Solute–solvent interaction effects on second-order rate constants of reaction between 1-chloro-2,4-dinitrobenzene and aniline in alcohol–water mixtures

✍ Scribed by M. Harati; M. R. Gholami

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 114 KB
• Volume: 37
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.20041

✦ Synopsis

Abstract

The second‐order rate coefficients for aromatic nucleophilic substitution reaction between 1‐chloro‐2,4‐dinitrobenzene and aniline have been measured in aqueous solutions of ethanol and methanol at 25°C. The plots of rate constants versus mole fraction of water show a maximum in all‐aqueous solutions. The effect of four empirical solvent parameters including hydrogen bond donor acidity (α) dipolarity/polarizability (π^*^) normalized polarity (E^N^~T~) and solvophobicity (Sp) has been investigated. This investigation has been carried out by means of simple and multiple regression models. A dual‐parameter equation of log k~2~ versus Sp and α was obtained in all‐aqueous solutions (n = 41, r = 0.962, s = 0.053, p = 0.0000). This equation shows that solvophobicity and hydrogen bond donor acidity are important factors in the occurrence of the reaction and they have opposite effects on reaction rate. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 37: 90–97, 2005