Nanostructures formed by cyclodextrin covered aminobenzophenones through supramolecular self assembly

Abstract

Cyclodextrin (α and β) based nanostructures formed with 2-aminobenzophenone, 3-aminobenzophenone through the supramolecular self assembly are studied by absorption, fluorescence, time-resolved fluorescence, SEM, TEM, FT-IR, DSC, PXRD and 1H NMR. The unequal layer by layer nanosheets and nanoribbons are formed through self assembly of 3ABP/CD inclusion complexes. 2ABP/α-CD complex nanostructures show the self assembly hierarchical thread structure and β-CD complexes displays a nanobrick structure. The formation of nanostructures are prearranged to HO⋯H, NH2⋯O and H2N⋯H intermolecular hydrogen bond between individual complexes. The absorption and fluorescence spectral changes explicit formation of 1:1 inclusion complexes and solvent study demonstrate the ESIPT and TICT present in both molecules. The thermodynamic parameters (ΔH, ΔG and ΔS) of 2ABP and 3ABP molecule and the inclusion complexes were determined from semiempirical PM3 calculations.