Abstract: | The Crystal Structures of (NH4)2ReCl6], ReCl2(CH3CN)4]2ReCl6] · 2CH3CN and ReCl4(18)(Crown-6)] Brown single crystals of (NH4)2ReCl6] are formed by the reaction of NH4Cl with ReCl5 in a suspension of diethylether. ReCl2(CH3CN)4]2ReCl6] · 2CH3CN crystallizes as brown crystal plates from a solution of ReCl5 in acetonitrile. Lustrous green single crystals of ReCl4(18-crown-6)] are obtained by the reaction of 18-crown-6 with ReCl5 in a dichloromethane suspension. All rhenium compounds are characterized by IR spectroscopy and by crystal structure determinations. (NH4)2ReCl6]: Space group Fm3 m, Z = 4, 75 observed unique reflections, R = 0.01. Lattice constant at ?70°C: a = 989.0(1) pm. The compound crystallizes in the (NH4)2PtCl6] type, the Re? Cl distance is 235.5(1) pm. ReCl2(CH3CN)4]2ReCl6] · 2CH3CN: Space group P1, Z = 1, 2459 observed unique reflections, R = 0.12. Lattice dimensions at ?60°C: a = 859.0(1), b = 974.2(7), c = 1287.3(7) pm, α = 102.69(5)°, b? = 105.24(7)°, γ = 102.25(8)°. The structure consists of two symmetry-independent ReCl2(CH3CN)4]+ ions with trans chlorine atoms, ReCl6]2? ions, and included acetonitrile molecules. In the cations the Re? Cl bond lengths are 233 pm in average, in the anion they are 235 pm in average. ReCl4(18-crown-6)]: Space group P21/n, Z = 4, 3 633 observed unique reflections, R = 0.06. Lattice dimensions at ?70°C: a = 1040.2(4), b = 1794.7(5), c = 1090.0(5) pm, b? = 108.91(4)°. The compound forms a molecular structure, in which the rhenium atom is octahedrally coordinated by the four chlorine atoms and by two oxygen atoms of the crown ether molecule. |