Квантово-хімічний аналіз термодинамічних параметрів димеризації ?-гідроксікислот на міжфазній поверхні повітря/вода

• Datum: 2012
• 1. Verfasser: Fomina, E. S.
• Format: Artikel
• Sprache: Englisch
• Veröffentlicht: Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine 2012
• Online Zugang: https://www.cpts.com.ua/index.php/cpts/article/view/189
• Назва журналу: Chemistry, Physics and Technology of Surface

In the framework of quantum chemical semiempirical method PM3 the thermodynamic and structural parameters of formation and dimerization have been calculated for homochiral ?-hydroxy acids with general formula CnH2nОНCOОH (n = 6–16). On the basis of five optimized monomer structures, dimers with ‘serial’ and ‘parallel’ order of monomer functional groups were built. The tilt angles between hydrocarbon radical and normals to the p- and q-directions of the interface in regarded dimer structures have been shown to be ? = 8.9°–21.0° and ? = 9.8°–20.9° dependently on the monomer structure of basic dimer. It has been shown that thermodynamic parameters of dimerization depend on the length of alkyl chain by stepwise and formation of ‘parallel’ dimers is more energetically preferred. Using dependencies of thermodynamic parameters of dimerization, it is possible to make an assumption about further path of the clusterization process of ?-hydroxy acids via preferred formation of linear aggregates on the base of ‘parallel’ dimers.