A model study of dickite intercalated with formamide and N-methylformamide

Author(s)
Eva Scholtzova, Lubomir Benco, Daniel Tunega
Abstract

Local geometry and orientation of intercalated molecules of formamide (FA) and N-methylformamide (NMFA) in the clay mineral dickite (D) was studied by means of Density Functional Theory (DFT) calculations. Ten configurations with different orientation of the intercalated molecule were investigated for both D_FA and D_NMFA intercalates. Four groups of relaxed structures sorted by the calculated total electronic energy were found in both cases. The experimental geometry of the D_FA intercalate was denoted as the most stable structure from the investigated models. The differences in the total electronic energy of all D_FA configurations are within the interval of ∼92 kJ/mol. On one hand FA forms intercalates specifically and a close relation between the orientation of the FA molecules in the interlayer space and the stability of a particular configuration has been observed. On the other hand, N-methylformamide forms intercalated structures non-specifically. Small differences in the total energy, not larger than 18 kJ/mol, are observed for different orientations of the NMFA molecules The reorientation of the intercalated molecules has only a small effect on the stabilization of the D_NMFA intercalate what is in contrast with the D_FA intercalate. It was also observed that the experimental D_NMFA configuration is not the most stable. A small variation of the total electronic energy of different configurations correlates with small changes of the orientation of the dipole moment of the intercalated NMFA molecule.

Organisation(s)
Computational Materials Physics, Department of Theoretical Chemistry
External organisation(s)
Slovenian Academy of Sciences and Arts
Journal
Physics and Chemistry of Minerals
Volume
35
Pages
299-309
No. of pages
11
ISSN
0342-1791
DOI
https://doi.org/10.1007/s00269-008-0223-9
Publication date
2008
Peer reviewed
Yes
Austrian Fields of Science 2012
103015 Condensed matter, 104022 Theoretical chemistry
Portal url
https://ucrisportal.univie.ac.at/en/publications/6988a3c6-b618-4289-9395-6913e8af74e3