eprintid: 17986
rev_number: 17
userid: 1419
dir: disk0/00/01/79/86
datestamp: 2013-04-01 20:31:25
lastmod: 2019-02-02 15:56:04
status_changed: 2013-04-01 20:31:25
type: article
metadata_visibility: show
item_issues_count: 0
eprint_status: archive
creators_name: Florio, GM
creators_name: Christie, RA
creators_name: Jordan, KD
creators_name: Zwier, TS
creators_email: 
creators_email: 
creators_email: jordan@pitt.edu
creators_email: 
creators_id: 
creators_id: 
creators_id: JORDAN
creators_id: 
title: Conformational preferences of jet-cooled melatonin: Probing trans- and cis-amide regions of the potential energy surface
ispublished: pub
divisions: sch_as_chemistry
full_text_status: public
abstract: The hormone melatonin (N-acetyl-5-methoxytryptamine) is an indole derivative with a flexible peptide-like side chain attached at the C3 position. Using a combination of two-color resonant two-photon ionization (2C-R2PI), laser-induced fluorescence excitation (LIF), resonant ion-dip infrared spectroscopy (RIDIRS), fluorescence-dip infrared spectroscopy (FDIRS), and UV-UV hole-burning spectroscopy, the conformational preferences of melatonin in a molecular beam have been determined. Three major transamide conformers and two minor cis-amide conformers have been identified in the R2PI spectrum and characterized with RIDIRS and FDIRS. Structural assignments are made using the infrared spectra in concert with density functional theory and localized MP2 calculations. Observation of cis-amide melatonin conformers in the molecular beam, despite the large energy gap (∼3 kcal/mol) between trans- and cis-amides, is striking because there are at least nine lower-energy trans-amide minima that are not detected. The implications of this observation for cooling and trapping conformational population in a supersonic expansion are discussed.
date: 2002-08-28
date_type: published
publication: Journal of the American Chemical Society
volume: 124
number: 34
pagerange: 10236 - 10247
refereed: TRUE
issn: 0002-7863
id_number: 10.1021/ja0265916
pmid: 12188688
citation:   Florio, GM and Christie, RA and Jordan, KD and Zwier, TS  (2002) Conformational preferences of jet-cooled melatonin: Probing trans- and cis-amide regions of the potential energy surface.  Journal of the American Chemical Society, 124 (34).  10236 - 10247.  ISSN 0002-7863     
document_url: http://d-scholarship-dev.library.pitt.edu/17986/1/licence.txt