Theoretical investigation of geometric and spectroscopic properties of some 2-aminobenzimidazole complexes

2-Aminobenzimidazole (ABZ) that is used in antiseptic medicines and as a base molecule of various complex molecules, Picric Acid PA) which is used in paint industry, agricultural medicines, produce of colored glass and textile products, Trinitrobenzene(TNB) used as an explosive material in military and mining sector and complex molecules 2-Aminobenzimidazole-Trinitrobenzene (ABZ-TNB) and 2-Aminobenzimidazole-Picric Acid (ABZ-PA) are theoretically studied. As an inception Gaussian 03W and GaussView 3.0 program pack are used to draw theoretically the most optimized and stable 3D structures of molecules in density functional theory (DFT/B3LYP-PBE1PBE) and Hartree-Fock (HF) methods with 6-31++G(d,p) basis set. Then structure parameters (bond length and bond angles), infrared vibration frequencies, 13C and 1H chemical shift data of molecules are calculated in three different methods. Although there are only characteristic experimental data of molecules, all vibration modes and chemical shift data are theoretically calculated. Electronic properties of molecules: HOMO, LUMO energies, molecular hardness, electronegativity values and UV-Vis spectra data are calculated in three different methods and compared with corresponding data. In ABZ-TNB and ABZ-PA complexes, intermolecular interactions and possible hydrogen bonds between complexes are evaluated by considering. As a result, while the DFT methods are obtained to be in good agreement with experimental data, the HF method is better for UV-Vis spectra data.