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Enzyme
Compound
Pivot Concepts:
Gene/Protein
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Target Concepts:
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Query: EC:4.1.2.42 (
DTA
)
1,693
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
A convenient access to 5-(trinitromethyl)-2H-tetrazole (HTNTz) has been developed, based on the exhaustive nitration of 1H-tetrazole-5-acetic acid, which was prepared from
ethyl cyanoacetate
and HN3 in a 1,3-dipolar cycloaddition reaction, followed by basic hydrolysis. HTNTz was converted into the ammonium, guanidinium, rubidium, cesium, copper, and silver 5-(trinitromethyl)-2H-tetrazolates. In addition, the ammonia adducts of the copper and silver salts were isolated. The reaction of HTNTz with hydrazine and hydroxylamine resulted in the formation of hydrazinium 5-(dinitromethyl)tetrazolate and hydroxylammonium 5-(dinitromethyl)-1H-tetrazolate, respectively. Acid treatment of both 5-(dinitromethyl)tetrazolates resulted in the isolation of 5-(dinitromethylene)-4,5-dihydro-1H-tetrazole, which was converted into potassium 5-(dinitromethyl)-1H-tetrazolate by reaction with K2CO3. All prepared compounds were fully characterized by (1)H, (13)C, (14)N, and (15)N NMR spectroscopy and X-ray crystal structure determination. Initial safety testing (impact, friction, and electrostatic sensitivity) and thermal stability measurements (differential thermal analysis,
DTA
) were also carried out. The 5-(trinitromethyl) and 5-(dinitromethyl)tetrazoles are highly energetic materials that explode upon impact or heating.
...
PMID:Energetic high-nitrogen compounds: 5-(trinitromethyl)-2H-tetrazole and -tetrazolates, preparation, characterization, and conversion into 5-(dinitromethyl)tetrazoles. 2372 11
In recent years, great attention has been dedicated to the development of heterogeneous base catalysts providing a green and sustainable process in benign aqueous media. Herein, the ionic liquid modified layered double hydroxide (LDH) based catalysts of LDH-IL-Cn (n = 4, 8, 12) were prepared by adopting an exfoliation/assembly strategy, in which the ionic liquids (ILs) were covalently anchored onto the surface of LDH layers. The resulting LDH-IL-Cn were characterized by FT-IR, solid-state
13
C NMR,
29
Si CP/MAS NMR,
27
Al-MAS NMR, XRD, TG-
DTA
, BET, XPS, SEM, CO
2
-TPD, contact angle experiments, etc. The catalytic performance of LDH-IL-C12 for the Knoevenagel condensation of a variety of aldehydes with
ethyl cyanoacetate
/malononitrile in H
2
O at room temperature showed excellent yields and selectivities. Moreover, the base catalyst of LDH-IL-C12 can be easily recycled and reused for at least 5 times without the decrease of its catalytic efficiency. The scaled-up experiments revealed that the catalyst retained its efficiency and robustness.
...
PMID:Layered double hydroxide anchored ionic liquids as amphiphilic heterogeneous catalysts for the Knoevenagel condensation reaction. 2918 48
