Research On The Formation Mechanism Of Dicumyl Peroxide Crystal Defects

The study of crystal defects is an important branch in the field of crystallography.The crystal defects inside the crystal will have a huge impact on the chemical purity and crystal performance of the product,but so far the research on the formation mechanism of organic small molecule crystal defects is not clear.In this topic,dicumyl peroxide is selected as a model drug,and the mechanism of crystal defect formation in the process of crystal growth is explored through the study of the key factors in the process of crystal defect formation.The solubility data of dicumyl peroxide in seven pure organic solvents and two binary solvents was determined by gravimetric analysis.The solubility of dicumyl peroxide in the seven pure solvents increases rapidly with the increase of temperature,and the solubility in the binary solvent mixture increases with the increase of the organic phase content.The solubility data was correlated with four thermodynamic models,and the results showed that the calculation results of the NRTL model were the most consistent with the experimental data.The thermodynamic data of the mixing process is calculated by the NRTL model,and it is determined that the mixing process of dicumyl peroxide in the investigated solvent system is spontaneous and driven by entropy.The crystal morphology and crystal defect types of the obtained products were monitored with the help of an optical microscope,and it was found that the three crystal habit products obtained in different solvents all had different degrees of crystal defects.Through optical microscope and micro-Raman spectroscopy,it is determined that the defects are inclusions containing the crystallization mother liquor.The study found that lower temperature and supersaturation are beneficial to reduce the formation of defects during crystal growth.In the solvent after degassing treatment,the growth rate of crystals dropped sharply and the liquid inclusions inside the crystals were significantly reduced.In the gas bubbling experiment,it was found that it was prepared in methanol solvent treated with nitrogen,air,carbon dioxide and oxygen.The relationship between the number of inclusions in the crystal is consistent with the relationship between the oxygen content of the gas used.The variation of macroscopic inclusions inside dicumyl peroxide crystals with temperature was studied by a hot stage microscope.The crystal face index of each crystal face of dicumyl peroxide is determined by crystal habit simulation.The crystal defects mainly exist on the {(-1 0 2)} and {(-1-11)} faces,which are calculated by the AE model The improved adhesion energy and relative growth rate of each crystal face were studied,the molecular arrangement of each crystal face of dicumyl peroxide crystals and the interaction between crystal faces and solvents were studied.The Adsorption Locator module was used to simulate the gas adsorbed on the crystal surface.It is found that the formation of {(-1 0 2)} and {(-1-1 1)} face defects is related to their higher roughness and faster growth rate,and the specific adsorption behavior of the dissolved gas in the solution on the crystal face will also have a certain impact.