The Coordination Polymer Cr(en)₂As₂VO₇ Consisting of Alternating VO₄ Tetrahedra and As₂O₅ Handles Decorated by Cr³⁺ Centered Complexes

Abstract

The new coordination polymer Cr(en)2As2VO7 (en=ethylenediamine) was synthesized under solvothermal conditions as deep red crystals. In the crystal structure VO4 tetrahedra and As2O5 handles formed by corner‐sharing of two AsO3 pyramidal units are joined by common oxygen atoms into an undulated chain that is directed along the crystallographic b‐axis. The chain is decorated by [Cr(en)2]3+ complexes with the Cr3+ cation having bonds to two terminal O2− anions of the As2O5 moiety thus generating a CrN4O2 octahedron, which displays a cis‐configuration. The connection mode between Cr3+ and As2O5 leads to formation of a six‐membered CrAs2O3 ring. The chains are arranged in a layer‐like fashion in the (001) plane and these layers are stacked along [001]. A large number of N−H⋅⋅⋅O and C−H⋅⋅⋅O hydrogen bonds generate a three dimensional network. A Hirshfeld surface analysis was performed for visualizing the extended interchain interactions. The hydrogen bonding interactions are clearly detected in the IR spectrum. The UV‐Vis spectrum shows an absorption at 2.3 eV which is in agreement with the red color of the sample.