The formation of the aromatic ring during the formation of polycyclic aromatic hydrocarbons (PAHs) remains controversial and the experimental evidence is still lacking. Moreover, the formation mechanism of benzene fro...The formation of the aromatic ring during the formation of polycyclic aromatic hydrocarbons (PAHs) remains controversial and the experimental evidence is still lacking. Moreover, the formation mechanism of benzene from acetylene in the gas phase has also puzzled organic chemists for decades. Here, ab initio molecular dynamics simulations and electronic structure calculations provide compelling evidence for an unexpected competitive reaction pathway in which the aromatic ring is formed through successive additions of vinylidene. Moreover, no collisions cause bond dissociation of the acetylene molecule during the formation of benzene in this work. This study reveals the key role for the vinylidene carbene and determines the lifetime of vinylidene.展开更多
The hydrated-proton structure is critical for understanding the proton transport in water.However,whether the hydrated proton adopts Zundel or Eigen structure in solution has been highly debated in the past several de...The hydrated-proton structure is critical for understanding the proton transport in water.However,whether the hydrated proton adopts Zundel or Eigen structure in solution has been highly debated in the past several decades.Current experimental techniques cannot directly visualize the dynamic structures in situ,while the available theoretical results on the infrared(IR)spectrum derived from current configurational models cannot fully reproduce the experimental results and thus are unable to provide their precise structures.In this work,using H5O2^+ as a model,we performed first-principles calculations to demonstrate that both the structural feature and the IR frequency of proton stretching,characteristics to discern the Zundel or Eigen structures,evolve discontinuously with the change of the O–O distance.A simple formula was introduced to discriminate the Zundel,Zundel-like,and Eigen-like structures.This work arouses new perspectives to understand the proton hydration in water.展开更多
基金supported by the National Natural Science Foundation of China(No.21403221 and No.91441106)
文摘The formation of the aromatic ring during the formation of polycyclic aromatic hydrocarbons (PAHs) remains controversial and the experimental evidence is still lacking. Moreover, the formation mechanism of benzene from acetylene in the gas phase has also puzzled organic chemists for decades. Here, ab initio molecular dynamics simulations and electronic structure calculations provide compelling evidence for an unexpected competitive reaction pathway in which the aromatic ring is formed through successive additions of vinylidene. Moreover, no collisions cause bond dissociation of the acetylene molecule during the formation of benzene in this work. This study reveals the key role for the vinylidene carbene and determines the lifetime of vinylidene.
基金the National Natural Science Foundation of China(Grant No.21773287).
文摘The hydrated-proton structure is critical for understanding the proton transport in water.However,whether the hydrated proton adopts Zundel or Eigen structure in solution has been highly debated in the past several decades.Current experimental techniques cannot directly visualize the dynamic structures in situ,while the available theoretical results on the infrared(IR)spectrum derived from current configurational models cannot fully reproduce the experimental results and thus are unable to provide their precise structures.In this work,using H5O2^+ as a model,we performed first-principles calculations to demonstrate that both the structural feature and the IR frequency of proton stretching,characteristics to discern the Zundel or Eigen structures,evolve discontinuously with the change of the O–O distance.A simple formula was introduced to discriminate the Zundel,Zundel-like,and Eigen-like structures.This work arouses new perspectives to understand the proton hydration in water.
