Theoretical Models for Mechanism and Catalysis in Carbonyl Addition

Ian H. Williams, Gerald M. Maggiora, Richard L. Schowen

Research output: Contribution to journalArticle

Abstract

Exploration of potential energy curves, calculated by ab initio procedures at the STO-3G and 4-31G levels, for the systems H2O + CH2O, HO- + CH2O, and H2O + CH2OH+ produces models for enforced concertedness of proton transfer and heavy-atom reorganization (in the H2O + CH2O reaction) and specific-acid-base catalysis (in the two ion-molecule reactions). Thus, in the former case, approach of water to formaldehyde along such directions as to allow formation of the zwitterionic intermediate compound H2O+CH2O- gives rise to a completely repulsive interaction, so that this structure does not exist as a bound species. A transition state for four-center, concerted addition does, however, exist, and reaction through this state is enforced by nonexistence of the intermediate required along the alternative stepwise route. In the ion-molecule reactions, prior protonation of formaldehyde or prior deprotonation of water leads to formation of the corresponding ionic adducts (H20+CH20H and H0CH20”), with no barrier to reaction, simulating specific-acid and -base catalysis, respectively.

Original languageEnglish
Pages (from-to)7831-7839
Number of pages9
JournalJournal of the American Chemical Society
Volume102
Issue number27
DOIs
Publication statusPublished - 1 Dec 1980

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

Cite this

Theoretical Models for Mechanism and Catalysis in Carbonyl Addition. / Williams, Ian H.; Maggiora, Gerald M.; Schowen, Richard L.

In: Journal of the American Chemical Society, Vol. 102, No. 27, 01.12.1980, p. 7831-7839.

Research output: Contribution to journalArticle

Williams, Ian H. ; Maggiora, Gerald M. ; Schowen, Richard L. / Theoretical Models for Mechanism and Catalysis in Carbonyl Addition. In: Journal of the American Chemical Society. 1980 ; Vol. 102, No. 27. pp. 7831-7839.
@article{e7e3c7c730ce41c09f39143e9920c4d0,
title = "Theoretical Models for Mechanism and Catalysis in Carbonyl Addition",
abstract = "Exploration of potential energy curves, calculated by ab initio procedures at the STO-3G and 4-31G levels, for the systems H2O + CH2O, HO- + CH2O, and H2O + CH2OH+ produces models for enforced concertedness of proton transfer and heavy-atom reorganization (in the H2O + CH2O reaction) and specific-acid-base catalysis (in the two ion-molecule reactions). Thus, in the former case, approach of water to formaldehyde along such directions as to allow formation of the zwitterionic intermediate compound H2O+CH2O- gives rise to a completely repulsive interaction, so that this structure does not exist as a bound species. A transition state for four-center, concerted addition does, however, exist, and reaction through this state is enforced by nonexistence of the intermediate required along the alternative stepwise route. In the ion-molecule reactions, prior protonation of formaldehyde or prior deprotonation of water leads to formation of the corresponding ionic adducts (H20+CH20H and H0CH20”), with no barrier to reaction, simulating specific-acid and -base catalysis, respectively.",
author = "Williams, {Ian H.} and Maggiora, {Gerald M.} and Schowen, {Richard L.}",
year = "1980",
month = "12",
day = "1",
doi = "10.1021/ja00547a001",
language = "English",
volume = "102",
pages = "7831--7839",
journal = "Journal of the American Chemical Society",
issn = "0002-7863",
publisher = "American Chemical Society",
number = "27",

}

TY - JOUR

T1 - Theoretical Models for Mechanism and Catalysis in Carbonyl Addition

AU - Williams, Ian H.

AU - Maggiora, Gerald M.

AU - Schowen, Richard L.

PY - 1980/12/1

Y1 - 1980/12/1

N2 - Exploration of potential energy curves, calculated by ab initio procedures at the STO-3G and 4-31G levels, for the systems H2O + CH2O, HO- + CH2O, and H2O + CH2OH+ produces models for enforced concertedness of proton transfer and heavy-atom reorganization (in the H2O + CH2O reaction) and specific-acid-base catalysis (in the two ion-molecule reactions). Thus, in the former case, approach of water to formaldehyde along such directions as to allow formation of the zwitterionic intermediate compound H2O+CH2O- gives rise to a completely repulsive interaction, so that this structure does not exist as a bound species. A transition state for four-center, concerted addition does, however, exist, and reaction through this state is enforced by nonexistence of the intermediate required along the alternative stepwise route. In the ion-molecule reactions, prior protonation of formaldehyde or prior deprotonation of water leads to formation of the corresponding ionic adducts (H20+CH20H and H0CH20”), with no barrier to reaction, simulating specific-acid and -base catalysis, respectively.

AB - Exploration of potential energy curves, calculated by ab initio procedures at the STO-3G and 4-31G levels, for the systems H2O + CH2O, HO- + CH2O, and H2O + CH2OH+ produces models for enforced concertedness of proton transfer and heavy-atom reorganization (in the H2O + CH2O reaction) and specific-acid-base catalysis (in the two ion-molecule reactions). Thus, in the former case, approach of water to formaldehyde along such directions as to allow formation of the zwitterionic intermediate compound H2O+CH2O- gives rise to a completely repulsive interaction, so that this structure does not exist as a bound species. A transition state for four-center, concerted addition does, however, exist, and reaction through this state is enforced by nonexistence of the intermediate required along the alternative stepwise route. In the ion-molecule reactions, prior protonation of formaldehyde or prior deprotonation of water leads to formation of the corresponding ionic adducts (H20+CH20H and H0CH20”), with no barrier to reaction, simulating specific-acid and -base catalysis, respectively.

UR - http://www.scopus.com/inward/record.url?scp=33847085517&partnerID=8YFLogxK

U2 - 10.1021/ja00547a001

DO - 10.1021/ja00547a001

M3 - Article

VL - 102

SP - 7831

EP - 7839

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 27

ER -