We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Synthesis and spectroanalytical studies of a new heterocyclic acid-base indicator.
- Authors
Razmara, Samira; Pordel, Mehdi; Ebrahimi, Mahmoud
- Abstract
[Figure not available: see fulltext.] New purple dyes of the imidazopyridine series were synthesized by the reaction of 6-chloro-3-nitroimidazo[1,2- a]pyridine with arylacetonitriles in basic MeOH solution via nucleophilic substitution of hydrogen atom. The obtained 2-aryl-2-[6-chloro-3-(hydroxyimino) imidazo[1,2- a]pyridin-2(3 H)-ylidene)]acetonitriles were further converted to new 8-chloropyrido[2',1':2,3]imidazo[4,5- b]-quinoline-12-carbonitriles. The solution of 2-[6-chloro-3-(hydroxyimino)imidazo[1,2- a]pyridin-2(3 H)-ylidene)]-2-(4-methylphenyl)acetonitrile undergoes a reproducible color change due to the addition of acid or base. A UV-Vis spectroscopic characterization and acid-base equilibrium study of this dye was carried out with the view of its possible use as an indicator. The results show that this dye is an amphoteric substance with two ionization constants K and K indicative of weak basic and acidic properties. The p K and p K values in aqueous solution determined by spectrophotometric method are 2.43 and 9.73, respectively. A comparison was made with existing acid-base indicators effective over the same pH range.
- Subjects
HETEROCYCLIC compounds synthesis; PYRIDINE synthesis; ORGANIC dyes; ACIDIMETRIC titration; NUCLEOPHILIC substitution reactions
- Publication
Chemistry of Heterocyclic Compounds, 2015, Vol 51, Issue 8, p713
- ISSN
0009-3122
- Publication type
Article
- DOI
10.1007/s10593-015-1764-8