ABSTRACT
We report the crystal structures of two tin(IV) sulfate polymorphs Sn(SO4)2-I (P21/c (no. 14), a = 504.34(3), b = 1065.43(6), c = 1065.47(6) pm, ß = 91.991(2)°, 4617 independent reflections, 104 refined parameters, wR2 = 0.096) and Sn(SO4)2-II (P21/n (no. 14), a = 753.90(3), b = 802.39(3), c = 914.47(3) pm, ß = 92.496(2)°, 3970 independent reflections, 101 refined parameters, wR2 = 0.033). Moreover, the first heterovalent tin sulfate Sn2(SO4)3 is reported which adopts space group P1Ì (no. 2) (a = 483.78(9), b = 809.9(2), c = 1210.7(2) pm, α = 89.007(7)°, ß = 86.381(7)°, γ = 73.344(7)°, 1602 independent reflections, 152 refined parameters, wR2 = 0.059). Finally, SnSO4 - the only tin sulfate with known crystal structure - was revised and information complemented. The optical and thermal properties of all tin sulfates are investigated by FTIR, UV-vis, luminescence and 119Sn Mössbauer spectroscopy as well as thermogravimetry and compared.
ABSTRACT
The reaction of Mo(II)acetate, concentrated triflic acid and the alkaline metal triflates A(CF(3)SO(3)) (A = Na, Rb, Cs) in sealed glass ampoules at 110 °C yielded red single crystals of A[Mo(2)(CF(3)SO(3))(5)]·2CF(3)SO(3)H (A = Na: triclinic, P-1, Z = 4, a = 13.714(1) Å, b = 14.339(1) Å, c = 21.340(2) Å, α = 81.78(1)°, ß = 75.21(1)°, γ = 62.65(1)°; A = Rb/Cs: monoclinic, P2(1)/m, Z = 2, a = 11.561(1)/11.584(1) Å, b = 14.817(1)/14.9472(8) Å, c = 11.6208(1)/11.744(1) Å, ß = 112.38(1)/113.48(1)°). The crystal structures contain dumbbell shaped [Mo(2)] moieties surrounded by three chelating and four monodentate triflate anions leading to an opening of the typical paddlewheel fragment at one of its edges. The monodentate triflate anions are connected to further [Mo(2)] dumbbells leading to infinite anionic chains according to (∞)(1)[Mo(2)(CF(3)SO(3))(3/1)(CF(3)SO(3))(4/2)](-). The charge balance is achieved by the alkaline metal ions that are additionally coordinated by triflic acid molecules. Theoretical investigations were preformed on the open paddlewheel fragment and are in good agreement with the experimental findings. According to DTA/TG measurements and the XRD investigations the decomposition of the compounds occurs in multiple steps and leads to MoO(2) and A(2)MoO(4).
ABSTRACT
Oxide methanesulfonates of Mo, U, Re, and V have been prepared by reaction of MoO(3), UO(2)(CH(3)COO)(2)·2H(2)O, Re(2)O(7)(H(2)O)(2), and V(2)O(5) with CH(3)SO(3)H or mixtures thereof with its anhydride. These compounds are the first examples of solvent-free oxide methanesulfonates of these elements. MoO(2)(CH(3)SO(3))(2) (Pbca, a=1487.05(4), b=752.55(2), c=1549.61(5) pm, V=1.73414(9) nm(3), Z=8) contains [MoO(2)] moieties connected by [CH(3)SO(3)] ions to form layers parallel to (100). UO(2)(CH(3)SO(3))(2) (P2(1)/c, a=1320.4(1), b=1014.41(6), c=1533.7(1) pm, ß=112.80(1)°, V=1.8937(3) nm(3), Z=8) consists of linear UO(2)(2+) ions coordinated by five [CH(3)SO(3)] ions, forming a layer structure. VO(CH(3)SO(3))(2) (P2(1)/c, a=1136.5(1), b=869.87(7), c=915.5(1) pm, ß=113.66(1)°, V=0.8290(2) nm(3), Z=4) contains [VO] units connected by methanesulfonate anions to form corrugated layers parallel to (100). In ReO(3)(CH(3)SO(3)) (P1, a=574.0(1), b=1279.6(3), c=1641.9(3) pm, α=102.08(2), ß=96.11(2), γ=99.04(2)°, V=1.1523(4) nm(3), Z=8) a chain structure exhibiting infinite O-[ReO(2)]-O-[ReO(2)]-O chains is formed. Each [ReO(2)]-O-[ReO(2)] unit is coordinated by two bidentate [CH(3)SO(3)] ions. V(2)O(3)(CH(3)SO(3))(4) (I2/a, a=1645.2(3), b=583.1(1), c=1670.2(3) pm, ß=102.58(3), V=1.5637(5) pm(3), Z=4) adopts a chain structure, too, but contains discrete [VO]-O-[VO] moieties, each coordinated by two bidentate [CH(3)SO(3)] ligands. Additional methanesulfonate ions connect the [V(2)O(3)] groups along [001]. Thermal decomposition of the compounds was monitored under N(2) and O(2) atmosphere by thermogravimetric/differential thermal analysis and XRD measurements. Under N(2) the decomposition proceeds with reduction of the metal leading to the oxides MoO(2), U(3)O(7), V(4)O(7), and VO(2); for MoO(2)(CH(3)SO(3))(2), a small amount of MoS(2) is formed. If the thermal decomposition is carried out in a atmosphere of O(2) the oxides MoO(3) and V(2)O(5) are formed.
