Calculations of Complexes of 9-Diphenylaminoacridine Fluorescent Indicator with Analyte Molecules Using Density Functional Theory with Dispersion Correction

摘要

The interaction between 9-diphenylaminoacridine dye (indicator) and several small analyte molecules (methanol, acetonitrile, acetone, tetrahydrofuran, benzene, ammonia, formaldehyde, and acetaldehyde) was studied theoretically in regards to the problem of the development of optical chemosensors based on organic dyes. The structures and formation energies of 9-diphenylaminoacridine (DPAA) complexes with analytes were calculated by the density functional theory (DFT) method, including the empirical dispersion correction (DFT-D) with the use of the B97-D exchange—correlation functional. Complexes of the lateral and stacking types were considered; for the latter, the absorption spectra calculated previously correlate with the experimental fluorescence spectra of 9-diphenylaminoacridine in corresponding solvents. It was demonstrated that the inclusion of the dispersion correction significantly increases the calculated values of binding energies for all DPAA complexes with analytes and, for most complexes, makes stacking structures energetically more favorable than lateral structures.