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Hyperconjugation can be used to rationalize a variety of chemical phenomena, including the anomeric effect, the gauche effect, the rotational barrier of ethane, the beta-silicon effect, the vibrational frequency of exocyclic carbonyl groups, and the relative stability of substituted carbocations and substituted carbon centred radicals, and the thermodynamic Zaitsev's rule for alkene stability.
Hydrogen–deuterium exchange (also called H–D or H/D exchange) is a chemical reaction in which a covalently bonded hydrogen atom is replaced by a deuterium atom, or vice versa. It can be applied most easily to exchangeable protons and deuterons, where such a transformation occurs in the presence of a suitable deuterium source, without any ...
Exchange interaction is the main physical effect responsible for ferromagnetism, and has no classical analogue. For bosons, the exchange symmetry makes them bunch together, and the exchange interaction takes the form of an effective attraction that causes identical particles to be found closer together, as in Bose–Einstein condensation.
A primary kinetic isotope effect (PKIE) may be found when a bond to the isotopically labeled atom is being formed or broken. [3] [4]: 427 Depending on the way a KIE is probed (parallel measurement of rates vs. intermolecular competition vs. intramolecular competition), the observation of a PKIE is indicative of breaking/forming a bond to the isotope at the rate-limiting step, or subsequent ...
Negative hyperconjugation is a theorized phenomenon in organosilicon compounds, in which hyperconjugation stabilizes or destabilizes certain accumulations of positive charge. The phenomenon explains corresponding peculiarities in the stereochemistry and rate of hydrolysis .
The following table shows a series of Gibbs free energy of binding between benzene and several cations in the gas phase. [ 2 ] [ 6 ] For a singly charged species, the gas-phase interaction energy correlates with the ionic radius , r i o n {\displaystyle r_{\mathrm {ion} }} (non-spherical ionic radii are approximate).
Gas exchange is the physical process by which gases move passively by diffusion across a surface. For example, this surface might be the air/water interface of a water body, the surface of a gas bubble in a liquid, a gas-permeable membrane, or a biological membrane that forms the boundary between an organism and its extracellular environment.
The Cieplak effect relies on the stabilizing interaction of mixing full and empty orbitals to delocalize electrons, known as hyperconjugation. [2] When the highest occupied molecular orbital of one system and the lowest unoccupied molecular orbital of another system have comparable energies and spatial overlap, the electrons can delocalize and sink into a lower energy level.