), were constructed from the reaction of the (Bu₃NH)₃[M(CN)₈] (M = W, Mo) and Mn(ClO₄)₂·6H₂O molecular building blocks in DMF solvent in the presence (for 1 and 2) or absence (for 3) of the organic ligand bis(benzimidazol-2-yl)pyridine. Single-crystal X-ray diffraction structure analysis indicated that compounds 1 and 2 both crystallize in the monoclinic crystal system with the P2₁/c space group and possess the same 2D network. The 2D layer structures of 1 and 2 have a (3,4)-connected 2-nodal topology with the point symbol {4²·6³·8}{4²·6}. Compound 3 crystallizes in the tetragonal crystal system with the P4₂/m space group. All three compounds are further assembled into 3D supramolecular structures through intermolecular C-H···N or C-H···O hydrogen bonds. The magnetic susceptibility of compounds 1 and 3 was investigated in the temperature range of 2-300 K; these compounds exhibit typical ferrimagnetic properties. 2D coordination polymers {{[μ₄-M(CN)₈]₂[Mn(dmf)₃]₂[Mn(dmf)₄]}·2DMF}_n (M = W, Mo) and a 1D chain compound {{[μ₄-Mo(CN)₈][Mn(dmf)₄]₂}·(ClO₄)}_n are constructed by external-template-assisted formation in the presence and absence of bis(benzimidazol-2-yl)pyridine. All three compounds can be assembled into 3D supramolecular structures, and two of the compounds exhibit typical ferrimagnetic properties.