title: Spectrophotometric study on the proton transfer reaction between 2-amino-4-methylpyridine with 2,6-dichloro-4-nitrophenol in methanol, acetonitrile and the binary mixture 50% methanol+50% acetonitrile.
abstract: Proton transfer reaction between 2-amino-4-methylpyridine (2AMP) as the proton acceptor with 2,6-dichloro-4-nitrophenol (DCNP) as the proton donor has been investigated spectrophotometrically in methanol (MeOH), acetonitrile (AN) and a binary mixture composed of 50% MeOH and 50% AN (AN-Me). The composition of the complex has been investigated utilizing Job(')s and photometric titration methods to be 1:1. Minimum-maximum absorbance equation has been applied to estimate the formation constant of the proton transfer reaction (K(PT)) where it reached high values in the investigated solvent confirming its high stability. The formation constant recorded higher value in AN compared with MeOH and mixture of AN-Me. Based on the formation of stable proton transfer complex, a sensitive spectrophotometric method was suggested for quantitative determination of 2AMP. The Lambert-Beer(')s law was obeyed in the concentration range 0.5-8 μg mL(-1) with small values of limits of detection and quantification. The solid complex between 2AMP with DCNP has been synthesized and characterized by elemental analysis to be 1:1 in concordant with the molecular stoichiometry in solution. Further analysis of the solid complex was carried out using infrared and (1)H NMR spectroscopy.
authors.affiliation: Department of Chemistry, Faculty of Sciences - AL Faisaliah Campus, King Abdulaziz University, Jeddah, Saudi Arabia. Electronic address: khairia.alahmary@yahoo.com.
authors.forename: Khairia M
authors.initials: KM
authors.lastname: Al-Ahmary
authors.affiliation: Department of Chemistry, Faculty of Sciences - AL Faisaliah Campus, King Abdulaziz University, Jeddah, Saudi Arabia; Department of Chemistry, Faculty of Education, Alexandria University, Alexandria, Egypt.
authors.forename: Moustafa M
authors.initials: MM
authors.lastname: Habeeb
authors.affiliation: Department of Chemistry, University College - Dhiba, University of Tabuk, Dhiba, Saudi Arabia.
authors.forename: Areej H
authors.initials: AH
authors.lastname: Al-Obidan
mesh_terms: D000097:Acetonitriles / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry*; D009596:Nitrophenols / Q000737:chemistry*; D010847:Picolines / Q000737:chemistry*; D011522:Protons; D013053:Spectrophotometry
chemical_list: D000097:Acetonitriles; D009596:Nitrophenols; D010847:Picolines; D011522:Protons; C015672:2-amino-4-picoline; C015802:2,6-dichloro-4-nitrophenol; D000432:Methanol; C032159:acetonitrile
keywords: 2,6-Dichloro-4-nitrophenol; 2-Amino-4-methylpyridine; Proton transfer; Spectrophotometry