Comparative analysis of linear and non-linear transition state of hydrogen transfer reaction between benzoyl type radicals with skipped alkadienes

Song, Dong Joo; Wu, Bo; Huang, Biyun; Zhang, Yun; Huang, Hong; Liang, Zhiling; Ke, Zhuofeng; Ye, Guodong

doi:10.1016/j.comptc.2016.01.021

Cited by 5 publications

(4 citation statements)

References 24 publications

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“…We found that the structure of unsaturated monomer has a dramatic effect on the activation barrier in hydrogen abstraction reaction19. MO is known as a mono-ene.…”

Section: Resultsmentioning

confidence: 90%

Theoretical and Experimental Study of Light-assisted Polymerization by Multimechanism Action

Zhou

Song

Zhong

et al. 2016

Sci Rep

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A novel bicomponent alkyd system was designed to decrease the usage of Cobalt-based drier due to its latent carcinogensis. The system was polymerized using a Cobalt-salt complex as an air-sensitive drier and an isopropylthioxanthone photoinitiator as a light-sensitive accelerator, as well as using irradiation in the form of visible light. The combined influence of the two additives on autoxidation was analyzed using real-time infrared spectroscopy. The results show that isopropylthioxanthone can increase the efficiency of hydrogen abstraction at the beginning of the curing reaction. A linear free energy relationship was used to theoretically predict the hydrogen abstraction ability of photoinitiators. Nanosecond laser flash photolysis was used to obtain the quenching rate constants between alkyd monomers and isopropylthioxanthone according to the Stern-Volmer equation. The thermodynamic data of transition state theory, such as the activation energy, were calculated by using quantum chemistry program. The reaction rate constant and the Wigner tunneling factor were predicted from the result of quantum chemistry. The vertical excitation energy obtained from the time-dependent density functional theory was used to explain the anomalous behavior of the photoinitiators. These theoretical results fit well with the experimental result of linear free energy relationship. On the basis of these observed results, an accelerated mechanism of the photoassisted autoxidation of alkyd resins was proposed.

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“…We found that the structure of unsaturated monomer has a dramatic effect on the activation barrier in hydrogen abstraction reaction19. MO is known as a mono-ene.…”

Section: Resultsmentioning

confidence: 90%

Theoretical and Experimental Study of Light-assisted Polymerization by Multimechanism Action

Zhou

Song

Zhong

et al. 2016

Sci Rep

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“…According to our observation, the κ (T) value induced by radicals is usually over 3 and it has pronounced impact on the reactivity. 27,28 The rate constant for ortho-(3.52 × 10 −22 cm 3 • molecule −1 •s −1 ) is about one order of magnitude higher than that for meta-(9.07 × 10 −23 cm 3 •molecule −1 •s −1 ) at the B3LYP functional, which also suggests that ortho-is more efficient in the hydrogen abstraction reaction. 2.5.…”

Section: Allyl Monomer Descriptorsmentioning

confidence: 95%

Density Functional Theory Guide for an Allyl Monomer Polymerization Mechanism: Photoinduced Radical-Mediated [3 + 2] Cyclization

et al. 2021

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Polymerization of allyl ether monomers has previously been considered a free-radical addition polymerization mechanism, but it is difficult to achieve because of the high electron density of their double bond. To interpret the mechanism of photopolymerization, we therefore proposed a radical-mediated cyclization (RMC) reaction, which has been validated by results from quantum chemistry calculations and real-time infrared observation. Our RMC reaction begins with the radical abstracting one allylic hydrogen atom from the methylene group of allyl ether to generate an allyl ether radical with a delocalized π 3 3 bond. Then, the radical reacts with the double bond of a second allyl ether molecule to form a fivemembered cyclopentane-like ring (CP) radical. The CP radical abstracts a hydrogen atom from a third ether molecule. At last, a new allyl ether radical is generated and the next circulation as chain propagation begins. The distortion/interaction model was employed to explore the transient state of reaction, and real-time infrared was chosen to clarify the RMC reaction mechanism initiated by different photoinitiators. These results demonstrated that the RMC mechanism can give new insights into these fundamental processes.

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“…The rate constants of the reaction can be calculated from the basic physical properties of the reactants and transition states, such as bond length and nuclear spacing. 30,31 Thus, the transition state theory essentially relates the microscopic molecular structure with the macroscopic reaction rate. By statistical and quantum mechanics, researchers [32][33][34] have successfully calculated the thermodynamic and kinetic parameters such as activation energy and reaction rate constant using a Gaussian software.…”

Section: Introductionmentioning

confidence: 99%

“…According to the transition state theory, the reactants of a reaction may form unstable activated complexes with high potential energy. The rate constants of the reaction can be calculated from the basic physical properties of the reactants and transition states, such as bond length and nuclear spacing 30,31 . Thus, the transition state theory essentially relates the microscopic molecular structure with the macroscopic reaction rate.…”

Section: Introductionmentioning

confidence: 99%

Continuous synthesis of 1‐ethoxy‐2,3‐difluoro‐4‐iodo‐benzene in a microreactor system and the Gaussian and computational fluid dynamics simulations

et al. 2021

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A microreactor system consisting of membrane-dispersion tube-in-tube microreactors and delay loops was developed for the continuous synthesis of 1-ethoxy-2,3-difluoro-4-iodo-benzene. Because of the high mass and heat transfer in the microreactor system, ortho-and halogen-lithiation could be performed at −40 and −20 C, respectively, which are much higher than the temperature required (−70 C) for the batch reaction. In stirred tanks, the yield of 1-ethoxy-2,3-difluoro-4-iodobenzene reaches 91.0% in 70 min. Nearly the same yield of 91.3% was achieved within a shorter time of 16 min in the microreactor system. Furthermore, the kinetics of ortho-lithiation calculated by the Gaussian software, were used for the computational fluid dynamics (CFD) simulations of the reaction process in another microreactor system. Thus, a Gaussian-CFD-coupled-method for efficiently predicting reaction kinetics and yield without experiments could be established. The predicted yield reached 88.7% at 1000 s, which is comparable with the experimental yield of 90.1% at 960 s.

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Comparative analysis of linear and non-linear transition state of hydrogen transfer reaction between benzoyl type radicals with skipped alkadienes

Cited by 5 publications

References 24 publications

Theoretical and Experimental Study of Light-assisted Polymerization by Multimechanism Action

Theoretical and Experimental Study of Light-assisted Polymerization by Multimechanism Action

Density Functional Theory Guide for an Allyl Monomer Polymerization Mechanism: Photoinduced Radical-Mediated [3 + 2] Cyclization

Continuous synthesis of 1‐ethoxy‐2,3‐difluoro‐4‐iodo‐benzene in a microreactor system and the Gaussian and computational fluid dynamics simulations

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