A thermally robust di-n-butyl thorium complex with an unstable dimethyl analogue (original) (raw)

2010, Dalton Transactions

Ex xp pe er ri im me en nt ta al l S Se ec ct ti io on n (1a) General Details Laboratory Equipment and Apparatus: An argon-filled MBraun UNIlab glove box was employed for the manipulation and storage of all oxygen and moisture sensitive compounds, and all thermally unstable compounds were stored in a-30 o C freezer within the glovebox. Reactions were performed on a double manifold high vacuum line using standard techniques, 1 and all reaction products were thoroughly dried in vacuo. Commonly utilized specialty glassware includes the swivel frit assembly, J-Young NMR tubes, and thick walled flasks equipped with Teflon stopcocks. A Fisher Scientific Ultrasonic FS-30 bath was used to sonicate reaction mixtures where indicated. Residual oxygen and moisture was removed from the argon stream by passage through an Oxisorb-W scrubber from Matheson Gas Products. Solvents: Anhydrous 1,2-dimethoxyethane (dme) and OEt 2 were purchased from Aldrich, and stored over molecular sieves prior to further drying (see below). O(SiMe 3) 2 was purchased from Aldrich, and deuterated solvents were purchased from ACP Chemicals. Hexanes, toluene and THF were initially dried and distilled at atmospheric pressure from CaH 2 , sodium and sodium/benzophenone, respectively. All solvents were stored over an appropriate drying agent (1,2-dme, OEt 2 , THF, d 8-THF toluene, C 6 D 6 = Na/Ph 2 CO; hexanes, O(SiMe 3) 2 = Na/Ph 2 CO/tetraglyme) and introduced to reactions via vacuum transfer with condensation at-78 °C. Instrumentation and details for NMR experiments: Nuclear magnetic resonance spectroscopy (1 H, 13 C{ 1 H}, 13 C, DEPT-135, COSY, HSQC and HMBC experiments) was performed on Bruker DRX-500 and AV-600 spectrometers. All spectra were obtained at room temperature (298K) unless otherwise specified. 1 H NMR and 13 C NMR spectra are referenced relative to SiMe 4 through a resonance of the employed deuterated solvent or proteo impurity of the solvent; C 6 D 6 (δ 7.15 ppm), C 7 D 8 (δ 7.09, 7.00, 6.98, 2.09) and d 8-THF (3.58, 1.73 ppm) for 1 H NMR, and C 6 D 6 (δ 128.0 ppm), C 7 D 8 (δ 137.86, 129.24,