Month: November 2023

Foces-Foces, Concepcion et al. published their research in Acta Crystallographica, Section B: Structural Science in 2000 | CAS: 5334-39-4

3-Methyl-4-nitro-1H-pyrazole (cas: 5334-39-4) belongs to pyrazole derivatives. The 1H-pyrazole provides an excellent means by which to provide the requisite hydrogen bond acceptor閳ユ徆onor motifs, whether as a monocyclic ring or as a fused indazole ring. Protonation of pyrazole in strong acid leads to pyrazolium cations, which undergo electrophilic substitution preferentially at C3 rather than C4. The pyrazole anion is not reactive toward nucleophiles but is mostly reactive to electrophiles.SDS of cas: 5334-39-4

Supramolecular structure of 1H-pyrazoles in the solid state: a crystallographic and ab initio study was written by Foces-Foces, Concepcion;Alkorta, Ibon;Elguero, Jose. And the article was included in Acta Crystallographica, Section B: Structural Science in 2000.SDS of cas: 5334-39-4 This article mentions the following:

The secondary structure of 1H-unsubstituted pyrazole derivatives bearing only one hydrogen-donor group and one or more acceptor groups has been analyzed in terms of some descriptors representing the substituents at C3 and C5. The substituent at C4 appears to affect mainly the tertiary or quaternary structure of these compounds The proposed semi-quant. model, which explains most hydrogen-bonded motifs as a combination of the effects of substituents at C3 and C5, has also been examined as a function of the steric and polarizability effects of these substituents represented by molar refractivity. The model also applies to other five-membered rings (1,2,4-triazoles, 1,2,4-diazaphospholes and 1,2,4-diazaarsoles). Furthermore, ab initio calculations at RHF/6-31G* have been performed to discover the relative stability of three of the four hydrogen-bond patterns displayed by several sym. pyrazoles (dimers, trimers, tetramers). The fourth motif, catemers, has only been discussed geometrically. In the experiment, the researchers used many compounds, for example, 3-Methyl-4-nitro-1H-pyrazole (cas: 5334-39-4SDS of cas: 5334-39-4).

3-Methyl-4-nitro-1H-pyrazole (cas: 5334-39-4) belongs to pyrazole derivatives. The 1H-pyrazole provides an excellent means by which to provide the requisite hydrogen bond acceptor閳ユ徆onor motifs, whether as a monocyclic ring or as a fused indazole ring. Protonation of pyrazole in strong acid leads to pyrazolium cations, which undergo electrophilic substitution preferentially at C3 rather than C4. The pyrazole anion is not reactive toward nucleophiles but is mostly reactive to electrophiles.SDS of cas: 5334-39-4

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics