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The molecule adopts a structure similar to that of ethane, with which it is isoelectronic. The B−N distance is 1.58(2) Å. The B−H and N−H distances are 1.15 and 0.96 Å, respectively. Its similarity to ethane is tenuous since ammonia borane is a solid and ethane is a gas: their melting points differing by 284 °C.
They undergo rapid halide exchange reactions: BF 3 + BCl 3 → BF 2 Cl + BCl 2 F. Because of the facility of this exchange process, the mixed halides cannot be obtained in pure form. Boron trifluoride is a versatile Lewis acid that forms adducts with such Lewis bases as fluoride and ethers: CsF + BF 3 → Cs[BF 4] O(CH 2 CH 3) 2 + BF 3 → BF 3 ...
A single-displacement reaction, also known as single replacement reaction or exchange reaction, is an archaic concept in chemistry. It describes the stoichiometry of some chemical reactions in which one element or ligand is replaced by an atom or group. [1] [2] [3] It can be represented generically as:
Adsorption is the process by which a gas (or solution) phase molecule (the adsorbate) binds to solid (or liquid) surface atoms (the adsorbent). The reverse of adsorption is desorption, the adsorbate splitting from adsorbent. In a reaction facilitated by heterogeneous catalysis, the catalyst is the adsorbent and the reactants are the adsorbate.
Crossover experiments allow for experimental study of a reaction mechanism. Mechanistic studies are of interest to theoretical and experimental chemists for a variety of reasons including prediction of stereochemical outcomes, optimization of reaction conditions for rate and selectivity, and design of improved catalysts for better turnover number, robustness, etc. [6] [7] Since a mechanism ...
Gas phase ion chemistry is a field of science encompassed within both chemistry and physics. It is the science that studies ions and molecules in the gas phase, most often enabled by some form of mass spectrometry. By far the most important applications for this science is in studying the thermodynamics and kinetics of reactions.
Figure 6:Reaction Coordinate Diagrams showing reactions with 0, 1 and 2 intermediates: The double-headed arrow shows the first, second and third step in each reaction coordinate diagram. In all three of these reactions the first step is the slow step because the activation energy from the reactants to the transition state is the highest.
To use FMO theory, the reaction should be considered as two separate ideas: (1) whether or not the reaction is allowed, and (2) which mechanism the reaction proceeds through. In the case of a [1,5] shift on pentadiene, the HOMO of the sigma bond (i.e., a constructive bond) and the LUMO of butadiene on the remaining 4 carbons is observed.