Quantitative photoexcitation and fluorescence studies of C2H2 in vacuum ultraviolet
Quantitative photoexcitation and fluorescence studies of C2H2 in vacuum ultraviolet
复制标题
真空紫外下C2H2的定量光激发和荧光研究
DOI：
10.1063/1.446503
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发表时间：
1984
影响因子：
4.4
通讯作者：
L. C. Lee
中科院分区：
文献类型：
--
作者：
M. Suto;L. C. Lee
用同步辐射光源在105-155 nm范围内测量了乙炔分子的光吸收截面和荧光截面。在106- 136.5nm（阈值）区域测量了由C2 H2的光解离产生C2 H * 荧光的量子产率。吸收光谱显示出尖锐的里德堡态，但量子产率是激发波长的平滑函数。利用量子产率数据导出了C2 H2解离成C2 H +H的准双原子排斥势曲线。研究了C_2H_2、N_2和Ar对C_2H ~* 荧光的猝灭作用。辐射寿命猝灭速率常数的乘积随着激发波长的增加而增加，对于N2和Ar作为猝灭剂，从110 nm处的10−16 cm 3变化到134 nm处的5.5×10−16 cm 3。寿命、猝灭和荧光光谱的数据表明，C2 H * 荧光的上态是良好结合的，而下态是排斥或弱结合态。
The photoabsorption and fluorescence cross sections of C2H2 were measured in the 105–155 nm region using synchrotron radiation as a light source. The quantum yield for producing the C2H* fluorescence from photodissociation of C2H2 was measured in the 106–136.5 nm (threshold) region. The absorption spectrum shows sharp Rydberg states, but the quantum yield is a smooth function of excitation wavelength. The quantum yield data were used to derive a quasidiatomic repulsive potential curve for dissociation of C2H2 into C2H*+H. The quenching of the C2H* fluorescence by C2H2, N2, and Ar was studied. The products of radiative lifetime quenching rate constant increase with increasing excitation wavelengths, varying from 10−16 cm3 at 110 nm to 5.5×10−16 cm3 at 134 nm for N2 and Ar as quenchers. The data of lifetimes, quenchings, and fluorescence spectra point to a conclusion that the upper state of the C2H* fluorescence is well bound, and the lower state is a repulsive or weak‐bound state.