Crystal structure of bis(trichloro-bis(diethylamido)tantalum(V)), [TaCl3(C4H10N)2]2

C8H20Cl3N2Ta, triclinic, P1 (no. 2), a = 9.1629(6) Å, b = 10.9357(7) Å, c = 14.1722(9) Å, 1 = 83.705(1)°, / = 87.790(1)°, . = 87.335(1)°, V = 1409.2 Å, Z = 4, Rgt(F) = 0.025, wRref(F) = 0.065, T = 100 K. Source of material Following a published prescription [1], 1.55 mL of Me3SiNEt2 were added dropwise to a solution of 0.72 g TaCl5 in 20 mL diethyl ether/toluene mixture (1:3). The orange solution was allowed to stir at room temperature for 24 h. Afterwards, the solvent was removed in vacuum, which leads to a ruby red solid. This solid was dissolved in dried pentane and stored at 0 °C for 12 h, 030°C for 24 h and −65 °C for 24 h. A broken piece of a red, needle-shaped crystal, which was selected from the cold mother solution, was mounted using a nylon loop for X-ray diffraction. Discussion The title compound was prepared in the course of our investigations on single source precursors for tantalum nitrides and oxidenitrides [2-4]. The characteristic building unit of the molecular structure is a bi-octahedral dimer, with all four of the terminal equatorial positions being occupied by diethyl amido groups. Due to the steric demand of the diethyl amido groups the apical chlorine atomes are moved towards each other. This leads to a characteristic bending, with Cl−Ta−Cl angles ranging between 165° and 172°, also known to occur in tantalum pentachloride [5]. The Ta—Cl and the Ta—N bond lenghts are in acceptable agreement with those for other Ta compounds [2-4,6]. Also, the remaining distances and angles fit very well to the expections. The asymmetric unit contains two crystallographically independent [TaCl3(C4H10N)2]2 molecules. Their centers of gravity form an approximate body centered arrangement within the unit cell. Z. Kristallogr. NCS 224 (2009) 499-500 / DOI 10.1524/ncrs.2009. 0218 499 © by Oldenbourg Wissenschaftsverlag, München Crystal: red fragment, size 0.15 × 0.20 × 0.30 mm Wavelength: Mo K1 radiation (0.71073 Å) ': 83.39 cm−1 Diffractometer, scan mode: SMART APEX I, Bruker AXS, 3 2#max: 68.12° N(hkl)measured, N(hkl)unique: 22085, 11238 Criterion for Iobs, N(hkl)gt: Iobs > 2 "(Iobs), 10717 N(param)refined: 373 Programs: SHELXS-97 [7], SHELXL-97 [8], ATOMS [9] Table 1. Data collection and handling. H(11A) 2i 1.161(4) 0.838(4) 0.211(3) 0.029 H(11B) 2i 1.202(4) 0.694(4) 0.225(3) 0.029 H(12A) 2i 1.009(5) 0.822(4) 0.356(3) 0.040 H(12B) 2i 1.172(5) 0.770(4) 0.372(3) 0.040 H(12C) 2i 1.041(5) 0.684(4) 0.373(3) 0.040 H(13A) 2i 0.849(4) 0.609(4) 0.172(3) 0.030 H(13B) 2i 0.929(4) 0.590(4) 0.274(3) 0.030 H(14A) 2i 1.082(5) 0.544(5) 0.099(4) 0.048 H(14B) 2i 1.005(5) 0.431(5) 0.167(3) 0.048 H(14C) 2i 1.139(6) 0.511(5) 0.185(4) 0.048 H(21A) 2i 0.694(4) 0.804(4) 0.233(3) 0.028 H(21B) 2i 0.579(4) 0.726(4) 0.196(3) 0.028 H(22A) 2i 0.565(5) 0.995(4) 0.167(3) 0.038 H(22B) 2i 0.463(5) 0.910(4) 0.240(3) 0.038 H(22C) 2i 0.448(5) 0.906(4) 0.135(3) 0.038 H(23A) 2i 0.679(5) 0.806(4) −0.050(3) 0.036 H(23B) 2i 0.530(5) 0.808(4) 0.020(3) 0.036 H(24A) 2i 0.720(6) 0.586(5) 0.019(4) 0.054 H(24B) 2i 0.565(6) 0.601(5) −0.026(4) 0.054 H(24C) 2i 0.576(6) 0.592(5) 0.084(4) 0.054 H(31A) 2i 0.625(4) 0.093(3) 0.307(3) 0.024 H(31B) 2i 0.533(4) 0.103(3) 0.398(3) 0.024 H(32A) 2i 0.839(5) 0.107(4) 0.399(3) 0.032 H(32B) 2i 0.756(4) −0.013(4) 0.442(3) 0.032 Table 2. Atomic coordinates and displacement parameters (in Å). Atom Site x y z Uiso