We obtained resonant two-photon ionization circular dichroism (R2PICD) spectra of jet-cooled phenylalanine (Phe) and its hydrated clusters (Phe(HO), n = 1-2) near the origin band of the S-S transition. The R2PICD spectra of Phe exhibit well-resolved CD bands of six different conformers present in the jet, which vary in sign and magnitude depending on their conformations. We revised the previous structural assignments of the Phe conformers based on the comparison between the experimental and theoretical CD signs, infrared spectra, and rotational band contours. The R2PICD spectra of Phe(HO) reveal that hydration with one or two water molecule(s) does not affect the CD signs of Phe conformers but significantly increases their CD magnitudes. Furthermore, conformational selection by solvation alters relative populations of Phe conformers, leading to a sign inversion in the CD spectra of Phe(HO) compared with that of Phe monomer.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.jpclett.6b01894 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Vibrational Mode-Dependent Circular Dichroism of Jet-Cooled Styrene Oxide.
J Phys Chem Lett
November 2024
Department of Chemistry, Chungbuk National University, Chungbuk 28644, Korea.
Vibrational mode-dependent circular dichroism (CD) effects in vibrational CD spectra are often used to determine the handedness of molecules with multiple chiral centers. Here, we investigate vibrational mode-dependent CD effects in the electronic CD spectra of jet-cooled ()-(+)- and ()-(-)-styrene oxide obtained by using resonant two-photon ionization CD (R2PICD) spectroscopy. Although most fundamental vibronic bands demonstrated CD signatures consistent with that of the origin band, the overtone and combination bands exhibited opposite CD signatures.
View Article and Find Full Text PDFElectronic Circular Dichroism Spectroscopy of Jet-Cooled Phenylalanine and Its Hydrated Clusters.
J Phys Chem Lett
November 2016
Department of Chemistry, Chungbuk National University, Chungbuk 28644, Korea.
We obtained resonant two-photon ionization circular dichroism (R2PICD) spectra of jet-cooled phenylalanine (Phe) and its hydrated clusters (Phe(HO), n = 1-2) near the origin band of the S-S transition. The R2PICD spectra of Phe exhibit well-resolved CD bands of six different conformers present in the jet, which vary in sign and magnitude depending on their conformations. We revised the previous structural assignments of the Phe conformers based on the comparison between the experimental and theoretical CD signs, infrared spectra, and rotational band contours.
View Article and Find Full Text PDFFluorescence-detected circular dichroism spectroscopy of jet-cooled ephedrine.
Phys Chem Chem Phys
March 2016
Department of Chemistry, Chungbuk National University, Chungbuk 28644, Korea.
The resonant two-photon ionization circular dichroism (R2PICD) spectrum represents the cumulative circular dichroism (CD) of one-photon excitation and the subsequent one-photon ionization, whereas the fluorescence-detected circular dichroism (FDCD) spectra exhibit only the CD of one-photon excitation, similar to conventional CD spectra. We obtained the FDCD spectra of jet-cooled ephedrine (EPD) near the origin band of the S0-S1 transition to measure the CD of one-photon absorption and thus the CD of the ionization process in R2PI in comparison with the R2PICD spectra. The CD effects of the ionization following excitation of the A (0-0) and C (930 cm(-1)) bands in the spectrum are small, whereas those of the B band (530 cm(-1)) are anomalously large, leading to opposite CD signs for the FDCD and R2PICD spectra.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!