Novel Schiff Bases of Pyrrole: Synthesis, Experimental and Theoretical Characterizations, Fluorescent Properties and Molecular Docking

Some new Schiff-base compounds based on pyrrole were synthesized by the reaction of 2-amino-1-methyl-4,5-diphenyl-1H-pyrrole-3-carbonitrile (1)with aromatic aldehydes (2a-2e) in ethanol/acetic acid at room temperature. The structures of the Schiff bases were characterized by full spectral data. The fluorescence emission intensity of the Schiff bases has been measured in different polar solvents (protic and aprotic) at different temperatures and also pHs. Among the products of this reaction, 2-[(2-hydroxy-benzylidene)-amino]-1-methyl-4,5-diphenyl-1H-3-carbonitrile(3a) exhibited good results. The molecular docking studies on all Schiff bases revealed that the compound 3a forms a stable complex with polo-like kinase1 as a target and gives a binding affinity value of -8.9 kcal/mol. According to the obtained results, the DFT calculations carried out on 3a by using B3LYP/6-31+G(d,p) level of theory which the theoretical data were in good agreement with the experimental data. Furthermore, the NBO analysis showed the electron transfers correctly.