摘要
利用激光光解时间分辨富里叶红外发射谱对N_2O在193nm光解进行了研究,观察激光光解后30μs至600μs次级反应产物NO(v)的红外发射谱及其变化,其振动量子数v高达11,反应是通过初级光解产物O(~1D)原子与N-N-O中末端N“头对头”碰撞进行的。利用计算机进行光谱模拟,得到NO(v)各振动态的布居及随时间的演变,由此求出NO(v<11)的各不同振动态与N_2O的传能常数,对所求k_v(v=1-11)用SSH理论进行了分析。发现v=1-4主要进行向N_2O的v_3振动模传能,而v=5-11的NO分子,则向N_2O的v_1模转移能量,其传能几率P_v可用P_v/V=exp(-a_1×|△E_1|-b_1)+exp(-a_2×|△E_2|-b_2)表达。式中|△E_1|,|△E_2|分别是NO(v)与N_2O(000→001),NO(v)与N_2O(000→100)传能时的能量差(cm^(-1)),a_1=0.0170cm,b_1=2.50,a_2=0.0115cm,b_2=3.51。对文献中CO(v=4-13)与CO_2,N_2O的传能常数也进行了类似的分析。
The Photodissociation of N_2O at 193nm has been investigated by time-resolved Fourier transform infrared emission spectroscopy. The emission spectra of NO(v) from the sequential reaction with 30/μs to 600/μs delay were recorded. The vibrational quantum number v was observed as high as 11. The result agrees with the head-on reaction mechanism of O(~1D)and N-N-O. By means of simulated spectra, the vibrational population of NO(v) and its time evolution were obtained, therefore the V-V energy transfer rate constants for NO(v=1-11) by N_2O were calculated. These rate constants were analyzed through SSH theory. We found for v=1-4NO(v)+N_2O(000)→NO(v—1)+N_2O(001)—|ΔE_1|(cm^(-1))is predominant, for v=5—11NO(v)+N_2O(000)→NO(v—1)+N_2O(100)+|ΔE_2|(cm^(-1))is the major energy transfer process. Its energy transfer probability P_v can be express as following:P_v/v = exp(-a_1 x|ΔE_1|-b_1)+exp(-a_2×|ΔE_2|-b_2)a_1, a_2, b_1, b_2 are constants for corresponding processes.a_1=0.0170cm, b_1=2.50, a_2=0.0115cm,b_2=3.51. We also analyzed V-V energy transfer rate cnstants for CO(v=4-13) by CO_2 and by N_2O in literature similarly.
基金
国家自然科学基金
