Study on beta-cyclodextrin inclusion of Zn(II) aromatic complex and its analytical application

Area of Science:

• Supramolecular Chemistry
• Analytical Chemistry
• Materials Science

Background:

• Beta-cyclodextrin (beta-CD) is a cyclic oligosaccharide with a hydrophobic cavity, widely used in host-guest chemistry.
• 2-hydroxy-1-naphthoic acid (2H1NA) is an aromatic compound with potential applications but requires sensitive detection methods.
• Zinc complexes can form stable supramolecular structures with cyclodextrins.

Purpose of the Study:

• To synthesize and characterize a new beta-cyclodextrin inclusion compound with a zinc aromatic complex.
• To investigate the formation mechanism of the supramolecular system.
• To develop a spectrofluorimetric method for determining 2H1NA in aqueous solutions.

Main Methods:

• Synthesis of the beta-cyclodextrin inclusion compound Zn(2H1NA)(2)x 2beta-CD.
• Structural characterization using 1H NMR, IR, fluorescence spectra, TG-DTA, and elementary analysis.
• Spectrofluorimetric analysis to study the formation mechanism and develop a quantitative method.

Main Results:

• The formation of a 2:1 host-guest compound with naphthalene ring encapsulation was confirmed.
• An inclusion constant of 1.27 x 10^4 (L/mol)^2 was determined.
• A sensitive spectrofluorimetric method for 2H1NA determination was established with a linear range of 9.00 x 10^-7 to 2.50 x 10^-5 mol/L and a detection limit of 8.00 x 10^-7 mol/L.

Conclusions:

• The study successfully prepared and characterized a novel beta-cyclodextrin inclusion complex.
• The developed spectrofluorimetric method offers high sensitivity and accuracy for 2H1NA determination.
• The method's applicability was validated by successful analysis of 2H1NA in wastewater samples with high recovery rates.