Mineral-Inspired Crystal Growth and Physical Properties of Na2Cu(SO4)2 and Review of Na2M(SO4)2(H2O)x (x = 0–6) Compounds

• DOI: 10.1021/acs.cgd.8b01658
• Publication Date: 2018-12-19T00:45:28Z
• Authors: Vadim M. Kovrugin; Diana O. Nekrasova; Oleg I. Siidra; Olivier Mentré; Christian Masquelier; Sergey Yu. Stefan...; Marie Colmont
• Keywords: [CHIM.INOR] Chemical Sciences/Inorganic chemistry; [CHIM.CRIS]Chemical Sciences/Cristallography; 500; [CHIM.CRIS] Chemical Sciences/Cristallography; [CHIM.INOR]Chemical Sciences/Inorganic chemistry; 540; 01 natural sciences; 0104 chemical sciences

Single crystals and polycrystalline samples of a synthetic analogue of saranchinaite, Na2Cu(SO4)2, have been prepared by two different methods. The structural analysis revealed unusual heptahedral CuO7 coordination [4 + 1 + 2] of Cu2+ cations in its crystal structure. The title compound crystallizes in the noncentrosymmetric space group P21 and exhibits the averaged nonlinear coefficient ⟨d⟩ = 1.4[d14(SiO2)] ≈ 0.5 pm/V. Electrochemical tests showed a limited electrochemical performance and low mobility of Na ions in the structure. The magnetic properties of Na2Cu(SO4)2 reflect its crystal structure with half of copper cations as mainly paramagnetic and the other half as strongly engaged in antiferromagnetic dimer interactions. Analysis of the synthesis methods for preparation of the other Na-containing anhydrous sulfates is reported. Dehydration of the Na2M(SO4)2(H2O)x (x = 0–6) phases, various structure types, and the structural complexity of Na2M(SO4)2 (M = Mn, Co, Ni, Cu, Zn, Cd) compounds are also dis...