Synthesis, conformational preferences in gas and solution, and molecular gear rotation in 1-(dimethylamino)-1-phenyl-1-silacyclohexane by gas phase electron diffraction (GED), LT NMR and theoretical calculations
作者:Bagrat A. Shainyan、Elena N. Suslova、Tran Dinh Phien、Sergey A. Shlykov、Erich Kleinpeter
DOI:10.1016/j.tet.2018.06.023
日期:2018.8
estimated conformational equilibrium. In solution, low temperature NMR spectroscopy showed analyzable decoalescence of Cipso and C(1,5) carbon signals in 13C NMR spectra at 103 K. Opposite to the gas state in the freon solution employed (CD2Cl2/CHFCl2/CHFCl2 = 1:1:3), which is still liquid at 100 K, the 1-Pheq conformer was found to be the preferred one [(1-Pheq: 1-Phax = 77%: 23%, K = 77/23 = 2.8; −ΔG° = −RT
合成了1-(二甲氨基)-1-苯基-1-硅环己烷1,并通过气相电子衍射(GED),低温13 C NMR光谱和量子化学计算研究了其分子结构和构象性质。所述的优势1 -Ph斧构象异构体(1 -Ph当量:1 -Ph斧20的比率:80%,Δ ģ °(317 K)= -0.87千卡/摩尔)在气相接近理论估计构象平衡。在溶液中,低温NMR光谱表明的C分析的decoalescence本位和C(1,5)碳信号在13在103 K时的13 C NMR光谱。与所用氟利昂溶液中的气体状态相反(CD 2 Cl 2 / CHFCl 2 / CHFCl 2 = 1:1:3),在100 K时仍为液态,是1- Ph eq构象异构体被认为是较好的[(1 -Ph当量:1 -Ph AX = 77%:23%,ķ = 77/23 = 2.8;-Δ ģ °= -R Ť LN ķ(在103 K)= 0.44 ±0.1 kcal /