Intramolecular triarylmethane-triarylmethylium complex: Generation, properties, and X-ray structure of a C-H bridged carbocation

Takanori Suzuki; Takashi Takeda; Yasuyo Yoshimoto; Takayuki Nagasu; Hidetoshi Kawai; Kenshu Fujiwara

doi:10.1351/PAC-CON-09-10-11

Intramolecular triarylmethane-triarylmethylium complex: Generation, properties, and X-ray structure of a C-H bridged carbocation

Takanori Suzuki, Takashi Takeda, Yasuyo Yoshimoto, Takayuki Nagasu, Hidetoshi Kawai, Kenshu Fujiwara

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

5 Citations (Scopus)

Abstract

A series of title carbocations was generated and isolated as stable salts. X-ray analyses revealed a preference for an unsymmetric structure in which the bridging hydrogen is localized on one of the two triarylmethane units. NMR spectroscopy showed a similar preference in solution. The bridging hydrogen fluctuates between the two chromophores in solution, and the energy barrier for the H shift is linearly correlated with the C⋯C⁺ separation determined by X-ray. According to an extrapolation, the energy barrier should decrease when the C⋯C⁺ separation is less than 2.7 Å, which suggests a new model for isolable pure organic species with a three-center-two-electron bond.

Original language	English
Pages (from-to)	1033-1044
Number of pages	12
Journal	Pure and Applied Chemistry
Volume	82
Issue number	4
DOIs	https://doi.org/10.1351/PAC-CON-09-10-11
Publication status	Published - 2010 May 10
Externally published	Yes

Keywords

Carbocation
Hydride shift
Isotope effects
Neighboring effects
Three-center bond
Triarylmethylium
X-ray structure

ASJC Scopus subject areas

Chemistry(all)
Chemical Engineering(all)

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10.1351/PAC-CON-09-10-11

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abstract = "A series of title carbocations was generated and isolated as stable salts. X-ray analyses revealed a preference for an unsymmetric structure in which the bridging hydrogen is localized on one of the two triarylmethane units. NMR spectroscopy showed a similar preference in solution. The bridging hydrogen fluctuates between the two chromophores in solution, and the energy barrier for the H shift is linearly correlated with the C⋯C+ separation determined by X-ray. According to an extrapolation, the energy barrier should decrease when the C⋯C+ separation is less than 2.7 {\AA}, which suggests a new model for isolable pure organic species with a three-center-two-electron bond.",

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T2 - Generation, properties, and X-ray structure of a C-H bridged carbocation

AU - Suzuki, Takanori

AU - Takeda, Takashi

AU - Yoshimoto, Yasuyo

AU - Nagasu, Takayuki

AU - Kawai, Hidetoshi

AU - Fujiwara, Kenshu

PY - 2010/5/10

Y1 - 2010/5/10

N2 - A series of title carbocations was generated and isolated as stable salts. X-ray analyses revealed a preference for an unsymmetric structure in which the bridging hydrogen is localized on one of the two triarylmethane units. NMR spectroscopy showed a similar preference in solution. The bridging hydrogen fluctuates between the two chromophores in solution, and the energy barrier for the H shift is linearly correlated with the C⋯C+ separation determined by X-ray. According to an extrapolation, the energy barrier should decrease when the C⋯C+ separation is less than 2.7 Å, which suggests a new model for isolable pure organic species with a three-center-two-electron bond.

AB - A series of title carbocations was generated and isolated as stable salts. X-ray analyses revealed a preference for an unsymmetric structure in which the bridging hydrogen is localized on one of the two triarylmethane units. NMR spectroscopy showed a similar preference in solution. The bridging hydrogen fluctuates between the two chromophores in solution, and the energy barrier for the H shift is linearly correlated with the C⋯C+ separation determined by X-ray. According to an extrapolation, the energy barrier should decrease when the C⋯C+ separation is less than 2.7 Å, which suggests a new model for isolable pure organic species with a three-center-two-electron bond.

KW - Carbocation

KW - Hydride shift

KW - Isotope effects

KW - Neighboring effects

KW - Three-center bond

KW - Triarylmethylium

KW - X-ray structure

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Intramolecular triarylmethane-triarylmethylium complex: Generation, properties, and X-ray structure of a C-H bridged carbocation

Abstract

Keywords

ASJC Scopus subject areas

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