OSA's Digital Library

Applied Spectroscopy

Applied Spectroscopy

| PUBLISHED BY SAS — AVAILABLE FROM SAS AND OSA

  • Vol. 50, Iss. 5 — May. 1, 1996
  • pp: 630–641

Electronic and Vibrational Circular Dichroism of Model β-Lactams: 3-Methyl- and 4-Methylazetidin-2-one

Jennifer McCann, Arvi Rauk, Gennadii V. Shustov, Hal Wieser, and Danya Yang

Applied Spectroscopy, Vol. 50, Issue 5, pp. 630-641 (1996)


View Full Text Article

Acrobat PDF (1208 KB)





Browse Journals / Lookup Meetings

Browse by Journal and Year


   


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools

Share
Citations
  • Export Citation/Save Click for help

Abstract

The chiroptieal properties of the simplest chiral β-lactams, 3- and 4-methylazetidin-2-one, 1 and 2, respectively, were investigated. The experimental vibrational circular dichroism (VCD) and electronic circular dichroism (ECD) spectra were measured and compared with ab initio predictions. Both compounds were found to form dimers with calculated binding enthalpies and free energies of about −51 k J/tool and −6 to −8 kJ/mol, respectively. The experimentally measured IR and VCD spectra were measured in concentrated non-polar (CCI4) solution and are in agreement with the predicted IR and VCD spectra of the dimeric forms, 12 and 22, but not the monomers. The most intense dimer VCD bands originate from in-plane N–H wags, which perturb the H-bonded cyclic array. At the more dilute concentrations employed for the ECD spectra, the experimental ECD spectra in heptane were interpreted satisfactorily as arising from a mixture consisting predominantly of monomers. In protic solvent (H2O, MeOH), the ECD spectra are consistent with H-bonded monomers. Simple modeling suggests that the rotational strengths of the first electronic transition gain most of their intensity from the nonplanarity of the amide chromophore, the contributions of which follow a spiral rule previously enunciated.

Citation
Jennifer McCann, Arvi Rauk, Gennadii V. Shustov, Hal Wieser, and Danya Yang, "Electronic and Vibrational Circular Dichroism of Model β-Lactams: 3-Methyl- and 4-Methylazetidin-2-one," Appl. Spectrosc. 50, 630-641 (1996)
http://www.opticsinfobase.org/as/abstract.cfm?URI=as-50-5-630

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

If you are accessing the full text through a member bundle, please use the Enhanced HTML link to gain access to the citation lists and other restricted features. Note that accessing both the PDF and HTML versions of an article will count as only one download against your account.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

If you are accessing the full text through a member bundle, please use the Enhanced HTML link to gain access to the citation lists and other restricted features. Note that accessing both the PDF and HTML versions of an article will count as only one download against your account.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited