用激素进行原子抽象的绝对率计算:能量,结构和电子因素
Luis G Arnaut1, Alberto A C C Pais, Sebastião J Formosinho
1Universidade de Coimbra, Departamento de Química, P-3049 Coimbra Codex, Portugal. lgarnaut@ci.uc.pt
Journal of the American Chemical Society
|April 24, 2003
概括
这项研究引入了一种新的计算模型,用于预测没有可调节参数的原子转移反应速率. 该模型准确计算过渡状态能量和反应速率,有助于理解化学反应性.
科学领域:
- 物理化学 物理化学
- 理论化学 理论化学
- 化学动力学 化学动力学
背景情况:
- 原子转移反应是化学的基础.
- 准确预测反应速率对于理解化学过程至关重要.
- 现有的模型通常依赖于可调节的参数,限制了它们的预测能力.
研究的目的:
- 开发一个无参数的计算模型来计算过渡状态能量和反应速率.
- 为了发现化学反应的新模式.
- 为了对模型与原子转移的实验数据进行验证.
主要方法:
- 从反应能量,电友性指数,键长度和振动频率计算过渡状态能量.
- 在过渡状态理论中使用交叉状态模型与半经典道校正 (ISM/scTST).
- 将计算的振动附带电阻与实验激活能量进行比较.
主要成果:
- 该模型成功地预测了没有可调节参数的过渡状态能量.
- 计算的反应速率是在室温实验值的数量级之内.
- 温度依赖性和动态同位素效应与实验数据有很好的一致性.
结论:
- 开发的模型准确地阐明了反应能量,电友性,结构参数和反应活性中的道化作用.
- 该模型为新的原子转移反应的定量预测提供了一个强大的工具.
- 这种方法推进了化学反应动态的理论理解和预测.
相关概念视频
Atomic Structure
All matter is composed of atoms, the smallest individual units of elements. Each atom is made up of three subatomic particles: protons, neutrons, and electrons. Together, these three particles account for the mass and the charge of an atom.The History of Atomic TheoryThe first person to propose that everything on Earth is made up of tiny particles was the Greek philosopher Democritus, around 450 B.C. He used the term atomos, Greek for “indivisible,” from which the modern term “atom” is derived.
Electron Behavior
Electrons are negatively charged subatomic particles that are attracted to an orbit around the positively-charged nucleus of an atom. They reside in locations that are associated with energy levels called shells and are further organized into sub-shells and orbitals within each shell.Electrons Orbit the NucleusElectrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the nucleus...
Subatomic Particles
Dalton was only partially correct about the particles that make up matter. All matter is composed of atoms, and atoms are composed of three smaller subatomic particles: protons, neutrons, and electrons. These three particles account for the mass and the charge of an atom.
Electronic Structure of Atoms
An atom comprises protons and neutrons, which are contained inside the dense, central core called the nucleus, with electrons present around the nucleus. Taking into account the wave–particle duality of electrons and the uncertainty in position around the nucleus, quantum mechanics provides a more accurate model for the atomic structure. It describes atomic orbitals as the regions around the nucleus where electrons of discrete energy exist, characterized by four quantum numbers: n, l, ml, and...
Atomic Structure
The Greek philosopher Democritus proposed that everything on Earth is made up of tiny particles called atomos, Greek for "indivisible," from which the modern term "atom" is derived. In the 19th century, John Dalton proposed the atomic theory that is still largely correct today. He put forth five postulates to explain how atoms made up the world around us. (1) All matter is composed of infinitely small particles or atoms. (2) All atoms of a given element are identical to one another and (3) are...
Electron Behavior
Electrons are negatively charged subatomic particles attracted to and orbit around the positively-charged nucleus of an atom. They reside in spaces associated with energy levels called shells and are further organized into subshells and orbitals within each shell.
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the nucleus have less energy,...
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the nucleus have less energy,...


