Efficient Synthetic Strategy to Construct Three-Dimensional 4f−5d Networks Using Neutral Two-Dimensional Layers As Building Blocks

The reaction of neutral two-dimensional (2D) layer Tb(H2O)5W(CN)8 with pyrazine in the acetonitrile solution has led to a 3D bimetallic complex, Tb(H2O)4(pyrazine)0.5W(CN)8 (1). In the structure of 1, the eight-coordinated W center adopts a slightly distorted dodecahedron, while the Tb center exhibits a nine-coordinated slightly distorted tricapped trigonal prism. The Tb3+ atoms and the [W(CN)8]3- units are linked in alternating fashion in the ab crystallographic plane, resulting in an infinite 2D corrugated layers. The linear bis-monodentate pyrazine ligands acting as pillars link adjacent layers along the c axis to form an extended 3D open framework. The possible formation mechanism is proposed, and the temperature has played a crucial role for the formation of 1. Magnetic measurements revealed the presence of ferromagnetic interaction between TbIII and WV centers. 1 marks the first structural pattern using the neutral 2D layer as building block and the first 3D complex with LnIII-[WV(CN)]8 found in octacyanometallate-based system. Such a novel and effective building-block methodology will provide a new attractive path forward in developing functionalities of 3D 4f−5d system and may provide an opportunity to obtain 3D magnet in 4f−5d assembly.