Elaboration and characterization of a new phosphate Mg1.74Cu1.26(PO4)2?H2O with morphotropic structure

The single crystal of Mg1.74Cu1.26(PO4)(2)center dot H2O was synthesized hydrothermally and its crystal structure was characterized through X-ray diffraction data. This new phosphate crystallizes in monoclinic system with P2(1)/n space group. Its structure is discussed as a new member of the morphotropic series: MII3(PO4)(2)center dot nH(2)O Three types of cationic sites and two (PO4)(3)- anions make up its crystal structure. The first and second cationic sites are filled by Cu2+ and Mg2+ respectively, while the last one is occupied by a mixture of the two cations Mg(2+ )and Cu2+.The connecting of the basic building results in a net framework with two kinds of layers extending parallel to (-10 1). The first is built up of [Cu2O8] dimers joined by edge-sharing to PO4 tetrahedra. Common edges connecting [(Cu/Mg)(2)O-8(H2O)(2)] dimers and [MgO6] octahedra form the second layer, which is more corrugated. Adjacent layers are linked by PO4 groups, revealing channels running parallel to the [1 0 1] direction and contain H atoms from coordinated H2O. Across these channels, water molecules connect with framework oxygen atoms through O---H---O hydrogen bonding interactions. Copyright (c) 2022 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 3rd International Congress on Materials & Structural Stability.