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If the correction factor is greater than one, the reaction displays an asymmetric amplification, also known as a positive non-linear effect. Under the ML 2 model, a (+)-NLE infers a less reactive heterochiral catalyst. In this case, the equilibrium constant K also increases as the correction factor increases.
Matrix isolation is an experimental technique used in chemistry and physics. It generally involves a material being trapped within an unreactive matrix. A host matrix is a continuous solid phase in which guest particles (atoms, molecules, ions, etc.) are embedded. The guest is said to be isolated within the host matrix.
In cooperativity, the initial ligand binding affects the host's affinity for subsequent ligands. In positive cooperativity, the first binding event enhances the affinity of the host for another ligand. Examples of positive and negative cooperativity are hemoglobin and aspartate receptor, respectively. [10] General Host–Guest Binding. (1.)
In some cases, true host-guest reversibility is observed, in other cases, the encapsulated guest cannot escape. [13] Molecular encapsulation of a nitrobenzene bound within a hemicarcerand. [14] An important implication of encapsulation (and host-guest chemistry in general) is that the guest behaves differently from the way it would when in ...
Static molecular recognition is likened to the interaction between a key and a keyhole; it is a 1:1 type complexation reaction between a host molecule and a guest molecule to form a host–guest complex. To achieve advanced static molecular recognition, it is necessary to make recognition sites that are specific for guest molecules.
In organic chemistry, kinetic resolution is a means of differentiating two enantiomers in a racemic mixture.In kinetic resolution, two enantiomers react with different reaction rates in a chemical reaction with a chiral catalyst or reagent, resulting in an enantioenriched sample of the less reactive enantiomer. [1]
Integration host factor, IHF, is not a nucleoid-associated protein only found in gram negative bacteria. [15] It is a 20 kDa heterodimer, composed of α and β subunits that bind to the sequence 5' - WATCAANNNNTTR - 3' and bends the DNA approximately 160 degrees. [16] The β arms of IHF have Proline residues that help stabilize the DNA kinks.
In 1962, Edwards and Pearson (the latter of HSAB theory) introduced the phrase alpha effect for this anomaly. He offered the suggestion that the effect was caused by a transition state (TS) stabilization effect: on entering the TS the free electron pair on the nucleophile moves away from the nucleus, causing a partial positive charge which can be stabilized by an adjacent lone pair as for ...