Mohammad Hossein Fekri - Department of Chemistry, Ayatollah Borujerdi University, Borujerd, Iran.
Niko Karimpoor - Department of Chemistry, Ayatollah Borujerdi University, Borujerd, Iran.
Motaleb Ghasemian - Department of Chemistry, Ayatollah Borujerdi University, Borujerd, Iran.
Samaneh Soleymani - Department of Chemistry, Ayatollah Borujerdi University, Borujerd, Iran.
Maryam Razavi Mehr - Department of Chemistry, Ayatollah Borujerdi University, Borujerd, Iran.

The structure geometry, vibrational frequencies, electronic and optical properties of a series of donor-acceptor substituted dodecadehydrotribenzo [۱۸] annulenes ([۱۸] DBA) were investigated using the B۳LYP method at a ۶-۳۱+G (d, p) basis set. After optimization of the structures, HOMO and LUMO energies, gap energy (Eg), global hardness (η), chemical potential (μ), electrophilicity index (ω), maximum charge transfer (∆Nmax), electronegativity (χ), Fermi level (EFL), wavelength (λ), oscillator power (f۰), and participation percentage (% Con) for [۱۸] DBA derivatives. A significant increase in the first hyperpolarizability was observed by substitution on [۱۸] DBA. The results of this study may be used to design and construct materials with adjustable electrical properties. The results indicate that the NLO response of [۱۸] DBA could be enhanced by functionalizing different substitutions. In general, the NLO response and electronic properties of the S۱-۱۰ are more excellent than others.

annulene, Nonlinear optical property, Electronic property, Hyperpolarizability