TY  - JOUR
ID  - pittir16151
UR  - http://d-scholarship-dev.library.pitt.edu/16151/
IS  - 44
A1  - Baquero, EE
A1  - James, WH
A1  - Choi, TH
A1  - Jordan, KD
A1  - Zwier, TS
Y1  - 2008/11/06/
N2  - Resonant two-photon ionization (R2PI), UV hole-burning (UVHB), and resonant ion-dip infrared (RIDIR) spectroscopy have been used to study the single-conformation infrared and ultraviolet spectroscopy of 3-(4-hydroxyphenyl)-N-benzylpropionamide (HNBPA, HOC6H 5CH2CH2(C=O)NHCH2C6H 5) cooled in a supersonic expansion. UVHB determines the presence of three conformers, two of which dominate the spectrum. RIDIR spectra in the OH stretch (3600-3700 cm-1), amide NH stretch (3450-3500 cm -1), and C=O stretch (1700-1750 cm-1) regions reveal the presence of small shifts in these fundamentals that are characteristic of the folding of the flexible chain and the ring-ring and ring-chain interactions. On the basis of a comparison of the experimental frequency shifts with calculations, the two major experimentally observed conformers are assigned to two folded structures in which the two aromatic rings are (nominally) face-to-face and perpendicular to one another. The perpendicular structure has a transition assignable to the S0-S2 origin, while the face-to-face structure does not, consistent with a faster nonradiative process in the latter case. The calculated structures and vibrational frequencies are quite sensitive to the level of theory due to the flexibility of the interconnecting chain and the importance of dispersive interactions between the two aromatic rings. © 2008 American Chemical Society.
JF  - Journal of Physical Chemistry A
VL  - 112
SN  - 1089-5639
TI  - Single conformation spectroscopy of a flexible bichromophore: 3-(4-hydroxyphenyl)-N-benzylpropionamide
SP  - 11115 
AV  - public
EP  -  11123
ER  -