Germanium-based superatom clusters as excess electron compounds with significant static and dynamic NLO response; a DFT study

Herein, the geometric, electronic, and nonlinear optical properties of excess electron zintl clusters Ge5AM3, Ge9AM5, and Ge10AM3 (AM = Li, Na, and K) are investigated.

Boosted Electronic, NLO and Absorption Characteristics for Quercetin and Taxifolin; Comparative Experimental and DFT Studies

In the present study, a considerable, reproducible, and eco-friendly biological synthesis of Ag nanoparticles using Mangifera indica leaf extract as a reductant is documented. The spectroscopic characteristics of synthesized Ag nanoparticles are described by both UV-Vis and FT-IR techniques. The bandgap offsets, reactivity, and NLO properties for two flavonoids, quercetin, and taxifolin, are examined using the DFT approach. Also, a detailed comparative analysis for HOMO-LUMO interactions among quercetin and taxifolin is discussed. Results show that quercetin and taxifolin possess dipole moment (DM=4.79, 3.99 Debye) and bandgap offset (2.59, 2.98 eV). Both molecules are promising candidates as window layers for solar cells and memory switch devices. In addition, hyperpolarizability calculations show that quercetin NLO response is higher than taxifolin, which sets a revolutionary recall for NLO manufacture upgrade. Moreover, NBO and UV-Vis absorption characteristics are reported as well.

Boosted Electronic, NLO and Absorption Characteristics for Quercetin and Taxifolin: Comparative Experimental and DFT Studies

In the present study, a considerable, reproducible, and eco-friendly biological synthesis of Ag nanoparticles using Mangifera indica leaf extract as a reductant is documented. The spectroscopic characteristics of synthesized Ag nanoparticles are described by both UV-Vis and FT-IR techniques. The bandgap offsets, reactivity, and NLO properties for two flavonoids, quercetin, and taxifolin, are examined using the DFT approach. Also, a detailed comparative analysis for HOMO-LUMO interactions among quercetin and taxifolin is discussed. Results show that quercetin and taxifolin possess dipole moment (DM=4.79, 3.99 Debye) and bandgap offset (2.59, 2.98 eV). Both molecules are promising candidates as window layers for solar cells and memory switch devices. In addition, hyperpolarizability calculations show that quercetin NLO response is higher than taxifolin, which sets a revolutionary recall for NLO manufacture upgrade. Moreover, NBO and UV-Vis absorption characteristics are reported as well.

N-Arylation of Protected and Unprotected 5-Bromo 2-Aminobenzimidazole as Organic Material: Non-Linear Optical (NLO) Properties and Structural Feature Determination through Computational Approach

The interest in the NLO response of organic compounds is growing rapidly, due to the ease of synthesis, availability, and low loss. Here, in this study, Cu(II)-catalyzed selective N-arylation of 2-aminobenzoimidazoles derivatives were achieved in the presence of different bases Et3N/TMEDA, solvents DCM/MeOH/H2O, and various aryl boronic acids under open atmospheric conditions. Two different copper-catalyzed pathways were selected for N-arylation in the presence of active nucleophilic sites, providing a unique tool for the preparation of NLO materials, C-NH (aryl) derivatives of 2-aminobenzoimidazoles with protection and without protection of NH2 group. In addition to NMR analysis, all synthesized derivatives (1a–1f and 2a–2f) of 5-bromo 2-amino benzimidazole (1) were computed for their non-linear optical (NLO) properties and reactivity descriptor parameters. Frontier molecular orbital (FMO) analysis was performed to get information about the electronic properties and reactivity of synthesized compounds.

Exploration of Nonlinear Optical Enhancement and Interesting Optical Behavior with Pyrene Moiety as the Conjugated Donor and Efficient Modification in Acceptor Moieties

