Heterobimetallic Tungsten/Molybdenum(IV)−Copper(II) MOFs Constructed by a Unique 2D → 3D Architecture and Exhibiting New Topology and Magnetic Properties

The present study describes the designed synthesis, X-ray structures, and magnetic properties of two 3D cyano-bridged heterobimetallic tungsten/molybdenum(IV)−copper(II) MOFs, {[μ4-M(CN)8]Cu2(DPP)4}n (M = W 1, Mo 2; DPP = 1,3-Di(4-pyridyl)propane). Both MOFs 1 and 2 were constructed by interdiffusion approach in two steps: the first reaction of CuSCN and NH4SCN with the flexible bridging ligand DPP in polar solvent for building a 2D homometallic Cu polymer, and the thereafter conformation of 3D heterobimetallic MOF architectures with [M(CN)8]3− and 2D coordination networks. MOFs 1 and 2 are isomorphous and both crystallize in the tetragonal system and have space group I41/a, with unit cell constants a = 19.734(3) Å, b = 19.734(3) Å, c = 13.989(2) Å for 1, and a = 19.7429(19) Å, b = 19.7429(19) Å, c = 13.9883(15) Å for 2. Our study demonstrates that such heterobimetallic MOFs possess a unique 2D → 3D architecture and exhibit a new 2-nodal topological structure. The magnetic measurement of MOFs shows typical paramagnetic properties and weak ferromagnetic interactions.