Tautomerism in azo dyes: Border cases of azo and hydrazo tautomers as possible NMR reference compounds

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F62690094%3A18470%2F19%3A50015531" target="_blank" >RIV/62690094:18470/19:50015531 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/abs/pii/S0143720818313536" target="_blank" >https://www.sciencedirect.com/science/article/abs/pii/S0143720818313536</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.dyepig.2019.02.015" target="_blank" >10.1016/j.dyepig.2019.02.015</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Tautomerism in azo dyes: Border cases of azo and hydrazo tautomers as possible NMR reference compounds

Popis výsledku v původním jazyce

In order to meet the need for NMR reference compounds in the study of tautomeric azo dyes, two series of azo dyes, derived from 3-methyl-1-phenyl-4-(phenyldiazenyl)-1H-pyrazol-5-amine and 5-methy1-2-pheny1-4-(2-phenylhydrazono)-2,4-dihydro-3H-pyrazol-3-one, have been studied by using molecular spectroscopy (UV-Vis and NMR) and quantum-chemical calculations (M06-2X/TZVP) in solution. The results clearly indicate that 3-methyl-1-phenyl-4-(phenyldiazenyl)-1H-pyrazol-5-amines are present in pure azo tautomeric form, while 5-methyl-2-pheny1-4-(2-phenylhydrazono)-2,4-dihydro-3H-pyrazol-3-ones exist as hydrazone tautomers. The tautomeric state is not substantially influenced by nitro group substitution in the phenyl ring. Consequently, the studied compounds can be used as model tautomers in the NMR evaluation of the tautomeric state in various azo dyes in solution. According to the crystallographic data (obtained by us or available in the literature) the conclusions about the tautomerism of the studied compounds in solution are valid in solid state as well.

Název v anglickém jazyce

Tautomerism in azo dyes: Border cases of azo and hydrazo tautomers as possible NMR reference compounds

Popis výsledku anglicky

In order to meet the need for NMR reference compounds in the study of tautomeric azo dyes, two series of azo dyes, derived from 3-methyl-1-phenyl-4-(phenyldiazenyl)-1H-pyrazol-5-amine and 5-methy1-2-pheny1-4-(2-phenylhydrazono)-2,4-dihydro-3H-pyrazol-3-one, have been studied by using molecular spectroscopy (UV-Vis and NMR) and quantum-chemical calculations (M06-2X/TZVP) in solution. The results clearly indicate that 3-methyl-1-phenyl-4-(phenyldiazenyl)-1H-pyrazol-5-amines are present in pure azo tautomeric form, while 5-methyl-2-pheny1-4-(2-phenylhydrazono)-2,4-dihydro-3H-pyrazol-3-ones exist as hydrazone tautomers. The tautomeric state is not substantially influenced by nitro group substitution in the phenyl ring. Consequently, the studied compounds can be used as model tautomers in the NMR evaluation of the tautomeric state in various azo dyes in solution. According to the crystallographic data (obtained by us or available in the literature) the conclusions about the tautomerism of the studied compounds in solution are valid in solid state as well.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10401 - Organic chemistry

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Dyes and pigments

ISSN

0143-7208

e-ISSN

—

Svazek periodika

165

Číslo periodika v rámci svazku

JUN 2019

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

7

Strana od-do

157-163

Kód UT WoS článku

000463979700022

EID výsledku v databázi Scopus

2-s2.0-85061758241