Search results for "AMMONIA"

Glutamine synthetase from roots of Brassica napus. Nucleotide sequence of a cytosolic isoform.

1994

A novel approach to polymer-template mesoporous molecular sieves

2000

A novel synthesis route was developed to produce spherical silica particles. The synthesis is based on a modified Stoeber method and the room-temperature synthesis of MCM 41S-materials applying tetraethoxysilane, alcohol, water, ammonia and homopolymers as template. The specific surface area, the specific pore volume and the average pore diameter were varied in the following ranges: 5 – 1,000 m2/g; 0.1 – 1.0 cm3/g and 2-50 nm. With respect to catalytic applications hetero-atoms e.g. Al were incorporated into the silica framework.

Partialsynthese neuer Ergolinderivate aus Clavinalkoloiden, 5. Mitt. N-1- und N-6-mono- und disubstituierte Festuclavine

1985

Festuclavin (1), 6-Cyano-6-nor-1 (3), 6-Nor-1 (5) und 6-Allyl-6-nor-1 (7) lassen sich in flussigem Ammoniak mit Kalium und dem entsprechenden Iodid in ihre 1-Allyl- und 1-Propyl-Derivate uberfuhren. Die Darstellung von 7 aus 5 wird beschrieben. Partial Syntheses of New Ergoline Derivatives from Clavine Alkaloids, V: Festuclavines Mono- and Disubstituted at N-1 and N-6 Festuclavine (1), 6-cyano-6-nor-1 (3), 6-nor-1 (5) and 6-allyl-6-nor-1 (7) were converted to their 1-allyl- and 1-propyl derivatives with potassium and the corresponding iodide in ammonia. The preparation of 7 from 5 is described.

Imidazolsynthesen, Mitt. Synthese α-substituierter 4(5)-Methoxymethyl-5(4)-methyl-imidazole

1977

Methoxymercurierung der α,β-ungesattigten Ketone 1 ergibt α-Acetoxymercuri-β-methoxy-ketone 2, die direkt zu α-Brom-β-methoxy-ketonen 3 bromo- demercuriert werden. Cyclisierung von 3 mit Formamidinacetat in flussigem Ammoniak fuhrt zu α-substituierten 4(5)-Methoxy-methyl-5(4)-methyl-imidazolen 4, deren Struktur 13C-NMR-spektroskopisch gesichert ist. Synthesis of α-Substituted 4(5)-Methoxymethyl-5(4)-methylimidazoles Methoxymercuration of the α,β-unsaturated ketones 1 produces the α-acetoxymercury-β-methoxyketones 2, which are bromo-demercurised without isolation to give the α-bromo-β-methoxyketones 3. Cyclisation of 3 with formamidine acetate in liquid ammonia leads to α-substituted 4(5)-me…

Über die polymerisation von acrylsäurechlorid

1960

Monomeres Acrylsaurechlorid wird mittels Azodiisobuttersaurenitril in Dioxan bei 50°C polymerisiert. Bei Ausschlus von Feuchtigkeit und Sauerstoff entstehen bis zu 90% Umsatz unvernetzte Polymere. Durch Reaktion mit flussigem Ammoniak wurden Polyacrylamide erhalten, die zur viskosimetrischen Molgewichtsbestimmung dienten. Monomeric acrylyl chloride was polymerized in dioxane at 50°C by azo-bis-isobutyronitrile. With the exclusion of moisture and oxygen, a non-cross-linked polymer with a 90% yield was obtained. Polyacrylamides were formed by the reaction of polyacrylyl chloride with liquid ammonia. These products were used for viscosimetric molecular weight determinations.

Eine neue Synthese von Imidazolderivaten. 1. Mitt.: Zur Darstellung 2-substituierter Imidazol-4-alkohole

1973

2-Substituierte Imidazol-4-alkohole (3) lassen sich aus Alkyl- oder Aryliminoestern (1) und α-Hydroxyketonen (2) in flussigem Ammoniak unter Druck mit guten Ausbeuten darstellen. A New Synthesis of Imidazole Derivatives The 2-substituted imidazole-4-alcohols (3) are obtained from alkyl- or aryl-iminoesters (1) and α-hydroxy-ketones (2) in liquid ammonia under pressure in good yields.

Photoreactivity of Iron-Doped Titanium Dioxide Powders for Dinitrogen Reduction to Ammonia

1989

The production of NH3 from N2 and H2O on Fe/TiO2 has been studied in a continuous photoreactor under UV radiation. An ESR study of the catalysts shows that Fe3+ ions are better electron traps than Ti4+ ions. This trapping can be irreversible if the corresponding holes originate stable species adsorbed on the catalyst surface. The charge separation, thus favoured by the Fe3+ ions, helps the N2 adsorption by its reaction with surface species activated by holes. The best activity is found when no excess Fe is segregated at the surface; overall turnover for N2 reduction as high as 6 e−/Fe atom can be reached before catalyst deactivation.

Umsetzung von amino-aziminen mit basen

1980

Abstract Amino-azimines of type (1) react at room temperature with bases (ammonia, aliphatic amines, hydrazine and methyl-hydrazine, aqueous/ethanolic sodium hydroxide) by cleavage of the to the and the NNN moieties (azide).

Der einfluß benachbarter grundbausteine auf die ammonolyse von essigsäureestern phenolischer mehrkernverbindungen

1972

Die Ammonolyse der Essigsaureester verschiedener phenolischer Zwei- und Dreikernverbindungen, die neben Methylphenolbausteinen jeweils einen Nitrophenolbaustein enthalten, wurde untersucht. In allen Fallen wird wie bei einkernigen Nitrophenylestern die Esterbindung im Nitrophenolbaustein ammonolytisch gespalten. Wenn die Bausteine uber Methylenbrucken in ortho-Stellung zu den phenolischen Hydroxylgruppen verknupft sind, werden jedoch auch die Esterbindungen in den Methylphenolbausteinen gespalten, obwohl die Ester von Methylphenolen und Mehrkernverbindungen, die nur Methylgruppen als Substituenten tragen, unter gleichen Bedingungen durch Ammoniak nicht angegriffen werden. In ubereinstimmung…

Photoinduced Molecular Rearrangements. The Photochemistry of Some 1,2,4-Oxadiazoles in the Presence of Nitrogen Nucleophiles. Formation of 1,2,4-Tria…

1996

The photochemistry of some 3,5-disubstituted 1,2,4-oxadiazoles in the presence of nitrogen nucleophiles [external, such as added amines or hydrazines, or internal, such as an o-aminophenyl moiety at C(3) of the oxadiazole ring] has been investigated. In the irradiation of 5-amino-(or 5-N-substituted amino) 3-phenyl-1,2,4-oxadiazoles in the presence of aliphatic primary amines (or ammonia), photolytic species arising from heterolytic cleavage of the ring O−N bond capture the nucleophilic reagent to give open-chain intermediates, which develop into 1,2,4-triazolin-5-ones. Similarly, irradiations of 3,5-diphenyl-, 3-methoxy-5-phenyl-, and 5-methyl-3-phenyl-1,2,4-oxadiazoles gave 1,2,4-triazole…