The competition between solvent–solvent and solute–solvent act on the nucleation process of 4-(methylsulfonyl)benzaldehyde

Abstract

The role of solvent in the process of crystal nucleation is crucial for crystallization process investigate, design and control. In this work, the influence of solvents on the nucleation of 4-(Methylsulfonyl)benzaldehyde (MSBZ) has been studied. An array of induction time experiments covering a range of supersaturations were carried out in four solvents. Given the same induction time, the driving forces of MSBZ for nucleation was found ranking as toluene (1784.56 J‧mol−1) > methanol (1653.93 J‧mol−1) > acetonitrile (1309.89 J‧mol−1) > acetic acid (1052.09 J‧mol−1), which is consistent with the order of the pre-exponential factor A calculated by classical nucleation theory. The binding energies of solute–solvent at site 1 increase according to the following order: acetonitrile (−19.89 kJ‧mol−1) < methanol (−26.21 kJ‧mol−1) < toluene (−27.78 kJ‧mol−1) < acetic acid (−42.09 kJ‧mol−1), which confirm that the stronger the binding of solvent and solute, the more difficult for nucleation except for acetic acid. By comparing the binding energy of solute–solvent at site 3 and the solution infrared spectroscopy, it was found that the larger the binding energy, the smaller the location of asymmetrical stretching peaks of sulfonyl group except acetic acid. The anomalous excursion of infrared spectra (1322 cm−1), the maximum attachment frequency (26.59 ln(m−3‧s−1)) and the strongest solvent–solvent interaction (−42.09 kJ‧mol−1) in acetic acid solution suggest that the competition of molecular interactions between the solvent–solvent and solute–solvent may play a big role in the nucleation process.