- Synthesis and structure of rhenium(IV) chloride complexes with acetonitrile
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Cis and trans isomers of the tetrachlorodiacetonitrile rhenium(IV) complex were synthesized and isolated. The structure of cis-ReCl4(N≡C- CH3)2 was studied by X-ray crystallography. It was shown that the coordination polyhedron of the central Re(IV) atom is formed by the four chlorine atoms and the nitrogen atoms of two coordinated acetonitrile molecules. The vibrational (IR and Raman) spectra of the cis isomer of the complex in solid state were interpreted by factor-group analysis. A comparison of the IR spectra of two isomers confirmed that they are cis and trans isomers. Nauka/Interperiodica 2007.
- Volkov,Mykhalichko,Pekhn'o,Yanko,Aleksandrova,Khar'kova,Arsenin
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- Structure relationships between tetraselenium(2+) hexachlorometalates: Synthesis and crystal structure of Se4[ReCl6] and the solid state phase transition of Se4[MCl6](M = Zr, Hf)
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The reaction of Se, SECl4, and ReCl4 in a closed, evacuated glass ampoule at 485 K yields dark-red moisture sensitive crystals of Se4[ReCl6] (orthorhombic, Pccn, a = 1091.5(1), b = 1057.2(1), c = 1015.0(1)pm). The crystal structure consists of almost square-planar Se42+ cations and slightly distorted octahedral [ReCl6]2- anions. Se4[ReCl6] is paramagnetic with a moment of 3.54 μB/Re according to a d3 configuration and Re(IV). The magnetic moment obeys the Curie-Weiss law with a Weiss constant of -33 K. The already known compounds Se4[ZrCl6] and Se4[HfCl6] crystallize in a closely related structure with tetragonal symmetry (space group P42/ncm). Both undergo a phase transition in the solid state into an orthorhombic low temperature form, which is isotypic to Se4[ReCl6]. The phase transition was monitored by single crystal and powder diffraction, the transition temperature was determined to 193(1) K for Se4[ZrCl6]. The changes of the lattice constants with temperature imply a displacive transition of mainly second order which is allowed by the translationsgleiche supergroup-subgroup relation of index 2 between the space groups. No phase transition into a tetragonal high-temperature form could be observed for the orthorhombic Se4[ReCl6].
- Beck, Johannes,Desgroseilliers, Antje,Mller-Buschbaum, Klaus,Schlitt, Klaus-Jrgen
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p. 1145 - 1151
(2008/10/08)
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- Synthesis and crystal structure of (PCl4)[Re2Cl9]
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The reaction between PCl3 and ReCl5 yielded at 200 °C the ionic tetrachlorophosphonium dirhenium nonachloride, (PCl4)[Re2Cl9]. Single crystal X-ray diffraction analysis revealed a monoclinic unit cell: a = 8.616(3) A?, b = 10.449(4) A?, c = 9.397(3) A?, β= 99.72(3)°, V = 833.9(5) A?3, Z = 2, sp. gr. P21/m, wR2 = 0.1083 and R1 = 0.0527. The ionic compound is built from tetrahedra PCl4+ and face-sharing bioctahedra Re2Cl9-. The Re-Re distance, 2.724 A?, indicates the presence of direct Re-Re interaction.
- Baranov,Khvorykh,Troyanov
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p. 1240 - 1242
(2008/10/08)
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- On tetrachlorophosphonium chlorometallates of rhenium and molybdenum: Syntheses, crystal structures, and magnetism of [PCl4]2[Re2Cl10] and [PCl4]3[ReCl6]2, and the magnetic properties of [PCl4]2[Mo2Cl10]
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MoCl4, ReCl4, and ReCl5 react with PCl5 in sealed glass ampoules at temperatures between 220° and 320° to [PCl4]2[Mo2Cl10] (1) [PCl4]2[Re2Cl10] (2), and [PCL4]3[ReCl6]2 (3). 2 crystallizes isotypically to the previously reported 1 and the respective titanium and tin containing analogues. The structure (triclinic, P1 Z = 1, a = 897.3(2), b = 946.0(2), c = 687.13(9) pm, α = 95.59(2)°, β = 95.80(2)°, γ = 101.07(2)°, V = 565.4(2) 106 pm3) is built of tetrahedral [PCl4]+ and edge sharing double octahedral [Re2Cl10]2- ions and can be derived from a hexagonal closest packing of Cl- ions with tetrahedral and octahedral holes partially filled by P(V) and Re(IV), respectively. 3 crystallizes isotypically to [PCL4]3[PCl6][MCl6] (M = Ti, Sn) (tetragonal, P 42/mbc, Z = 4, a = 1496.2(1), c = 1363.2(2) pm). Because no evidence was found for the presence of [PCl6]- ions, Re in 3 has to be of mixed valency with ReIV and ReV sharing the same crystallographic site. The structure can be derived from a cubic closest packing or alternatively from an only sparsely distorted body centered cubic arrangement of Cl- ions which is rarely found for anion arrays. The tetrahedral and octahedral holes are partially filled by PV and MIV/V, respectively. Magnetic measurements show all three compounds to be paramagnetic and confirm the oxidation state IV for Mo and Re in 1 and 2 and the mixed valence (IV/V) for Re in 3.
- Beck,Mueller-Buschbaum,Wolf
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p. 975 - 981
(2008/10/08)
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