Combined experimental powder X-ray diffraction and DFT data to obtain the lowest energy molecular conformation of friedelin

• Autor(a) principal: Oliveira,Djalma Menezes de
• Data de Publicação: 2012
• Outros Autores: Mussel,Wagner da Nova, Duarte,Lucienir Pains, Silva,Grácia Divina de Fátima, Duarte,Hélio Anderson, Gomes,Elionai Cassiana de Lima, Guimarães,Luciana, Vieira Filho,Sidney A.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Química Nova (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422012001000005
• topic: powder X-ray diffraction; conformational study; friedelin

Friedelin molecular conformers were obtained by Density Functional Theory (DFT) and by ab initio structure determination from powder X-ray diffraction. Their conformers with the five rings in chair-chair-chair-boat-boat, and with all rings in chair, are energy degenerated in gas-phase according to DFT results. The powder diffraction data reveals that rings A, B and C of friedelin are in chair, and rings D and E in boat-boat, conformation. The high correlation values among powder diffraction data, DFT and reported single-crystal data indicate that the use of conventional X-ray diffractometer can be applied in routine laboratory analysis in the absence of a single-crystal diffractometer.