Video Experimental Relacionado

Updated: May 24, 2025

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O

Published on: October 7, 2020

Reducción selectiva gradual de nitrato y nitrito a nitrógeno o amoníaco

Jewelianna M Moore¹, Tabitha J Miller², Manting Mu³

¹Department of Chemistry, Texas A&M University, 580 Ross St., College Station, Texas 77843, United States.

Journal of the American Chemical Society

|February 28, 2025

Resumen

Los investigadores desarrollaron un método para convertir nitrato (NO3) y nitrito (NO2) en gas nitrógeno (N2) o amoníaco (NH3). Este estudio ofrece información sobre los mecanismos de reducción de oxyaniones de nitrógeno.

Área de la Ciencia:

Química inorgánica
Catálisis
Química biomimética

Sus antecedentes:

La reducción de nitratos y nitritos es un proceso biogeoquímico crucial.
Trabajos anteriores en nuestro laboratorio lograron la reducción de nitratos a óxido nítrico (NO) utilizando un complejo de hierro específico.
Comprender estas vías de reducción es vital para la investigación del ciclo del nitrógeno.

Objetivo del estudio:

Desarrollar un método para la reducción selectiva de nitrato (NO3) y nitrito (NO2) a gas nitrógeno (N2) o amoníaco (NH3).
Elucidar los mecanismos escalonados de la reducción de oxyaniones de nitrógeno.
Imitar los procesos enzimáticos naturales para la transformación de compuestos de nitrógeno.

Principales métodos:

Utilizó el complejo [N{\\displaystyle \\mathbb {N} }₃Fe]OTf₂ para las reacciones de reducción selectiva.
Se han investigado dos vías: la reducción de nitrito a N₂ a través de intermediarios NO y N₂O, y la reducción de un complejo NO unido a NH₃.
Utilizó ¹⁵N estudios de etiquetado para la confirmación de fuentes de nitrógeno y estudios computacionales para apoyar los intermediarios propuestos como la hidroxilamina (NH₂OH).

Principales resultados:

Se ha demostrado con éxito la reducción de nitrito (NO₂-) a nitrógeno gaseoso (N₂) mediante un proceso en varios pasos en el que participan trifenilfosfina (PPh₃) y el complejo de hierro.
Se ha obtenido un rendimiento modesto del 29% para la reducción del complejo NO unido al amoníaco (NH₃) utilizando reductores químicos.
Se ha identificado la hidroxilamina (NH₂OH) como un intermediario plausible en la reducción del NO enlazado.

Conclusiones:

El estudio presenta un nuevo método para la reducción selectiva de nitrato y nitrito a N₂ o NH₃.
Los hallazgos proporcionan información valiosa sobre los mecanismos graduales de reducción de oxyaniones de nitrógeno, trazando paralelos con las vías enzimáticas naturales.
Este trabajo contribuye a la comprensión del ciclo del nitrógeno y al desarrollo de catalizadores sintéticos para las transformaciones de compuestos de nitrógeno.

Más Videos Relacionados

Automated, High-resolution Mobile Collection System for the Nitrogen Isotopic Analysis of NOx

Automated, High-resolution Mobile Collection System for the Nitrogen Isotopic Analysis of NOx

Published on: December 20, 2016

Measuring Nitrite and Nitrate, Metabolites in the Nitric Oxide Pathway, in Biological Materials using the Chemiluminescence Method

Measuring Nitrite and Nitrate, Metabolites in the Nitric Oxide Pathway, in Biological Materials using the Chemiluminescence Method

Published on: December 25, 2016

Videos de Conceptos Relacionados

Preparation of Amines: Reduction of Oximes and Nitro Compounds

Preparation of Amines: Reduction of Oximes and Nitro Compounds

Oximes can be reduced to primary amines using catalytic hydrogenation, hydride reduction, or sodium metal reduction. The reduction of aliphatic and aromatic nitro compounds to primary amines takes place by either catalytic hydrogenation or by using active metals like Fe, Zn, and Sn in the presence of an acid.
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...

Overview of Nitrogen Metabolism

Overview of Nitrogen Metabolism

Nitrogen is a very important element for life because it is a major constituent of proteins and nucleic acids. It is a macronutrient, and in nature, it is recycled from organic compounds and stored in the form of ammonia, ammonium ions, nitrate, nitrite, or nitrogen gas by many metabolic processes. Many of these metabolic processes are carried out only by prokaryotes.
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this...

2° Amines to N-Nitrosamines: Reaction with NaNO2

2° Amines to N-Nitrosamines: Reaction with NaNO₂

Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.

Preparation of Amines: Reduction of Amides and Nitriles

Preparation of Amines: Reduction of Amides and Nitriles

Nitriles can be reduced to primary amines using reducing agents like lithium aluminum hydride or catalytic hydrogenation. The reduction introduces an amino group with an extra carbon in the skeleton. Nitriles are formed from the reaction between alkyl halides and sodium cyanide through the SN2 mechanism. Primary alkyl halides are the preferred substrates to prepare nitriles.
Amides can be reduced to primary, secondary, and tertiary amines using catalytic hydrogenation, active metals like Fe,...

1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism

1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO₂ Mechanism

Nitrous acid is a relatively weak and unstable acid prepared in situ by the reaction of sodium nitrite and cold, dilute hydrochloric acid. In an acidic solution, the nitrous acid undergoes protonation when it loses water to form a nitrosonium ion—an electrophile. Nitrous acid reacts with primary amines to give diazonium salts. The reaction is called diazotization of primary amines.

Preparation of Amines: Reductive Amination of Aldehydes and Ketones

Preparation of Amines: Reductive Amination of Aldehydes and Ketones

Carbonyl compounds and primary amines undergo reductive amination first to produce imines, followed by secondary amines in the same reaction mixture, using selective reducing agents like sodium cyanoborohydride or sodium triacetoxyborohydride. Reductive amination produces different degrees of substitution of amines depending on the starting amine substrate.