Para-halogenated benzaldehyde molecules included in cyclodextrins: a combined spectroscopic and thermal analysis

• Autor(a) principal: Ribeiro-Claro, Paulo J. A.
• Data de Publicação: 2006
• Outros Autores: Costa, António M. Amorim da, Vueba, Manuel L., Pina, M. Eugénia, Amado, Ana M.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10316/8280; https://doi.org/10.1002/jrs.1419

The inclusion complexes of 4-X-benzaldehyde guests (X = F, Cl, Br) in alpha-, beta-and gamma-cyclodextrins (alphaCD, betaCD and gammaCD) were prepared and characterized by means of thermogravimetry, differential scanning calorimetry (DSC) and vibrational spectroscopy. The stoichiometry of the inclusion complexes ranges from 2:1 to 1:2, depending on the cavity size of the host. Sensitive vibrational modes such as C-O and ring CH stretching modes were used to monitor the effects of the inclusion process and to assess the preferred inclusion geometry for each host-guest pair. On the whole, the spectral observations suggest that the small alphaCD cavity imposes important structural restrictions on the guest molecule, while the larger gammaCD cavity allows lsquoliquid-typersquo intermolecular contacts. Copyright © 2005 John Wiley & Sons, Ltd.