Crystal Structure of New Fluoride Complexes of Indium(III) M[Cu(H2O)4]InF6·nH2O (M = Rb, Cs, NH4; n = 0, 1)

Fluoride complexes of indium(III) with mixed monovalent M+ (M = Rb, Cs, NH4) and divalent [Cu(H2O)4]2+ cations of the composition M[Cu(H2O)4]InF6·nH2O (M = Rb, Cs, NH4; n = 0, 1) are synthesized for the first time and their crystal structures with a polymer chain character are studied. The structures of M[Cu(H2O)4]InF6·nH2O (M = Rb, Cs, NH4; n = 0, 1) are formed of monovalent Rb+, Cs+, NH4+ cations respectively, complex [Cu(H2O)4]2+ cations, slightly distorted octahedral complex [InF6]3– anions, and crystallization H2O molecules. By attaching one F atom from the neighboring InF6 groups, the [Cu(H2O)4]2+ cations form distorted octahedral Cu(H2O)4F2 groups. Via the bridging F atoms, the [Cu(H2O)4]2+ cations and [InF6]3– anions alternatively join into zigzag anionic polymer chains. A branched system of hydrogen O–H···F, O–H···Ow, and N–H···F bonds arrange the anionic chains into a threedimensional framework in whose voids the monovalent cations and crystallization H2O molecules are located. The structures of M[Cu(H2O)4]InF6·nH2O (M = Rb, Cs, NH4; n = 0, 1) are a new structure type.