Reilly Neil J, Schmidt Timothy W, Kable Scott H
School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia.
J Phys Chem A. 2006 Nov 16;110(45):12355-9. doi: 10.1021/jp064411z.
We report a new application of fluorescence spectroscopy for the identification and characterization of chemical species in complex environments. Simultaneous collection of a dispersed fluorescence spectrum for every step of the laser wavelength results in a two-dimensional spectrum of emission versus excitation wavelengths. This two-dimensional fluorescence (2DF) spectrum yields quick and intuitive assignments of a multitude of peaks in the separate fluorescence excitation and dispersed fluorescence spectra as belonging to the same species. We demonstrate the technique with the measurement of 2DF spectra of a discharge of dilute benzene into a supersonic free jet. A multitude of rovibronic bands due to the C(2) Swan and C(3) comet bands are immediately apparent and even unreported bands can be assigned intuituvely. Custom software filters are employed to enhance or reject emission from one or the other carrier to obtain excitation spectra arising from purely one carrier, or even a specific spectral component of a single carrier. The very characteristic 2DF fingerprints of C(2) and C(3) permit identification of another unidentified species in the discharge that absorbs at 476 nm, coincident with one of the diffuse interstellar bands.
我们报告了荧光光谱法在复杂环境中化学物质识别和表征方面的一种新应用。对激光波长的每一步同时采集分散荧光光谱，可得到发射波长与激发波长的二维光谱。这种二维荧光（2DF）光谱能快速直观地将单独的荧光激发光谱和分散荧光光谱中的众多峰归属于同一物质。我们通过测量稀苯排放到超声速自由射流中的2DF光谱来演示该技术。由于C(2)天鹅带和C(3)彗星带产生的大量振转带立即显现出来，甚至未报道过的谱带也能直观地归属。使用定制的软件滤波器来增强或抑制来自一种或另一种载体的发射，以获得仅来自一种载体甚至单个载体的特定光谱成分的激发光谱。C(2)和C(3)非常独特的2DF指纹图谱使得能够识别放电中另一种未识别的物质，该物质在476nm处吸收，与其中一条弥漫星际带重合。
