Electronic Absorption Spectra and Third-Order Nonlinear Optical Property of Dinaphtho[2,3-b:2’,3’-d]Thiophene-5,7,12,13- Tetraone (DNTTRA) and Its Phenyldiazenyl Derivatives: DFT Calculations

Abstract

Third-order nonlinear optical (NLO) materials have broad application prospects in high-density data storage, optical computer, modern laser technology, and other high-tech industries. The structures and frequencies of Dinaphtho[2,3-b:2',3'-d]thiophene-5,7,12,13-tetraone (DNTTRA) and its 36 derivatives containing azobenzene were calculated by using density functional theory B3LYP and M06-2X methods at 6-311++g(d, p) level, respectively. Besides, the atomic charges of natural bond orbitals (NBO) were analyzed. The frontier orbitals and electron absorption spectra of A-G5 molecule were calculated by TD-DFT (TD-B3LYP/6-311++g(d, p) and TD-M06-2X/6-311++g(d, p)). The NLO properties were calculated by effective finite field FF method and self-compiled program. The results show that 36 molecules of these six series are D-π-A-π-D structures. The third-order NLO coefficients γ (second-order hyperpolarizability) of the D series molecules are the largest among the six series, reaching 10 7 atomic units (10 −33 esu) of order of magnitude, showing good third-order NLO properties. Last, the third-order NLO properties of the azobenzene ring can be improved by introducing strong electron donor groups (e.g.-N(CH 3) 2 or-NHCH 3) in the azobenzene ring, so that the third-order NLO materials with good performance can be obtained.

Exohedral Adsorption of N-(4-Methoxybenzylidene) Isonicotinohydrazone Molecule onto X12N12 Nanocages (where X=B and Al) and the Effect on Its NLO Properties by DFT and TD-DFT

“…In recent years, the search for nonlinear optical (NLO) materials for applications in the feld of modern laser technology, photonics, optical transmission, switching, sensing and computing, electronics and optoelectronics, and telecommunication is on a constant upsurge [1][2][3]. Teoretical and experimental studies reveal that boron nitride (BN) and aluminum nitride (AlN) nanocages are excellent adsorbents and are generally used in optoelectronics [4][5][6][7][8].…”