Ne-N_2O复合物超声分子束中红外光谱研究

The Supersonic Mid-infrared Spectra of the Ne-N_2O Complex

利用中红外可调谐二极管激光光谱仪,在多程吸收池中接入脉冲超声喷射系统,研究了Ne-N2O van derWaals复合物在N2O单体ν1振动带的振动转动光谱,运用光谱预测程序SPCAT和分子参数拟合程序SPFIT及谱线拟合程序Wang程序拟合出了Ne-N2O的ν2带的振转分子常数,并计算了出结构参数R、θ、ΔI。结果表明,所探测到的20 Ne-N2O的29条、22 Ne-N2O的15条高分辨谱线被准确地标识为Ne-N2Oν2振动转动光谱;20 Ne-N2O和22 Ne-N2O van der Waals复合物均为近T型结构,惰性气体分子和N2O分子质心的连线略微偏向N2O分子的氧原子方向;复合物ν2振动带的带头分别为ν0=1285.12236(9)cm-1和ν0=1285.12299(21)cm-1,与N2O单体的ν1振转谱带的带头相比较,带头蓝移0.21906(10)cm-1和0.21969(22)cm-1。

The rovibrational spectrum of the Ne-N2O van der Waals complex is recorded in the N2O-monomer ν1 region(~1285cm-1) by using an infrared tunable diode laser spectrometer in conjunction with a free supersonic jet expansion and an astigmatic multi-pass absorption cell.Twenty-nine lines of 20Ne-N2O and fifteen lines of 22Ne-N2O are assigned to the ν2-band of Ne-N2O.Rotational constants for the ν2-excited state are derived with the SPFIT program.The structural parameters R,θ,ΔI are calculated.These results show that Ne-N2O complex has similar T-shaped configuration in which the rare gas atom prefers to lie near the oxygen side of N2O.The band-origin of the spectrum is determined to be ν0 = 1285.12236(9)cm-1 for 20Ne-N2O and 1285.12299(21) cm-1 for 22Ne-N2O,shows a blue-shift 0.21906(10)cm-1 for 20Ne-N2O and 0.21969(22) for 22Ne-N2O compared with the N2O ν1-band origin.