Computational studies of molecular charge transfer complexes of heterocyclic 4-methylepyridine-2-azomethine-p-benzene derivatives with picric acid and m-dinitrobenzene

•Computational studies of molecular charge transfer complexes.•Between aryl Schiff bases as donor and m-dinitrobenzene and picric acid as acceptors.•The optimized structures for donors, acceptors and CTCs obtained from PM3 calculations.•Vibrational modes, absorption bands and 1H NMR spectra were calculated by HF and DFT.•The results of HF and DFT give good agreement to the experimental results.

Charge transfer complexes of substituted aryl Schiff bases as donors with picric acid and m-dinitrobenzene as acceptors were investigated by using computational analysis calculated by Configuration Interaction Singles Hartree–Fock (CIS-HF) at standard 6-31G∗ basis set and Time-Dependent Density-Functional Theory (TD-DFT) levels of theory at standard 6-31G∗∗ basis set, infrared spectra, visible and nuclear magnetic resonance spectra are investigated. The optimized geometries and vibrational frequencies were evaluated. The energy and oscillator strength were calculated by Configuration Interaction Singles Hartree–Fock method (CIS-HF) and the Time-Dependent Density-Functional Theory (TD-DFT) results. Electronic properties, such as HOMO and LUMO energies and band gaps of CTCs set, were studied by the Time-Dependent density functional theory with Becke–Lee–Young–Parr (B3LYP) composite exchange correlation functional and by Configuration Interaction Singles Hartree–Fock method (CIS-HF). The ionization potential Ip and electron affinity EA were calculated by PM3, HF and DFT methods. The columbic force was calculated theoretically by using (CIS-HF and TD-DFT) methods. This study confirms that the theoretical calculation of vibrational frequencies for (aryl Schiff bases – (m-dinitrobenzene and picric acid)) complexes are quite useful for the vibrational assignment and for predicting new vibrational frequencies.

Graphical abstractThe structural formula of the charge transfer complexes of aryl Schiff bases with m-dinitrobenzene and picric acid.Figure optionsDownload full-size imageDownload as PowerPoint slide