1H NMR and X-ray crystallographic analysis of 1,2-bis(4,6-diethylthio-1 H-pyrazolo[3,4- d]pyrimidin-1-yl)ethane and its ‘propylene linker’-analog: molecular recognition versus crystal engineering

Abstract

Proton NMR analysis on newly synthesized 1,2-bis(4,6-diethylthio-1 H-pyrazolo[3,4- d]pyrimidin-1-yl)ethane, 2c , and 1,2-bis(4,6-diethylthio-1 H-pyrazolo[3,4- d]pyrimidin-1-yl)propane, 2d , showed intramolecular stacking in solution. X-Ray crystallography on 2c and 2d , however, confirmed the presence of such intramolecular stacking only in case of the ‘propylene linker’ compound, 2d , while the ‘ethylene linker’ compound, 2c , was devoid of it.