Inclusion complexes of cyclodextrins with 4-amino-1,8-naphthalimides (part 2)

Author(s)

Goncalves Silva, Barbara Perez ; Marcon, Rodrigo Oliveira ; Brochsztain, Sergio

• Document type: Journal article
• Source: JOURNAL OF INCLUSION PHENOMENA AND MACROCYCLIC CHEMISTRY; v. 68, n. 3-4, p. 10-pg., 2010-12-01.

Abstract

Fluorescence spectroscopy was used to characterize inclusion compounds between 4-amino-1,8-naphthalimides (ANI) derivatives and different cyclodextrins (CDs). The ANI derivatives employed were N-(12-aminododecyl)-4-amino-1,8-naphthalimide (mono-C(12)ANI) and N,N'-(1,12-dodecanediyl)bis-4-amino-1,8-naphthalimide (bis-C(12)ANI). The CDs used here were alpha-CD, beta-CD, gamma-CD, HP-alpha-CD, HP-beta-CD and HP-gamma-CD. The presence of CDs resulted in pronounced blue-shifts in the emission spectra of the ANI derivatives, with increases in emission intensity. This behavior was parallel to that observed for the dyes in apolar solvents, indicating that inclusion complexes were formed between the ANI and the CDs. Mono-C(12)ANI formed inclusion complexes of 1:1 stoichiometry with all the CDs studied. Complexes with the larger CDs (HP-beta-CD, HP-gamma-CD and gamma-CD) were formed by inclusion of the chromophoric ANI ring system, whereas the smaller CDs (alpha-CD, HP-alpha-CD and beta-CD) formed complexes with mono-C(12)ANI by inclusion of the dodecyl chain. Bis-C(12)ANI formed inclusion complexes of 1:2 stoichiometry with HP-beta-CD, HP-gamma-CD and gamma-CD, but did not form inclusion complexes with alpha-CD, HP-alpha-CD and beta-CD. The data were treated in the case of the large CDs using a Benesi-Hildebrand like equation, giving the following equilibrium constants: mono-C(12)ANI:HP-beta-CD (K (11) = 50 M-1), mono-C(12)ANI:HP-gamma-CD (K (11) = 180 M-1), bis-C(12)ANI:HP-beta-CD (K (12) = 146 M-2), bis-C(12)ANI:HP-gamma-CD (K (12) = 280 M-2). (AU)

• FAPESP's process: 08/57940-7 - Biofuel production by photochemical cracking of vegetable oils employing aromatic imides supported on mesoporous silicates as sensitizers
• Grantee: Sergio Brochsztain
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Regular Program Grants