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Quantitative and Mechanistic Mechanochemistry in Ferrocene Dissociation.

ABSTRACT: Ferrocene is classically regarded as being highly inert owing to the large dissociation energy of metal-cyclopentadienyl (Cp) bonds. We show that the Fe-Cp bond in ferrocene is the preferential site of mechanochemical scission in the pulsed ultrasonication of main-chain ferrocene-containing polybutadiene-derived polymers. Quantitative studies reveal that the Fe-Cp bond is similar in strength to the carbon-nitrogen bond of an azobisdialkylnitrile (bond dissociation energy < -0 kcal/mol), despite the significantly higher Fe-Cp bond dissociation energy (approximately 90 kcal/mol). Mechanistic studies are consistent with a predominately heterolytic mechanism of chain scission. DFT calculations provide insights into the origins of ferrocene's mechanical lability.

SUBMITTER: Sha Y

PROVIDER: S-EPMC6516481 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature

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Quantitative and Mechanistic Mechanochemistry in Ferrocene Dissociation.

Sha Ye Y Zhang Yudi Y Xu Enhua E Wang Zi Z Zhu Tianyu T Craig Stephen L SL Tang Chuanbing C

ACS macro letters 20180914 10

Ferrocene is classically regarded as being highly inert owing to the large dissociation energy of metal-cyclopentadienyl (Cp) bonds. We show that the Fe-Cp bond in ferrocene is the preferential site of mechanochemical scission in the pulsed ultrasonication of main-chain ferrocene-containing polybutadiene-derived polymers. Quantitative studies reveal that the Fe-Cp bond is similar in strength to the carbon-nitrogen bond of an azobisdialkylnitrile (bond dissociation energy < -0 kcal/mol), despite ...[more]

PMID: 31098336

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