Spin-coupled study of addition reactions of singlet dihalocarbenes with ethene

J J  Blavins; D L  Cooper; P B  Karadakov

doi:10.1002/qua.20081

Spin-coupled study of addition reactions of singlet dihalocarbenes with ethene

J J Blavins, D L Cooper, P B Karadakov

Chemistry

Research output: Contribution to journal › Article › peer-review

Abstract

Modern valence bond theory, in its spin-coupled form, is used to examine the electronic rearrangements that take place during the gas-phase additions of singlet CF2 and of singlet CCl2 to ethene. Both reactions are found to follow homolytic pathways, during which the ethene pi-bond breaks and the orbitals that were originally involved in this bond interact with the singlet orbital pair on the carbene. The formation of the two new sigma bonds that close the cyclopropane ring proceeds in a markedly asynchronous manner, so that the systems attain considerable diradical character, as quantified by the composition of the active-space spin-coupling pattern. The rearrangement of the electron spins from a reactant-like form to one better suited to the product takes place much later in the case of the reaction between CCl2 and ethene than in the corresponding reaction of CF2. (C) 2004 Wiley Periodicals, Inc.

Original language	English
Pages (from-to)	465-472
Number of pages	8
Journal	INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
Volume	98
Issue number	5
DOIs	https://doi.org/10.1002/qua.20081
Publication status	Published - 20 Jun 2004

Keywords

cheletropic addition reactions
transition states
valence bond
spin-coupled
REACTION-PATH
SUBSTITUTED CARBENES
TRANSITION-STATES
CYCLO-ADDITIONS
TRIPLET GAPS
ETHYLENE
METHYLENE
CH2
DICHLOROCARBENE
BOND

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10.1002/qua.20081

Cite this

@article{3ffae92a0ea945f1b4cef95c1cdb5a8a,

title = "Spin-coupled study of addition reactions of singlet dihalocarbenes with ethene",

abstract = "Modern valence bond theory, in its spin-coupled form, is used to examine the electronic rearrangements that take place during the gas-phase additions of singlet CF2 and of singlet CCl2 to ethene. Both reactions are found to follow homolytic pathways, during which the ethene pi-bond breaks and the orbitals that were originally involved in this bond interact with the singlet orbital pair on the carbene. The formation of the two new sigma bonds that close the cyclopropane ring proceeds in a markedly asynchronous manner, so that the systems attain considerable diradical character, as quantified by the composition of the active-space spin-coupling pattern. The rearrangement of the electron spins from a reactant-like form to one better suited to the product takes place much later in the case of the reaction between CCl2 and ethene than in the corresponding reaction of CF2. (C) 2004 Wiley Periodicals, Inc.",

keywords = "cheletropic addition reactions, transition states, valence bond, spin-coupled, REACTION-PATH, SUBSTITUTED CARBENES, TRANSITION-STATES, CYCLO-ADDITIONS, TRIPLET GAPS, ETHYLENE, METHYLENE, CH2, DICHLOROCARBENE, BOND",

author = "Blavins, {J J} and Cooper, {D L} and Karadakov, {P B}",

year = "2004",

month = jun,

day = "20",

doi = "10.1002/qua.20081",

language = "English",

volume = "98",

pages = "465--472",

journal = "INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY",

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number = "5",

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TY - JOUR

T1 - Spin-coupled study of addition reactions of singlet dihalocarbenes with ethene

AU - Blavins, J J

AU - Cooper, D L

AU - Karadakov, P B

PY - 2004/6/20

Y1 - 2004/6/20

N2 - Modern valence bond theory, in its spin-coupled form, is used to examine the electronic rearrangements that take place during the gas-phase additions of singlet CF2 and of singlet CCl2 to ethene. Both reactions are found to follow homolytic pathways, during which the ethene pi-bond breaks and the orbitals that were originally involved in this bond interact with the singlet orbital pair on the carbene. The formation of the two new sigma bonds that close the cyclopropane ring proceeds in a markedly asynchronous manner, so that the systems attain considerable diradical character, as quantified by the composition of the active-space spin-coupling pattern. The rearrangement of the electron spins from a reactant-like form to one better suited to the product takes place much later in the case of the reaction between CCl2 and ethene than in the corresponding reaction of CF2. (C) 2004 Wiley Periodicals, Inc.

AB - Modern valence bond theory, in its spin-coupled form, is used to examine the electronic rearrangements that take place during the gas-phase additions of singlet CF2 and of singlet CCl2 to ethene. Both reactions are found to follow homolytic pathways, during which the ethene pi-bond breaks and the orbitals that were originally involved in this bond interact with the singlet orbital pair on the carbene. The formation of the two new sigma bonds that close the cyclopropane ring proceeds in a markedly asynchronous manner, so that the systems attain considerable diradical character, as quantified by the composition of the active-space spin-coupling pattern. The rearrangement of the electron spins from a reactant-like form to one better suited to the product takes place much later in the case of the reaction between CCl2 and ethene than in the corresponding reaction of CF2. (C) 2004 Wiley Periodicals, Inc.

KW - cheletropic addition reactions

KW - transition states

KW - valence bond

KW - spin-coupled

KW - REACTION-PATH

KW - SUBSTITUTED CARBENES

KW - TRANSITION-STATES

KW - CYCLO-ADDITIONS

KW - TRIPLET GAPS

KW - ETHYLENE

KW - METHYLENE

KW - CH2

KW - DICHLOROCARBENE

KW - BOND

U2 - 10.1002/qua.20081

DO - 10.1002/qua.20081

M3 - Article

SN - 0020-7608

VL - 98

SP - 465

EP - 472

JO - INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY

JF - INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY

IS - 5

ER -