protonation


Also found in: Dictionary, Wikipedia.

protonation

(prō`tənā'shən), in chemistry, addition of a protonproton,
elementary particle having a single positive electrical charge and constituting the nucleus of the ordinary hydrogen atom. The positive charge of the nucleus of any atom is due to its protons.
..... Click the link for more information.
 to an atom, molecule, or ion. The proton is the nucleus of the hydrogenhydrogen
[Gr.,=water forming], gaseous chemical element; symbol H; at. no. 1; interval in which at. wt. ranges 1.00784–1.00811; m.p. −259.14°C;; b.p. −252.87°C;; density 0.08988 grams per liter at STP; valence usually +1.
..... Click the link for more information.
 atom; the positive hydrogen ion, H+, consists of a single proton. An example of protonation is the formation of the ammonium groupammonium group,
in chemistry, a positively charged nitrogen atom joined by single bonds to four other atoms or groups. The simplest ammonium group, NH4+, is formed by protonation of ammonia, NH3, e.g.
..... Click the link for more information.
 NH4+ from ammonia, NH3. Protonation often occurs in the reaction of an acid with a base to form a salt (see acids and basesacids and bases,
two related classes of chemicals; the members of each class have a number of common properties when dissolved in a solvent, usually water. Properties
..... Click the link for more information.
; saltssalt,
chemical compound (other than water) formed by a chemical reaction between an acid and a base (see acids and bases). Characteristics and Classification of Salts

The most familiar salt is sodium chloride, the principal component of common table salt.
..... Click the link for more information.
). Protonation differs from hydrogenationhydrogenation
, chemical reaction of a substance with molecular hydrogen, usually in the presence of a catalyst. A common hydrogenation is the hardening of animal fats or vegetable oils to make them solid at room temperature and improve their stability.
..... Click the link for more information.
 in that during protonation a change in charge of the protonated species occurs, whereas the charge is unaffected during hydrogenation.
References in periodicals archive ?
At lower pH, the amounts of these groups were lower because of protonation of the carboxylic groups.
Kovalevsky and his colleagues are interested in protonation because they need to know how protons move during catalysis.
The decline in pH observed under permanent fallow and annual cropping reduced the effective CEC of the soil through protonation of weakly acidic functional groups such as carboxyl groups in SOM (Thomas and Hargrove 1984).
Following determination of the protonation states of the ionizable amino acids using the PDB2PQR server (Dolinsky et al.
The acidity of solution is an important parameter for the sorption of heavy metals from aqueous solutions since the value of pH is responsible for protonation of metal binding sites, calcium carbonate solubility and [Cu.
Due to protonation, it is commonly positively charged in water with different resonance forms.
Vitamin C is found as the L-ascorbate enantiomer (the cleproton-ated form) in biological systems, as a pH5, or less, is necessary for protonation to form the acid.
These ranges of pHs had been chosen due to their influences on hydrolysis reaction, condensation of silane with itself and with the particle, as well as to their effects on protonation of amino functional groups of silane molecules used.
With increasing the pH of SSAS, the degree of protonation of the RH surface reduces gradually and hence adsorption is decreased [30].
Protonation sites and dissociation mechanisms of t-butylcarbamates in tandem mass spectrometric assays for newborn screening.
This problem is even more significant in the case of peptides and proteins; they contain multiple basic nitrogen atoms within the molecule, each of which is susceptible to protonation and association.
It is worth noting that magnetite is an amphoteric solid, which can develop charges in the protonation and deprotonation reactions of Fe-OH surface sites (Hadju et al.