A facile synthesis of seven-membered N, O-ligands and their optical properties.

Seven-membered N, O-ligands containing ketone and pyrrole have been designed and synthesized via a facile method using organocatalyst, piperidinium acetate or L-proline. Their photophysical properties including absorption and emission spectra have been investigated in eight kinds of different polar solvents. DFT and TD-DFT calculations have also been carried out to further demonstrate the geometric structures and illuminate their extraordinary photochemical properties. The calculations show that ESIPT process is prohibited in both compounds NOAB-1, 2 which is confirmed by experiment and calculation due to its stable ketone structure. Image 1 • Two seven-membered N, O-ligands (NOABs) have been synthesized by a facile method. • Photophysical properties are discussed by experiment and calculation. • ESIPT process of NOABs is prohibited which is confirmed by this work. [ABSTRACT FROM AUTHOR]