Study of Geometrical Optimization and Some Energies of Coronene and it is Adducts

In this work, the calculations of geometrical parameters and some energies of coronene molecule and its adducts. The calculated electronic properties included the total energy, Homo and Lumo energies, energy gap Eg, ionization energy IE, electron affinity EA, electronegativity Χ, electronic softness S, are investigated by employing the B3LYP density functional theory with 6-31G basis sets. The calculations are carried out using Gaussian 09 package of programs. The obtained geometrical parameters from the relaxation of the structures studied showed that the coronene and its adducts are remain aromatic molecules. The results showed the gap of energy is decrease with increasing the number of hydroxyl sub groups added to the coronene. The hexa-hydroxyl coronene has the lowest value of energy gap and it has semiconducting properties. Addition of OH groups reduced IE and increased EA to coronene molecule Hexa-hydroxyl coronene has the smallest value of IE, all hydroxyl coronene molecules group have electronegativity less than that for coronene molecule, the electrochemical hardness of all studied molecules is smaller than that found in the coronene. The increasing of electronic softness corresponds to the decreasing in the electrochemical hardness Mono-hydroxyl coronene molecul has higher dipole moment (1.6615Debye) in comparison with the others. the hydroxyl groups added to the original molecule leads to increase the average polarizability and cause more reactivity of the molecule. Mono-hydroxyl coronene and di-hydroxyl coronene molecules have average dipole polarizability equal to value (268.362 and 274.324) a.u, penta-hydroxyl coronene and hexa-hydroxyl coronene has the highest polarizability and has highest reactivity. The map of ESP distribution showed that it is drag towards the hydroxyl groups due to presence the oxygen atoms of high electronegativity.