Введение
Добавление протона к атому, молекуле или иону, образуя конъюгированную кислоту. В химии протонизация (или гидронизация) – это присоединение протона (или гидрона, или иона водорода), обычно обозначаемого H⁺, к атому, молекуле или иону, в результате чего образуется конъюгированная кислота. (Обратный процесс, при котором протон удаляется из кислоты Брёнстеда-Лоури, называется депротонированием.) Примеры включают:
In chemistry, protonation (or hydronation) is the adding of a proton (or hydron, or hydrogen cation), usually denoted by H+, to an atom, molecule, or ion, forming a conjugate acid. (The complementary process, when a proton is removed from a Brønsted–Lowry acid, is deprotonation.) Some examples include
The protonation of water by sulfuric acid:
H2SO4 + H2O H3O+ + HSO4
The protonation of isobutene in the formation of a carbocation:
(CH3)2C=CH2 + HBF4 (CH3)3C+ + BF4
The protonation of ammonia in the formation of ammonium chloride from ammonia and hydrogen chloride:
NH3(g) + HCl(g) → NH4Cl(s)
Protonation is a fundamental chemical reaction and is a step in many stoichiometric and catalytic processes. Some ions and molecules can undergo more than one protonation and are labeled polybasic, which is true of many biological macromolecules. Protonation and deprotonation (removal of a proton) occur in most acid–base reactions; they are the core of most acid–base reaction theories. A Brønsted–Lowry acid is defined as a chemical substance that protonates another substance. Upon protonating a substrate, the mass and the charge of the species each increase by one unit, making it an essential step in certain analytical procedures such as electrospray mass spectrometry. Protonating or deprotonating a molecule or ion can change many other chemical properties, not just the charge and mass, for example solubility, hydrophilicity, reduction potential or oxidation potential, and optical properties can change.
Протонирование воды серной кислотой:
H₂SO₄ + H₂O H₃O⁺ + HSO₄⁻
In chemistry, protonation (or hydronation) is the adding of a proton (or hydron, or hydrogen cation), usually denoted by H+, to an atom, molecule, or ion, forming a conjugate acid. (The complementary process, when a proton is removed from a Brønsted–Lowry acid, is deprotonation.) Some examples include
The protonation of water by sulfuric acid:
H2SO4 + H2O H3O+ + HSO4
The protonation of isobutene in the formation of a carbocation:
(CH3)2C=CH2 + HBF4 (CH3)3C+ + BF4
The protonation of ammonia in the formation of ammonium chloride from ammonia and hydrogen chloride:
NH3(g) + HCl(g) → NH4Cl(s)
Protonation is a fundamental chemical reaction and is a step in many stoichiometric and catalytic processes. Some ions and molecules can undergo more than one protonation and are labeled polybasic, which is true of many biological macromolecules. Protonation and deprotonation (removal of a proton) occur in most acid–base reactions; they are the core of most acid–base reaction theories. A Brønsted–Lowry acid is defined as a chemical substance that protonates another substance. Upon protonating a substrate, the mass and the charge of the species each increase by one unit, making it an essential step in certain analytical procedures such as electrospray mass spectrometry. Protonating or deprotonating a molecule or ion can change many other chemical properties, not just the charge and mass, for example solubility, hydrophilicity, reduction potential or oxidation potential, and optical properties can change.
Протонирование изобутена при образовании карбокатиона:
(CH₃)₂C=CH₂ + HBF₄ (CH₃)₃C⁺ + BF₄⁻
In chemistry, protonation (or hydronation) is the adding of a proton (or hydron, or hydrogen cation), usually denoted by H+, to an atom, molecule, or ion, forming a conjugate acid. (The complementary process, when a proton is removed from a Brønsted–Lowry acid, is deprotonation.) Some examples include
The protonation of water by sulfuric acid:
H2SO4 + H2O H3O+ + HSO4
The protonation of isobutene in the formation of a carbocation:
(CH3)2C=CH2 + HBF4 (CH3)3C+ + BF4
The protonation of ammonia in the formation of ammonium chloride from ammonia and hydrogen chloride:
NH3(g) + HCl(g) → NH4Cl(s)
Protonation is a fundamental chemical reaction and is a step in many stoichiometric and catalytic processes. Some ions and molecules can undergo more than one protonation and are labeled polybasic, which is true of many biological macromolecules. Protonation and deprotonation (removal of a proton) occur in most acid–base reactions; they are the core of most acid–base reaction theories. A Brønsted–Lowry acid is defined as a chemical substance that protonates another substance. Upon protonating a substrate, the mass and the charge of the species each increase by one unit, making it an essential step in certain analytical procedures such as electrospray mass spectrometry. Protonating or deprotonating a molecule or ion can change many other chemical properties, not just the charge and mass, for example solubility, hydrophilicity, reduction potential or oxidation potential, and optical properties can change.
