Near-infrared excited Raman optical activity.
Measurements of near-infrared scattered circular polarization Raman optical activity (SCP-ROA) are presented using laser excitation at 780 nm for samples of S-(-)-alpha-pinene and L-alanyl-L-alanine. These are the first measurements of ROA outside the blue-to-green visible region between 488 and 532 nm. Comparison of Raman and ROA intensities measured with excitation at 532 and 780 nm demonstrate that the expected frequency to the fourth-power dependence for Raman scattering and the corresponding fifth-power dependence for ROA are observed. It can be concluded that, to within this frequency dependence, the same level of efficiency of Raman and ROA measurements using commercial instrumentation with 532 nm excitation is maintained with the change to near-infrared excitation at 780 nm.
Nafie
Laurence A
LA
Department of Chemistry, Syracuse University, Syracuse, New York 13244-4100, USA. lnafie@syr.edu
Brinson
Bruce E
BE
Cao
Xiaolin
X
Rice
David A
DA
Rahim
Omar M
OM
Dukor
Rina K
RK
Halas
Naomi J
NJ
D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013055:Spectrophotometry, Infrared / Q000379:methods*; D013059:Spectrum Analysis, Raman / Q000379:methods*