Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark.
J Chem Phys. 2012 May 14;136(18):184305. doi: 10.1063/1.4707707.
We have identified the dimethylamine-trimethylamine complex (DMA-TMA) at room temperature in the gas phase. The Fourier transform infrared (FTIR) spectrum of DMA-TMA in the NH-stretching fundamental region was obtained by spectral subtraction of spectra of each monomer. Explicitly correlated coupled cluster calculations were used to determine the minimum energy structure and interaction energy of DMA-TMA. Frequencies and intensities of NH-stretching transitions were also calculated at this level of theory with an anharmonic oscillator local mode model. The fundamental NH-stretching intensity in DMA-TMA is calculated to be approximately 700 times larger than that of the DMA monomer. The measured and calculated intensity is used to determine a room temperature equilibrium constant of DMA-TMA of 1.7 × 10(-3) atm(-1) at 298 K.
我们在室温下气相中鉴定出了二甲胺-三甲胺复合物（DMA-TMA）。通过对每个单体光谱进行光谱减除法得到了 DMA-TMA 在 NH 伸缩基本区域的傅里叶变换红外（FTIR）光谱。我们使用显式相关耦合簇计算来确定 DMA-TMA 的最低能量结构和相互作用能。我们还在该理论水平上使用非谐振荡器局部模式模型计算了 NH 伸缩跃迁的频率和强度。DMA-TMA 的基本 NH 伸缩强度计算值大约是 DMA 单体的 700 倍。所测量和计算的强度用于确定 298 K 时 DMA-TMA 的室温平衡常数为 1.7×10(-3)atm(-1)。
