Skip to main content
Advertisement

Main menu

  • Home
  • Articles
    • Current Issue
    • Fast Forward
    • Latest Articles
    • Special Sections
    • Archive
  • Information
    • Instructions to Authors
    • Submit a Manuscript
    • FAQs
    • For Subscribers
    • Terms & Conditions of Use
    • Permissions
  • Editorial Board
  • Alerts
    • Alerts
    • RSS Feeds
  • Virtual Issues
  • Feedback
  • Submit
  • Other Publications
    • Drug Metabolism and Disposition
    • Journal of Pharmacology and Experimental Therapeutics
    • Molecular Pharmacology
    • Pharmacological Reviews
    • Pharmacology Research & Perspectives
    • ASPET

User menu

  • My alerts
  • Log in
  • My Cart

Search

  • Advanced search
Molecular Pharmacology
  • Other Publications
    • Drug Metabolism and Disposition
    • Journal of Pharmacology and Experimental Therapeutics
    • Molecular Pharmacology
    • Pharmacological Reviews
    • Pharmacology Research & Perspectives
    • ASPET
  • My alerts
  • Log in
  • My Cart
Molecular Pharmacology

Advanced Search

  • Home
  • Articles
    • Current Issue
    • Fast Forward
    • Latest Articles
    • Special Sections
    • Archive
  • Information
    • Instructions to Authors
    • Submit a Manuscript
    • FAQs
    • For Subscribers
    • Terms & Conditions of Use
    • Permissions
  • Editorial Board
  • Alerts
    • Alerts
    • RSS Feeds
  • Virtual Issues
  • Feedback
  • Submit
  • Visit molpharm on Facebook
  • Follow molpharm on Twitter
  • Follow molpharm on LinkedIn
Research ArticleArticle

Quantum Mechanical Calculation of Stability in 2-Formyl N-Methyl Pyridinium (Cation) Oxime (2-PAM+) Conformers

WALLY GIORDANO, JON R. HAMANN, JEROME J. HARKINS and JOYCE J. KAUFMAN
Molecular Pharmacology July 1967, 3 (4) 307-317;
WALLY GIORDANO
Medical Research Laboratory, USAEARL, Edgewood Arsenal, Maryland; Chemistry Department, New York University, Washington Square, New York, New York; Physics Department, Research Institute for Advanced Studies (RIAS), Martin Company, Baltimore, Maryland
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
JON R. HAMANN
Medical Research Laboratory, USAEARL, Edgewood Arsenal, Maryland; Chemistry Department, New York University, Washington Square, New York, New York; Physics Department, Research Institute for Advanced Studies (RIAS), Martin Company, Baltimore, Maryland
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
JEROME J. HARKINS
Medical Research Laboratory, USAEARL, Edgewood Arsenal, Maryland; Chemistry Department, New York University, Washington Square, New York, New York; Physics Department, Research Institute for Advanced Studies (RIAS), Martin Company, Baltimore, Maryland
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
JOYCE J. KAUFMAN
Medical Research Laboratory, USAEARL, Edgewood Arsenal, Maryland; Chemistry Department, New York University, Washington Square, New York, New York; Physics Department, Research Institute for Advanced Studies (RIAS), Martin Company, Baltimore, Maryland
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • Article
  • Info & Metrics
  • eLetters
  • PDF
Loading

Abstract

1. Twelve conformers of 2-formyl N-methyl pyridinium (cation) oxime (2-PAM+) were geometrically defined and were subjected to extended Hückel molecular orbital (XHMO) quantum mechanical calculation.

2. The parameter molecular total overlap population (MTOP) was described and was shown to reflect stability and, in this study, to predict expected geometry.

3. By analyzing total energy (TE) and molecular total overlap population (MTOP), within the limitations of the conditions used and the validity of the approximations in the model chosen, the least stable isomers were found to be the two planar oxime-trans pairs (N1T_ and N3T_); the most stable planar isomers were found to be those with oxime syn (cis), and of these the proton pair with aldoxime nitrogen vicinal to ring three (N3S_) was found to be slightly more stable than its ring counterpart (N1S_); the most stable of all conformers were found to be the aldoxime out of plane (OOP) quartet; for any rotational state the syn (cis) oxime configuration was found to be more stable than its respective anti (trans) analog; for any nonsterically hindered aldoxime-ring rotational and oxime configurational state the proton anti (trans) configurational state was found to be more stable than its proton syn (cis) analog.

4. By evaluating differences in the same parameters used above, barriers to rotation, conformation, and configuration were estimated and the energetic implications suggested were deemed significant to consider that the most stable conformers are likely to retain their identity at room temperature in slightly acidic solution (their protonated states).

