29114-35-0Relevant academic research and scientific papers
On the Physicochemical Characterization of 5-Amino-1-aryl-1H-tetrazoles: Electronic Molecule Parameters from the Thermal Isomerization into 5-Arylamino-1H-tetrazoles
Schelenz, Thomas,Schaefer, Wieland
, p. 197 - 200 (2007/10/03)
The known thermal isomerization of 5-amino-1-aryl-1H-tetrazoles (A) into corresponding 5-arylamino-1H-tetrazoles (HB) was used to derive physicochemical parameters characterizing the electronic substituent effect on isomerism and dissociation equilibria. For a series of 26 tetrazoles A as starting materials the equilibrium constants (pKi) of isomerization in boiling ethylene glycol at 197°C and the dissociation constants (pKa) of the NH-acidic tetrazoles HB were determined by potentiometric titration of rapidly cooled equilibrium mixtures in water and ethanol/water with KOH at 25°C. The pK values are closely correlated with Hammett's electronic substituent constants σ and can be used as electronic molecule parameters in QSAR or QSPR (QSAR = quantitative structure-activity relationship; QSPR = quantitative structure-property relationship) studies.