Herein, a series of new pyrene based hexylcyanoacetate derivatives (HPPC1-HPPC8) with A–π–D–π–D configuration were designed by end-capped modeling of non-fullerene acceptors on the structure of reference compound named dihexyl 3,3'-(pyrene-1,6-diylbis(4,1-phenylene))(2E,2'E)-bis(2-cyanoacrylate) HPPCR. Quantum chemical calculations of HPPCR and HPPC1-HPPC8 were accomplished at M06/6-31G(d, p) level. The stability of molecules due to the strongest hyper conjugative interactions in HPPCR and HPPC1-HPPC8 was estimated through NBO study. Interestingly, HOMO-LUMO band-gap of HPPC1-HPPC8 was found smaller than HPPCR which resulted in large NLO response. Among all the investigated compounds HPPC7 showed the larger NLO response due to the presence of four cyanide (CN) groups which strengthens the bridge conjugation, and its band gap was found to be 2.11eV, smaller as compared to band gap of HPPCR (3.225 eV). The absorption spectra of HPPC1-HPPC8 compounds showed maximum absorption wavelengths (483–707 nm) than HPPCR (471.764nm). The designed compounds showed high NLO response than HPPCR. Amazingly, highest amplitude of linear polarizability < α>, first hyperpolarizability (βtotal) and second hyperpolarizability < γ > for HPPC7 were achieved to be 1331.191, 200112.2 and 4.131 ×107 (a.u), respectively. NLO response showed that the HPPC1-HPPC8 might be potential candidates for NLO applications.

Exploration of Nonlinear Optical Properties of Triphenylamine-Dicyanovinylene Coexisting Donor-π-Acceptor Architecture by the Modification of π-Conjugated Linker

High-tech electronic, optics, and storage devices require organic compounds with nonlinear optical (NLO) properties. This study designed D-π-A based dyes with donor triphenylamine (TPA) and acceptor dicyanovinylene (DCV) species by structurally modifying π-conjugated linkers. Our density functional theory (DFT) computations analyzed the impact of structural variations on the nonlinear optical (NLO) response of newly designed dyes. The B3LYP/6-31G(d,p) level determined the quantic chemical insights: frontier molecular orbital (FMOs), natural bond orbitals (NBOs), and nonlinear optical (NLO) properties of the designed dyes (DPTM-1 to DPTM-12). UV-Vis analysis based on the TD-DFT/CAM-B3LYP/6-311+G(d,p) level explored the optoelectronic properties. DPTM-1 and DPTM-5 showed the highest red-shifted absorption band at 519 and 506 nm. NBO analysis shows that DPTM-1 to DPTM-12 dyes have positive values for all donors (D) and π-spacers but negative values for acceptors (A). The π-spacers act as a conveyer between donor and acceptor moieties; thus, electrons were transferred smoothly from D to A units, which resulted in a charge separation state. Our calculations show the extent of NLO response in terms of electronic transitions, polarizability &lt;α&gt;, and first hyperpolarizability (β) values. The highest value of βtotal was 110,509.23 a.u. manifested in DPTM-6 due to 2,5-dimethyloxazole as a second π-linker, twice that of R (66,275.95 a.u.). Also, DPTM-6 and DPTM-8 exhibit the lowest energy band gap of 2.06 and 2.04 eV, respectively. In short, all DPTM-1 to DPTM-12 dyes manifested maximum absorption, lowest energy band gap, greater charge transfer from donor to the acceptor, and better first hyperpolarizability values as compared to the R and showed good NLO response. The present work represents new compounds with remarkable NLO properties and their applications in modern high-tech devices.

Structural modulation of π-conjugated linkers in D–π–A dyes based on triphenylamine dicyanovinylene framework to explore the NLO properties

A donor–π–acceptor type series of Triphenylamine–dicyanovinylene-based chromophores ( DPMN1–DPMN11 ) was designed theoretically by the structural tailoring of π-linkers of experimentally synthesized molecules DTTh and DTTz to exploit changes in the optical properties and their nonlinear optical materials (NLO) behaviour. Density functional theory (DFT) computations were employed to understand the electronic structures, absorption spectra, charge transfer phenomena and the influence of these structural modifications on NLO properties. Interestingly, all investigated chromophores exhibited lower band gap (2.22–2.60 eV) with broad absorption spectra in the visible region, reflecting the remarkable NLO response. Furthermore, natural bond orbital (NBO) findings revealed a strong push–pull mechanism in DPMN1–DPMN11 as donor and π-conjugates exhibited positive, while all acceptors showed negative values. Examination of electronic transitions from donor to acceptor moieties via π-conjugated linkers revealed greater linear (〈 α 〉 = 526.536–641.756 a.u.) and nonlinear ( β tot = 51 313.8–314 412.661 a.u.) response. It was noted that the chromophores containing imidazole in the second p-linker expressed greater hyperpolarizability when compared with the ones containing pyrrole. This study reveals that by controlling the type of π-spacers, interesting metal-free NLO materials can be designed, which can be valuable for the hi-tech NLO applications.