5. The feasibility, implicit in an earlier study, of theoretically determining conformational stability, barriers to rotation, conformation, and configurational stereoisomerism of molecules in the free molecular state (and possibly in dilute solution) is partially and tentatively substantiated.

6. Although by using total energy (TE) alone, the expected geometry was not predictable from the three aldoxime-ring bond lengths chosen, molecular total overlap populations (MTOP’s) clearly indicated that maximal stability should occur between 1.40 Å and 1.55 Å for planar conformers and very close to 1.55 Å for OOP conformers. This finding may generally imply that any molecule can have its exact geometry accurately predicted by theoretical calculations alone.

7. The use of structures derived from crystallography in the stereochemical and quantum chemical analysis of chemical reactivity in solution is suggested at least at times to be precarious.

ACKNOWLEDGMENT Very warm and special thanks are rendered to Professor Bodil Jerslev for kind and illuminating communications. The technical assistance in data compilation of Betty Wallet, Robert Montgomery, Andrew Westling, Margaret Dalton, Lorraine Hensley, Shirley Hinegardener, Betty Manthei, Toni Caron, and Linda Grimm is gratefully appreciated. The work in developing the programs used in these studies was supported in part by the Air Force Office of Scientific Research of the Office of Aerospace Research under contract AF49(638)-1530. These studies were supported in part by Department of the Army Contract Number DA-18-035-AMC-745(A).

  • Copyright ©, 1967, by Academic Press Inc.

MolPharm articles become freely available 12 months after publication, and remain freely available for 5 years. 

Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page. 

 

  • Click here for information on institutional subscriptions.
  • Click here for information on individual ASPET membership.

 

Log in using your username and password

Forgot your user name or password?

Purchase access

You may purchase access to this article. This will require you to create an account if you don't already have one.
PreviousNext
Back to top

In this issue

Molecular Pharmacology
Vol. 3, Issue 4
1 Jul 1967
  • Table of Contents
  • Table of Contents (PDF)
  • Index by author
  • Editorial Board (PDF)
Download PDF
Article Alerts
Sign In to Email Alerts with your Email Address
Email Article

Thank you for sharing this Molecular Pharmacology article.

NOTE: We request your email address only to inform the recipient that it was you who recommended this article, and that it is not junk mail. We do not retain these email addresses.

Enter multiple addresses on separate lines or separate them with commas.
Quantum Mechanical Calculation of Stability in 2-Formyl N-Methyl Pyridinium (Cation) Oxime (2-PAM+) Conformers
(Your Name) has forwarded a page to you from Molecular Pharmacology
(Your Name) thought you would be interested in this article in Molecular Pharmacology.
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
Citation Tools
Research ArticleArticle

Quantum Mechanical Calculation of Stability in 2-Formyl N-Methyl Pyridinium (Cation) Oxime (2-PAM+) Conformers

WALLY GIORDANO, JON R. HAMANN, JEROME J. HARKINS and JOYCE J. KAUFMAN
Molecular Pharmacology July 1, 1967, 3 (4) 307-317;

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero

Share
Research ArticleArticle

Quantum Mechanical Calculation of Stability in 2-Formyl N-Methyl Pyridinium (Cation) Oxime (2-PAM+) Conformers

WALLY GIORDANO, JON R. HAMANN, JEROME J. HARKINS and JOYCE J. KAUFMAN
Molecular Pharmacology July 1, 1967, 3 (4) 307-317;
del.icio.us logo Digg logo Reddit logo Twitter logo Facebook logo Google logo Mendeley logo
  • Tweet Widget
  • Facebook Like
  • Google Plus One

Jump to section

  • Article
  • Info & Metrics
  • eLetters
  • PDF

Related Articles

Cited By...

More in this TOC Section

  • Polypharmacology of CBL0137 in the African Trypanosome
  • Peptide-mediated differential signaling at GPR83
  • Therapeutic Effects of FGF23 Antagonists in Hyp Mice
Show more Articles

Similar Articles

Advertisement
  • Home
  • Alerts
Facebook   Twitter   LinkedIn   RSS

Navigate

  • Current Issue
  • Fast Forward by date
  • Fast Forward by section
  • Latest Articles
  • Archive
  • Search for Articles
  • Feedback
  • ASPET

More Information

  • About Molecular Pharmacology
  • Editorial Board
  • Instructions to Authors
  • Submit a Manuscript
  • Customized Alerts
  • RSS Feeds
  • Subscriptions
  • Permissions
  • Terms & Conditions of Use

ASPET's Other Journals

  • Drug Metabolism and Disposition
  • Journal of Pharmacology and Experimental Therapeutics
  • Pharmacological Reviews
  • Pharmacology Research & Perspectives
ISSN 1521-0111 (Online)

Copyright © 2022 by the American Society for Pharmacology and Experimental Therapeutics