The 1,1ʹ-Ethylenebis[4-(methoxycarbonyl)pyridinyl] Diradical and Its Photosensitive Cyclomers

Yusaku Ikegami; Takashi Muramatsu; Kaoru Hanava; Shinji Onodera; Norio Nakayama; Edward M. Kosower

doi:10.1021/ja00244a003

The 1,1ʹ-Ethylenebis[4-(methoxycarbonyl)pyridinyl] Diradical and Its Photosensitive Cyclomers

Yusaku Ikegami, Takashi Muramatsu, Kaoru Hanava, Shinji Onodera, Norio Nakayama^*, Edward M. Kosower

^*Corresponding author for this work

School of Chemistry

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

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Abstract

One electron reduction of, 1ʹ-ethylenebis[4-(methoxycarbonyl)pyridinium] ion (2²⁺) first gives the cation radical (2^+·), which showed a well-resolved ESR spectrum, and further reduction affords cyclomers formed by intramolecular cyclization of the diradical (2^··). Photodissociation of the cyclomers give 2^··, which was characterized by an ESR triplet spectrum with the zero field parameters,|D|= 0.0178 and |E| = 0.0017 cm^-1, and also by absorption spectrum. Calculations of the D value suggest that the dihedral angle of the N-CH₂-CH₂-N group of 2^·· in a rigid glass is about 75°. Photolysis of the cyclomer via the πσ* state leads to the diradical through rotation around the ring N-CH₂bond followed by rotation around the CH₂-CH₂bond. Assocation of 2^··to polydiradical π-complexes at low temperature is proposed on the basis of ESR data and confirmed spectroscopically.

Original language	English
Pages (from-to)	2876-2880
Number of pages	5
Journal	Journal of the American Chemical Society
Volume	109
Issue number	10
DOIs	https://doi.org/10.1021/ja00244a003
State	Published - 1 May 1987

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title = "The 1,1ʹ-Ethylenebis[4-(methoxycarbonyl)pyridinyl] Diradical and Its Photosensitive Cyclomers",

abstract = "One electron reduction of, 1ʹ-ethylenebis[4-(methoxycarbonyl)pyridinium] ion (22+) first gives the cation radical (2+·), which showed a well-resolved ESR spectrum, and further reduction affords cyclomers formed by intramolecular cyclization of the diradical (2··). Photodissociation of the cyclomers give 2··, which was characterized by an ESR triplet spectrum with the zero field parameters,|D|= 0.0178 and |E| = 0.0017 cm-1, and also by absorption spectrum. Calculations of the D value suggest that the dihedral angle of the N-CH2-CH2-N group of 2·· in a rigid glass is about 75°. Photolysis of the cyclomer via the πσ* state leads to the diradical through rotation around the ring N-CH2bond followed by rotation around the CH2-CH2bond. Assocation of 2··to polydiradical π-complexes at low temperature is proposed on the basis of ESR data and confirmed spectroscopically.",

author = "Yusaku Ikegami and Takashi Muramatsu and Kaoru Hanava and Shinji Onodera and Norio Nakayama and Kosower, {Edward M.}",

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AU - Ikegami, Yusaku

AU - Muramatsu, Takashi

AU - Hanava, Kaoru

AU - Onodera, Shinji

AU - Nakayama, Norio

AU - Kosower, Edward M.

PY - 1987/5/1

Y1 - 1987/5/1

N2 - One electron reduction of, 1ʹ-ethylenebis[4-(methoxycarbonyl)pyridinium] ion (22+) first gives the cation radical (2+·), which showed a well-resolved ESR spectrum, and further reduction affords cyclomers formed by intramolecular cyclization of the diradical (2··). Photodissociation of the cyclomers give 2··, which was characterized by an ESR triplet spectrum with the zero field parameters,|D|= 0.0178 and |E| = 0.0017 cm-1, and also by absorption spectrum. Calculations of the D value suggest that the dihedral angle of the N-CH2-CH2-N group of 2·· in a rigid glass is about 75°. Photolysis of the cyclomer via the πσ* state leads to the diradical through rotation around the ring N-CH2bond followed by rotation around the CH2-CH2bond. Assocation of 2··to polydiradical π-complexes at low temperature is proposed on the basis of ESR data and confirmed spectroscopically.

AB - One electron reduction of, 1ʹ-ethylenebis[4-(methoxycarbonyl)pyridinium] ion (22+) first gives the cation radical (2+·), which showed a well-resolved ESR spectrum, and further reduction affords cyclomers formed by intramolecular cyclization of the diradical (2··). Photodissociation of the cyclomers give 2··, which was characterized by an ESR triplet spectrum with the zero field parameters,|D|= 0.0178 and |E| = 0.0017 cm-1, and also by absorption spectrum. Calculations of the D value suggest that the dihedral angle of the N-CH2-CH2-N group of 2·· in a rigid glass is about 75°. Photolysis of the cyclomer via the πσ* state leads to the diradical through rotation around the ring N-CH2bond followed by rotation around the CH2-CH2bond. Assocation of 2··to polydiradical π-complexes at low temperature is proposed on the basis of ESR data and confirmed spectroscopically.

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The 1,1ʹ-Ethylenebis[4-(methoxycarbonyl)pyridinyl] Diradical and Its Photosensitive Cyclomers

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