A cesium copper vanadyl-diphosphate: Synthesis, crystal structure and physical properties

• The first copper vanadium-diphosphate Cs2Cu1.1(VO)1.9(P2O7)2 is reported.
• A 3D anionic framework is characterized by disorder in distribution of Cu and V atoms.
• Structural relations with topologically similar compounds are discussed.
• The similarity in behaviour of Cu and V paramagnetic subsystems has been revealed.

A non-centrosymmetric orthorhombic diphosphate, Cs2Cu1+x(VO)2−x(P2O7)2 (x=0.1) with a=13.7364(2) Å, b=9.2666(2) Å, c=11.5678(2) Å, Z=4, has been isolated. Its 3D framework is built from Cu atoms in square pyramidal and square planar coordination, VO5 tetragonal pyramids and P2O7 diphosphate groups, sharing vertices. Large channels are fulfilled by cesium atoms. The ESR study reveals a similarity in behaviour of two paramagnetic (Cu and V) subsystems. The temperature dependences of the ESR linewidth and static magnetic susceptibility data present evidences for a cluster type magnetic ordering in the title compound at T⁎=22 K. The weakness of the relevant anomalies reflects presumably obvious Cu2+ ions and (VO)2+ units disorder in the system. It is supposed that the charge and geometry of the framework are controlled by the Cu2+/(VO)2+ ratio; its variation may lead to a design of new materials.

A microporous 3D anionic framework of the first copper vanadium-diphosphate Cs2Cu1.1(VO)1.9(P2O7)2. The similarity in behaviour of Cu and V paramagnetic subsystems revealed by ESR study.Figure optionsDownload as PowerPoint slide