Stepwise pesudopolyrotaxane nanostructure formation from supramolecular self-assembly by inclusion complexation of fast violet B with alpha- and beta-cyclodextrins

The current work deals with fast violet B (FVB) and cyclodextrins (alpha-CD and beta-CD) inclusion complex into pesudopolyrotaxane nanorod by supramolecular self-assembly. FVB/alpha-CD forms 2:2 from 1:1 and FVB/beta-CD forms 1:2 from 1:1 inclusion complexes, which further self assembled to form nanorod and nano cluster structures. The nanorods formed through step-by-step process after FVB encapsulation into cyclodextrins nano cavities. Wide angle powder X-ray diffraction exposed the crystallinity of the materials, thermal analysis, Fourier Transform Infrared Spectroscopy (FTIR) and Proton Nuclear Magnetic Resonance spectroscopy (H-1 NMR and 2D ROESY) confirmed FVB encapsulation into the CDs cavities. Amido functionality of FVB molecule is twisted when it is encapsulated within alpha-CD and beta-CD cavities. Computational studies further divulge that the complex formation is an enthalpy-entropy driven process. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

This study investigates the inclusion complex of Fast Violet B and cyclodextrins into pseudopolyrotaxane nanorods through supramolecular self-assembly. Experimental results suggest that the formation of the complex is enthalpy-entropy driven process. Various analytical methods confirm the encapsulation of FVB into cyclodextrins nano cavities and reveal the structural changes.