ABSTRACT We report a theoretical study about
the effects of the thiophene and 1, 3, 4-oxadiazol groups on five organic
molecules with help of DFT and TD-DFT calculations. By using DFT/B3LYP/6-31G(d,
p) to investigate the electronic structures and related properties for studied
compounds in ground state, which can be found that the alkyloxy group has no
effect on the HOMO-LUMO gap. The lower LUMO energy for BBN2 and BBN2F2 or
larger electron affinity (EA), which are also favorable for hole transport. The
higher HOMO energy for BHT2 and BBT2Br4 or smaller ionization potential (IP),
which are also favorable for electron transport. The maps of electrostatic
potential (MEP) for the fives diodes, is discussed in term of colors change and
ligand groups presence, reactivity indices, showed for BBN2 and BBN2F2 as a
strong electrophile. The AIM analysis reveals bonds in compounds belong to
closed-shell type interactions, and another side, we used TD-DFT/B3LYP,
CPCM/TD-DFT-B3LYP in gas and solvent phase respectively as a quantum methods to
investigated the Photophysical properties in excited for thiophene and 1, 3,
4-oxadiazol ligand, absence of solvatochromism in all absorptions spectra. To
achieve deep blue emission, with increasing 1, 3, 4-oxadiazol group and
achieved the hypsochromic shift. The thiophene group shows the reverse and
emits red color.
KEY WORDS: OLED, Reactivity index,
Topological analysis, MEP, DFT and TD-DFT