DENSITY FUNCTIONAL THEORY INVESTIGATIONS FOR THE ELECTRONIC AND VIBRATIONAL PROPERTIES OF DONOR-ACCEPTOR SYSTEM

This work deals with designing, structure, electronic and vibrational properties of various molecular (N-dimethyl benzene (C8H11N), Cyanobenzene-N (C7H5N), and C8H11N-C7H5N as a donor, acceptor, and donor- acceptor molecular system, respectively. Density Functional Theory (DFT) with B3LYP level was employed with various basis sets to investigate the electronic and vibrational properties of these molecular systems. The quantum calculations include the total energy, symmetry, dipole moment, average polarizability, electronic states (HOMO and LUMO), energy gap, ionization potential, electron affinity, electronegativity, electrophilicity index, charge transfer, and IR spectrum. The results show that the energy gap of the donor-acceptor system less than the donor and acceptor. We found out that the 6-311G basis set of theory gave a good agreement with experimental data. Also, we found out a very interesting results, which is a new donor-acceptor molecular system has more reactive in charge transfer process and has good semiconductor properties to using as molecular electronics and organic solar cell.