Synthetic, structural, spectroscopic, and stopped-flow kinetic investigation of imine production


Baran Y. , ÖZAY H. , Esener H.

PROGRESS IN REACTION KINETICS AND MECHANISM, cilt.36, ss.178-188, 2011 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 36 Konu: 2
  • Basım Tarihi: 2011
  • Doi Numarası: 10.3184/146867811x13021847366179
  • Dergi Adı: PROGRESS IN REACTION KINETICS AND MECHANISM
  • Sayfa Sayıları: ss.178-188

Özet

Synthetic and formation kinetics studies have been made of imine production from the reaction of 3-methyl-2-thiophenecarboxyaldehyde with 3-(1H-imidazol-1-yl) propan-1-amine (L-1), 1-(3-aminopropyl) pyrolidin-2-one (L-2), 2-piperazin-1-ylethanamine (L-3) and 2-hydrazinopyridine (L-4). Kinetics were determined by rapid reaction techniques using absorbance changes at multi wavelengths in methanol. Activation enthalpies for imine formation in methanol vary from 101 to 121 kJ mol(-1) and entropies of activation (DS not equal) vary from -98 to -188 J K-1 mol(-1). All of these observations are indicative of an S(N)2 mechanism. Activation parameters of the reactions were calculated under second-order reaction conditions. The analysis of kinetic data in solutions was performed with the SPECFIT/32 software package which provides useful information on the binding characteristics of functional groups and mechanism of the reactions. The crystal structure of 3-methylthiophene-2-carbaldehyde pyridine-2-ylhydrazone is described.
Synthetic and formation kinetics studies have been made of imine production from the reaction of 3-methyl-2-thiophenecarboxyaldehyde with 3-(1H-imidazol-1-yl) propan-1-amine (L1), 1-(3-aminopropyl) pyrolidin-2-one (L2), 2-piperazin-1-ylethanamine (L3) and 2-hydrazinopyridine (L4). Kinetics were determined by rapid reaction techniques using absorbance changes at multi wavelengths in methanol. Activation enthalpies for imine formation in methanol vary from 101 to 121 kJ mol-1 and entropies of activation (?S?) vary from -98 to -188 JK-1 mol-1. All of these observations are indicative of an SN2 mechanism. Activation parameters of the reactions were calculated under second-order reaction conditions. The analysis of kinetic data in solutions was performed with the SPECFIT/32 software package which provides useful information on the binding characteristics of functional groups and mechanism of the reactions. The crystal structure of 3-methylthiophene-2-carbaldehyde pyridine-2-ylhydrazone is described