Thermoanalytical study of O,O '-dibenzoyl-(2R,3R)-tartaric acid supramolecular compounds. Part I. Investigation of compounds with water, achiral alcohols and phenols

Thermal behaviour of O,O'-dibenzoyl-(2R,3R)-tartaric acid (DBTA), its monoh ydrate, and its potential supramolecular compounds with achiral alcohols an d phenols were investigated with TG, DSC, EGD. The structural differences a mong the anhydrous DBTA, its monohydrate, and the supramolecular derivative s were investigated with X-ray powder diffraction. The thermal behaviour of DBTA-supramoleculars with isopropyl, tert-butyl, and 5-cyclohexyl alcohols is found to be similar to each other but essentially different from that o f both DBTA and its monohydrate. On heating they melt and decompose between 60-180 degreesC while they loose in one or two steps the bound alcohol. Th e thermal stability of the supramolecular compounds increases with the boil ing point of the alcohol component. According to the X-ray powder diffracti on patterns each supramolecular substance has different structure, that may also result in the different thermal stability of the compounds. The molar ratio of DBTA:achiral alcohol samples is 1:1.01-1:1.57 estimated from the corresponding mass losses. The XRD patterns of the prepared two DBTA-phenol materials are different from those of DBTA-achiral alcohol samples. The ph enol compounds melt with slow mass losses and give an endothermic peak betw een 73-83 degreesC but the melting point of the anhydrous DBTA cannot be ob served. DBTA:phenol molar ratio is estimated to be 1:0.41 and 1:0.65 for ph enol and 2-methylphenol, respectively.