Origin of second harmonic generation optical activity of a tryptophan derivative at the air/water interface

Download
  1. Get@NRC: Origin of second harmonic generation optical activity of a tryptophan derivative at the air/water interface (Opens in a new window)
DOIResolve DOI: http://doi.org/10.1063/1.2216696
AuthorSearch for:
TypeArticle
Journal titleThe Journal Of Chemical Physics
Volume125
Issue4
Pages044716–; # of pages: 14
SubjectINDO calculations; molecular orientation; monolayers; nonlinear optical susceptibility; optical harmonic generation; organic compounds; two-photon processes
AbstractSecond harmonic generation optical activity (SHG-OA) of chiral monolayers of the tryptophan derivative Nalpha-(tert-butoxycarbonyl)-tryptophan (BOC-Trp) at an air/water interface has been studied in detail. In combination with previously reported experimental measurements with the fundamental frequency [h-bar]omega=2.20 eV (lambda=564 nm), new measurements with lambda=564 and 800 nm fully characterize the nonlinear susceptibility tensors of chiral and achiral (racemic) monolayers under two-photon resonant and nonresonant conditions of the fundamental frequency. A realistic computational approach including semiempirical, intermediate neglect of differential overlap (ZINDO/S) calculations has been used to calculate the nonlinear susceptibilities of model achiral and chiral monolayers composed of indole chromophores. There is satisfactory agreement between calculated and observed nonlinear susceptibilities, which constrains certain structural parameters of the monolayers including the absolute orientation of the long molecular axis of indole at the air/water interface. The origin of SHG-OA of BOC-Trp monolayers is discussed with reference of two distinct mechanisms at the microscopic level, designated type I or chiral assembly and type II or electronic coupling. Both mechanisms are studied in detail within the framework of ZINDO/S calculations. The dominant effect for the BOC-Trp monolayers is type I, involving chiral assembly of indole chromophores.
Publication date
LanguageEnglish
AffiliationNational Research Council Canada; NRC Steacie Institute for Molecular Sciences
Peer reviewedNo
NPARC number12328454
Export citationExport as RIS
Report a correctionReport a correction
Record identifierf6306695-451a-44b3-af93-2c7fd9904857
Record created2009-09-10
Record modified2016-05-09
Bookmark and share
  • Share this page with Facebook (Opens in a new window)
  • Share this page with Twitter (Opens in a new window)
  • Share this page with Google+ (Opens in a new window)
  • Share this page with Delicious (Opens in a new window)