TY - JOUR
T1 - Revealing the Structure and Noncovalent Interactions of Isolated Molecules by Laser-Desorption/Ionization-Loss Stimulated Raman Spectroscopy and Quantum Calculations
AU - Shachar, Afik
AU - Kallos, Itai
AU - De Vries, Mattanjah S.
AU - Bar, Ilana
N1 - Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/11/25
Y1 - 2021/11/25
N2 - The structural and dynamical characteristics of isolated molecules are essential, yet obtaining this information is difficult. We demonstrate laser-desorption jet-cooling/ionization-loss stimulated Raman spectroscopy to obtain Raman spectral signatures of nonvolatile molecules in the gas phase. The vibrational features of a test substance, the most abundant conformer of tryptamine, are compared and found to match those resulting from the scaled harmonic Raman spectrum obtained by density functional theory calculations. The vibrational signatures serve to identify the most prominent gauche conformer and evaluate its predicted electronic structure. These findings, together with noncovalent interaction (NCI) analysis, provide new insights into electron densities and reduced density gradients, assessing the hydrogen bonds (N-H···πand C-H···H-C) and interplay between attractive and repulsive NCIs affecting the structure. This approach accesses vibrational signatures of isolated nonvolatile molecules by tabletop lasers at uniform resolution and in a broad frequency range, promising great benefit to future studies.
AB - The structural and dynamical characteristics of isolated molecules are essential, yet obtaining this information is difficult. We demonstrate laser-desorption jet-cooling/ionization-loss stimulated Raman spectroscopy to obtain Raman spectral signatures of nonvolatile molecules in the gas phase. The vibrational features of a test substance, the most abundant conformer of tryptamine, are compared and found to match those resulting from the scaled harmonic Raman spectrum obtained by density functional theory calculations. The vibrational signatures serve to identify the most prominent gauche conformer and evaluate its predicted electronic structure. These findings, together with noncovalent interaction (NCI) analysis, provide new insights into electron densities and reduced density gradients, assessing the hydrogen bonds (N-H···πand C-H···H-C) and interplay between attractive and repulsive NCIs affecting the structure. This approach accesses vibrational signatures of isolated nonvolatile molecules by tabletop lasers at uniform resolution and in a broad frequency range, promising great benefit to future studies.
UR - http://www.scopus.com/inward/record.url?scp=85119592746&partnerID=8YFLogxK
U2 - 10.1021/acs.jpclett.1c03336
DO - 10.1021/acs.jpclett.1c03336
M3 - Article
C2 - 34767362
AN - SCOPUS:85119592746
SN - 1948-7185
VL - 12
SP - 11273
EP - 11279
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
IS - 46
ER -