Crystal structure of tetraethylammonium hexachloridotantalate(V), C₈H₂₀Cl₆NTa

Abstract

C 8 H 20 Cl 6 N1Ta1, monoclinic, P21/n (no. 14), a = 7.1550(4) Å, b = 10.0090(6) Å, c = 11.6290(4) Å, β = 98.487(5)°, CCDC no.: 1441007The crystal structure is shown in the gure, Tables 1-3 contain details of the measurement method and a list of the atoms including atomic coordinates and displacement parameters. Source of materialTetraethylammonium hexachloridotantalate(V) was prepared by modifying the known literature synthesis of bis(tetraethylammonium)aqua tetrachlorido-oxidoniobate(V) [1, 2]. TaCl5 (0.50 g, 1.85 mmol) and tetraethylammonium chloride monohydrate (0.257 g, 1.85 mmol) were dissolved in acetonitrile. The faintly yellow solution was re uxed for ten hours while fumes of hydrogen chloride were relieved and the colour of the solution disappeared. After vacuum evaporation of excess solvent, colourless crystals

Preparation, Crystal Structure, and Luminescence Properties of Zeolite LTA Containing Extraframework Tantalum(V), Tantalum(II), Thallium(I), and Chloride

“…The difference, 0.40 Å, between the Ta2–Cl1 distance, 2.89(5) Å, and the sum of the Ta 5+ and Cl – ionic radii, 0.68 + 1.81 = 2.49 Å, is therefore too large to be explained by decreasing the oxidation state at Ta2 from 5+ to a lower value. Shannon estimates that the difference in octahedral radius between Ta 5+ and Ta 3+ is 0.08 Å .…”

“…The Ta 5+ –Cl – bond lengths in various compounds of TaCl 6 – lie in a narrow range, 2.317(3)–2.362(3) Å. They range from 2.344(1) to 2.354(1) Å in tetraethylammonium hexachlorotantalate­(V), from 2.342 to 2.344 Å in [Na­(NCCH 3 ) 6 ]­[TaCl 6 ], from 2.317(3) to 2.362(3) Å in [C 3 H 5 N 2 ]­[TaCl 6 ] (imidazolium hexachlorotantalate­(V)), from 2.303(5) to 2.345(4) Å in [Ta­(tmhd) 4 ]­[TaCl 6 ], and from 2.3344(10) to 2.3586(11) Å in [(MePhCO) 2 H]­[TaCl 6 ] . These distances are all much shorter than the 2.89(5) Å distance seen in this structure.…”

“…In support of this tentative conclusion are the colors of hexachlorotantalate(V) and hexachlorotantalate(IV) in their compounds with colorless cations. The former are both colorless, 57,58 while the latter are both black. 62,63 Because the crystal studied here was colorless, we conclude that the tantalum ions at Ta2 are in the 5+ oxidation state, unmodified from the TaCl 5 (g) reagent used.…”

“…The Ta2−Cl1 bond length, 2.89(5) Å, is substantially longer than any of the following sums of radii: Ta 5+ −Cl − = 0.64 52,54 (0.68) 56 + 1.81 = 2.45 (2.49) Å, Ta 4+ −Cl − = 0.68 + 1.81 = 2.49 Å, and Ta 3+ −Cl − = 0.72 + 1.81 = 2.53 Å. 52,54,56 Lower oxidation states for Ta are not considered because octahedral hexachlorotantalum has been reported only for Ta(V) and Ta(IV); 55 The difference, 0.40 Å, between the Ta2−Cl1 distance, 2.89(5) Å, and the sum of the Ta 5+ and Cl − ionic radii, 0.68 + 1.81 = 2.49 Å, 57 is therefore too large to be explained by decreasing the oxidation state at Ta2 from 5+ to a lower value. Shannon estimates that the difference in octahedral radius between Ta 5+ and Ta 3+ is 0.08 Å.…”