Протонирование аммиака при образовании хлорида аммония из аммиака и хлороводорода:
NH₃(г) + HCl(г) → NH₄Cl(т)
In chemistry, protonation (or hydronation) is the adding of a proton (or hydron, or hydrogen cation), usually denoted by H+, to an atom, molecule, or ion, forming a conjugate acid. (The complementary process, when a proton is removed from a Brønsted–Lowry acid, is deprotonation.) Some examples include
The protonation of water by sulfuric acid:
H2SO4 + H2O H3O+ + HSO4
The protonation of isobutene in the formation of a carbocation:
(CH3)2C=CH2 + HBF4 (CH3)3C+ + BF4
The protonation of ammonia in the formation of ammonium chloride from ammonia and hydrogen chloride:
NH3(g) + HCl(g) → NH4Cl(s)
Protonation is a fundamental chemical reaction and is a step in many stoichiometric and catalytic processes. Some ions and molecules can undergo more than one protonation and are labeled polybasic, which is true of many biological macromolecules. Protonation and deprotonation (removal of a proton) occur in most acid–base reactions; they are the core of most acid–base reaction theories. A Brønsted–Lowry acid is defined as a chemical substance that protonates another substance. Upon protonating a substrate, the mass and the charge of the species each increase by one unit, making it an essential step in certain analytical procedures such as electrospray mass spectrometry. Protonating or deprotonating a molecule or ion can change many other chemical properties, not just the charge and mass, for example solubility, hydrophilicity, reduction potential or oxidation potential, and optical properties can change.
Протонизация – фундаментальная химическая реакция, являющаяся стадией многих стехиометрических и каталитических процессов. Некоторые ионы и молекулы могут подвергаться множественному протонированию и называются полибазисными, что характерно для многих биологических макромолекул. Протонизация и депротонизация (удаление протона) происходят в большинстве кислотно-основных реакций и лежат в основе большинства теорий кислотно-основных реакций. Кислота Брёнстеда-Лоури определяется как химическое вещество, способное протонировать другое вещество. При протонировании субстрата масса и заряд образующегося вида увеличиваются на единицу, что делает этот процесс важным этапом в некоторых аналитических процедурах, таких как электрораспылительная масс-спектрометрия. Протонирование или депротонирование молекулы или иона может изменять не только заряд и массу, но и другие химические свойства, например, растворимость, гидрофильность, окислительно-восстановительный потенциал и оптические свойства.
In chemistry, protonation (or hydronation) is the adding of a proton (or hydron, or hydrogen cation), usually denoted by H+, to an atom, molecule, or ion, forming a conjugate acid. (The complementary process, when a proton is removed from a Brønsted–Lowry acid, is deprotonation.) Some examples include
The protonation of water by sulfuric acid:
H2SO4 + H2O H3O+ + HSO4
The protonation of isobutene in the formation of a carbocation:
(CH3)2C=CH2 + HBF4 (CH3)3C+ + BF4
The protonation of ammonia in the formation of ammonium chloride from ammonia and hydrogen chloride:
NH3(g) + HCl(g) → NH4Cl(s)
Protonation is a fundamental chemical reaction and is a step in many stoichiometric and catalytic processes. Some ions and molecules can undergo more than one protonation and are labeled polybasic, which is true of many biological macromolecules. Protonation and deprotonation (removal of a proton) occur in most acid–base reactions; they are the core of most acid–base reaction theories. A Brønsted–Lowry acid is defined as a chemical substance that protonates another substance. Upon protonating a substrate, the mass and the charge of the species each increase by one unit, making it an essential step in certain analytical procedures such as electrospray mass spectrometry. Protonating or deprotonating a molecule or ion can change many other chemical properties, not just the charge and mass, for example solubility, hydrophilicity, reduction potential or oxidation potential, and optical properties can change.
Ставки
Протонирование часто протекает быстро, отчасти из-за высокой подвижности протонов во многих растворителях. Скорость протонирования связана с кислотностью протонирующего агента: протонирование слабыми кислотами происходит медленнее, чем протонирование того же основания сильными кислотами. Скорости протонирования и депротонирования могут быть особенно низкими, если протонирование вызывает значительные структурные изменения.
Восстановительная способность и катализатор
Протонация обычно обратима, и структура и связи сопряженного основания обычно не изменяются при протонировании. Однако в некоторых случаях протонирование вызывает изомеризацию, например, цис-алкены могут превращаться в транс-алкены при использовании каталитического количества протонирующего агента. Многие ферменты, такие как серингидролазы, функционируют посредством механизмов, включающих обратимое протонирование субстратов.