在充电水集群中对键的几何H/D同位素效应
Masanori Tachikawa1, Motoyuki Shiga
1Quantum Chemical Physics Division, Graduate School of Science, Yokohama-City University, Japan. tachi@yokohama-cu.ac.jp
Journal of the American Chemical Society
|August 25, 2005
概括
杜特伦替代缩短了H5O2+中的氧气分离,但在H3O2-中延长了它. 这个量子力学同位素效应取决于键.
科学领域:
- 物理化学 物理化学
- 计算化学计算化学
- 量子力学就是量子力学.
背景情况:
- 像H5O2+和H3O2这样的水复合体在化学和生物系统中起着至关重要的作用.
- 了解键动态对于解释分子行为至关重要.
研究的目的:
- 为了研究带电水复合体中质子/质子子替代的几何同位素效应.
- 阐明量子效应对H5O2+和H3O2中的键的影响.
主要方法:
- 使用了精确的初始路径积分模拟.
- 电子相关性效应被明确考虑.
主要成果:
- 杜特伦替代导致H5O2+中较短的氧-氧分离.
- 相反,氨酸替代导致H3O2-. .中的氧氧分离时间更长.
- 观察到的同位素效应在正负电荷物种之间有所不同.
结论:
- 几何同位素效应对水复合体的电荷状态敏感.
- 由单或双井电位影响的键上的量子效应决定了观察到的行为.
相关概念视频
00:26Hydrogen Bonds
Hydrogen BondsHydrogen bonds are weak attractions between atoms that have formed other chemical bonds. One of these atoms is electronegative, like oxygen, and has a partial negative charge. The other is a hydrogen atom that has bonded with another electronegative atom and has a partial positive charge.Hydrogen Bonds Control the World!Because hydrogen has very weak electronegativity when it binds with a strongly electronegative atom, such as oxygen or nitrogen, electrons in the bond are...
04:01VSEPR Theory and the Effect of Lone Pairs
Effect of Lone Pairs of Electrons on Molecule Geometry
03:24Hybridization of Atomic Orbitals I
The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. The new orbitals that...
00:48¹H NMR of Labile Protons: Deuterium (²H) Substitution
This lesson illustrates the role of deuterium substitution in simplifying the NMR spectrum of compounds comprising labile protons. One method employed is the use of deuterium. Amongst the three isotopes of hydrogen, deuterium (2H) has a nucleus composed of one proton and one neutron. When the D2O solvent is added to a pure dry ethanol solution, its labile proton is substituted with deuterium.
01:01Introduction to Chemical Bonds
Chemical Bonds
The electrons of the outermost energy level determine the energetic stability of the atom and its tendency to form chemical bonds with other atoms. The innermost electron shell has a maximum capacity of two electrons, but the next two electron shells can each have a maximum of eight electrons. This is known as the octet rule, which states that, with the exception of the innermost shell, atoms are most stable energetically when they have eight electrons in their valence shell, the...
The electrons of the outermost energy level determine the energetic stability of the atom and its tendency to form chemical bonds with other atoms. The innermost electron shell has a maximum capacity of two electrons, but the next two electron shells can each have a maximum of eight electrons. This is known as the octet rule, which states that, with the exception of the innermost shell, atoms are most stable energetically when they have eight electrons in their valence shell, the...
01:04Hydrogen Bonds
A hydrogen bond is formed when a weakly positive hydrogen atom already bonded to one electronegative atom (for example, the oxygen in the water molecule) is attracted to another electronegative atom from another polar molecule, such as water (H2O), hydrogen fluoride (HF), or ammonia (NH3). The huge electronegativity difference between the H atom (2.1) and the atom to which it is bonded (4.0 for an F atom, 3.5 for an O atom, or 3.0 for an N atom), combined with the very small size of an H atom...