KCu(SeO 4 )Cl(H 2 O) 2 , a first copper chloride selenate
Résumé
Abstract A first copper chloride selenate was obtained upon attempted preparation of a selenate analog of chlorothionite. The new compound is monoclinic, P 2 1 / c , a = 7.1833(5) Å, b = 11.7784(8) Å, c = 8.2419(6) Å, β = 91.083(2)°, V = 697.20(8) Å 3 , R 1 = 0.033. KCu(SeO 4 )Cl(H 2 O) 2 has no structural analogs and adds to the small family of transition metal selenate halides. The CuO 3 (H 2 O) 2 Cl strongly distorted octahedra share common O–O edges thus forming dimeric units with a Cu–Cu distance of 3.49 Å. Dimeric units and SeO 4 tetrahedra in KCu(SeO 4 )Cl(H 2 O) 2 share common O atoms to produce unique [Cu(SeO 4 )Cl(H 2 O) 2 ] − chains. We discuss further perspectives of the selenate halide family and expected differences in crystal chemistry of sulfate and selenate halides.