protonation


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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.
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 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.
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 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.
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 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
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; 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.
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). 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.
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 in that during protonation a change in charge of the protonated species occurs, whereas the charge is unaffected during hydrogenation.
References in periodicals archive ?
The electrostatic interaction between dye molecules and adsorbent was decreased, representing increase in the degree of dissociation of MGO by facilitating the protonation process [43, 44].
It opened our eyes to how changes in temperature and pH can impact the protonation state of the drug, which in turn makes it more or less effective.
The protonation and deprotonation and various other physico-chemical properties of PANI can be traced to the presence of the--NH--group [3].
Raising the pH can be attributed to protonation of the amino groups present in bacteria [5,39] and also due to the decomposition of thiosulfate [40].
According to Osterholtz and Pohl, the mechanism for acid-catalyzed hydrolysis is a rapid equilibrium protonation of the substrate, followed by a bimolecular [S.
The water molecules were removed and 3D protonation of the receptor molecules was carried out.
At pH values higher than pHopt, the extraction efficiency reduces most likely due to a decrease of degree of HAs protonation.
At lower pH, the amounts of these groups were lower because of protonation of the carboxylic groups.
Presuming protonation of the neutral ester or neutral species of the bis-p-MPPE, the bend obtained by rates constants against detergent concentration was through due to the result of the maximum protonation which is common in amide system (Bunton and Moffatt, 1986).
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.
Among the topics are the time evolution of the hard and soft acids and bases theory, a fast solver for the backward heat conduction problem in unbounded domains, classical charged particles in arbitrary motion, a second-order linear differential equation in its exact form, and evaluating protonation energy of molecules in terms of quantum theoretical descriptors.