scholarly journals Detailed Molecular Dynamics of the Photochromic Reaction of Spiropyran: A Semiclassical Dynamics Study

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Gaohong Zhai ◽  
Shuai Shao ◽  
Shaomei Wu ◽  
Yibo Lei ◽  
Yusheng Dou
Keyword(s):  
Ring Opening ◽  
Bond Cleavage ◽  
Electron Transition ◽  
Dynamics Simulation ◽  
Theoretical Studies ◽  
Ring Opening Reaction ◽  
Semiclassical Dynamics ◽  
Out Of Plane ◽  
Theoretical Finding ◽  
Photochromic Reaction

A realistic semiclassical dynamics simulation study is reported for the photoinduced ring-opening reaction of spiropyran. The main simulation results show that one pathway involves hydrogen out-of-plane (HOOP) torsion of phenyl ring nearby N atom in 254 fs on the excited state and the isomerization from cis- to trans-SP that is complete in about 10 ps on the ground state after the electron transitionπσ*; the other dominate pathway corresponds to the ring-opening reaction of trans-SP to form the most stable merocyanine (MC) product. Unlike the previous theoretical finding, one C−C bond cleavage on the real molecule rather than the C−N dissociation of the model one is more probable than the ring-opening reaction after the photoexcitation of SP. The simulation findings provide more important complementarity for interpreting experimental observations, confirming the previously theoretical studies of photochromic ring-opening process and even supplying other possible reaction mechanisms.

scholarly journals Correction: Epoxide ring-opening reaction promoted by ionic liquid reactivity: interplay of experimental and theoretical studies

2019 ◽  
Vol 9 (22) ◽  
pp. 6532-6532
Author(s):  
Shengxin Chen ◽  
Guixiang Zeng ◽  
Yingwei Li ◽  
Bin He ◽  
Ruixia Liu ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ring Opening ◽  
Epoxide Ring ◽  
Theoretical Studies ◽  
Epoxide Ring Opening ◽  
Ring Opening Reaction ◽  
Experimental And Theoretical Studies

Correction for ‘Epoxide ring-opening reaction promoted by ionic liquid reactivity: interplay of experimental and theoretical studies’ by Shengxin Chen et al., Catal. Sci. Technol., 2019, DOI: 10.1039/c9cy00953a.

scholarly journals Catalytic asymmetric C–Si bond activation via torsional strain-promoted Rh-catalyzed aryl-Narasaka acylation

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jia Feng ◽  
Xiufen Bi ◽  
Xiaoping Xue ◽  
Na Li ◽  
Lei Shi ◽  
...  
Keyword(s):  
Natural Products ◽  
Ring Opening ◽  
Kinetic Resolution ◽  
Bond Activation ◽  
Bond Cleavage ◽  
Catalytic Synthesis ◽  
Torsional Strain ◽  
Silanol Groups ◽  
Bioactive Natural Products ◽  
Ring Opening Reaction

Abstract Atropisomers are important organic frameworks in bioactive natural products, drugs as well as chiral catalysts. Meanwhile, silanols display unique properties compared to their alcohol analogs, however, the catalytic synthesis of atropisomers bearing silanol groups is challenging. Here, we show a rhodium-catalyzed torsional strain-promoted asymmetric ring-opening reaction for the synthesis of α-silyl biaryl atropisomers. The reaction features a dynamic kinetic resolution of C(Ar)-Si bond cleavage, whose stereochemistry was controlled by a phosphoramidite ligand derived from (S)-3-methyl-1-((2,4,6-triisopropylphenyl)sulfonyl)piperazine. This work is a demonstration of an aryl-Narasaka acylation, where the C(Ar)-Si bond cleavage is promoted by the torsional strain of α, α’-disubstituted silafluorene.

scholarly journals Mechanisms of Laser-Induced Reactions of Stacked Benzene Molecules: A Semiclassical Dynamics Simulation and CASSCF Calculation

2014 ◽  
Vol 2014 ◽  
pp. 1-11
Author(s):  
Kunxian Shu ◽  
Jie Zhao ◽  
Shuai Yuan ◽  
Yusheng Dou ◽  
Glenn V. Lo
Keyword(s):  
Ground State ◽  
Bond Cleavage ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Dynamics Simulation ◽  
Covalent Bonds ◽  
Semiclassical Dynamics ◽  
Ultrashort Laser ◽  
Electronic Ground ◽  
Casscf Calculation

The response to ultrashort laser pulses of two stacked benzene molecules has been studied by semiclassical dynamics simulation; two typical pathways were found following excitation of one of the benzene molecules by a 25 fs (FWHM), 4.7 eV photon. With a fluence of 40.49 J/m2, the stacked molecules form a cyclobutane benzene dimer; the formation of the two covalent bonds linking two benzenes occurs asynchronously after the excimer decays to electronic ground state. With a fluence of 43.26 J/m2, only one bond is formed, which breaks about 50 fs after formation, followed by separation into the two molecules. The deformation of benzene ring is found to play an important role in the bond cleavage.

Epoxide ring-opening reaction promoted by ionic liquid reactivity: interplay of experimental and theoretical studies

2019 ◽  
Vol 9 (20) ◽  
pp. 5567-5571 ◽  
Author(s):  
Shengxin Chen ◽  
Guixiang Zeng ◽  
Yingwei Li ◽  
Bin He ◽  
Ruixia Liu ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Propylene Oxide ◽  
Chemical Stability ◽  
Ring Opening ◽  
Epoxide Ring ◽  
Theoretical Studies ◽  
Epoxide Ring Opening ◽  
Ring Opening Reaction ◽  
Experimental And Theoretical Studies

Ionic liquids (ILs) have been widely introduced recently into the epoxide ring-opening reaction as catalysts or solvent without considering the chemical stability of ILs in propylene oxide (PO).

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