Azo dye/cyclodextrin: new findings of identical nanorods through 2:2 inclusion complexes.
Inclusion complexation behavior of 4-aminoazobenzene (AAB) and 4-amino-2,3'-dimethyl azobenzene (GBC, fast grant GBC) with α- and β-cyclodextrins (α-CD, β-CD) is analyzed by scanning electron microscope, transmission electron microscope, Fourier transform infrared spectroscopy, differential scanning calorimetry, powder X-ray diffraction, and proton nuclear magnetic resonance spectroscopy techniques. Transmission electron microscope analysis suggests that identical nanorods formed in AAB/CD inclusion complexes while different dimension nanostructures were observed in GBC/CD inclusion complexes. The nanostructures confirmed that the ratio of 2:2 (guest:host) inclusion complex has been developed to a miniature nanorod. Nanosecond time-resolved fluorescence studies indicated that AAB/GBC have fast life time in water, whereas slow life time in CDs corresponds to a higher-order structure of 2:2 complexes. Thermodynamic parameters and binding affinity of the inclusion complex formation were determined and discussed. van der Waals interactions are mostly responsible for enthalpy-driven complex formation of AAB and GBC with cyclodextrins.
Department of Chemistry, Annamalai University, Annamalai Nagar 608 002, India. Electronic address: drrajendiran@rediffmail.com.
N
N
Rajendiran
Department of Chemistry, Annamalai University, Annamalai Nagar 608 002, India.
R K
RK
Sankaranarayanan
D002152:Calorimetry, Differential Scanning; D006860:Hydrogen Bonding; D008854:Microscopy, Electron; D008958:Models, Molecular; D015394:Molecular Structure; D043942:Nanotubes / Q000737:chemistry*; D066244:Proton Magnetic Resonance Spectroscopy; D012996:Solutions; D013053:Spectrophotometry; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D047391:alpha-Cyclodextrins / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000737:chemistry*; D010128:p-Aminoazobenzene / Q000737:chemistry*; D004124:p-Dimethylaminoazobenzene / Q000737:chemistry*
D012996:Solutions; D047391:alpha-Cyclodextrins; D047392:beta-Cyclodextrins; D010128:p-Aminoazobenzene; D004124:p-Dimethylaminoazobenzene; C031215:betadex; C032613:alpha-cyclodextrin
Azo dyes; Cyclodextrin; Inclusion complex; Molecular modeling; Nanorod; Self-assembly