Synthesis, growth, characterization and quantum chemical investigations of a promising organic nonlinear optical material: Thiourea-glutaric acid

Synthesis of hydrazone-based polyhydroquinoline derivatives - antibacterial activities, α-glucosidase inhibitory capability, and DFT study

In recent years, polyhydroquinolines have gained much attention due to their widespread applications in medicine, agriculture, industry, etc. Here, we synthesized a series of novel hydrazone-based polyhydroquinoline derivatives via multi-step reactions. These molecules were characterized by modern spectroscopic techniques (1H-NMR, 13C NMR, and LC-HRMS) and their antibacterial and in vitro α-glucosidase inhibitory activities were assessed. Compound 8 was found to be the most active inhibitor against Listeria monocytogenes NCTC 5348, Bacillus subtilis IM 622, Brevibacillus brevis, and Bacillus subtilis ATCC 6337 with a zone of inhibition of 15.3 ± 0.01, 13.2 ± 0.2, 13.1 ± 0.1, and 12.6 ± 0.3 mm, respectively. Likewise, compound 8 also exhibited the most potent inhibitory potential for α-glucosidase (IC50 = 5.31 ± 0.25 μM) in vitro, followed by compounds 10 (IC50 = 6.70 ± 0.38 μM), and 12 (IC50 = 6.51 ± 0.37 μM). Furthermore, molecular docking and DFT analysis of these compounds showed good agreement with experimental work and the nonlinear optical properties calculated here indicate that these compounds are good candidates for nonlinear optics.

Comprehensive quantum chemical study of the associative complex of para-aminobenzoic acid and 7-diethylamino 4-methyl coumarin by adsorption and aromatic bridges

CONTEXT

The present study accounts for the quantum chemical and nonlinear optical properties of the combination of para-aminobenzoic acid and 7-diethylamino 4-methyl coumarin. Three different complexes were designed, surface interaction (adsorption) and two by connecting both molecules with π-bridge benzene and biphenyl. The amino and carboxyl groups were observed to behave as strong donor and acceptor sites in all the complexes. The band gap of the adsorbed complex was found more suitable. The absorption wavelength and intensity both were seen to increase with the increase in the number of benzene rings in the π-bridge. The values of first- and second-order hyperpolarizability suggest the improved nonlinear optical responses of the introduced complexes. Additionally, the negative value of second-order hyperpolarizability suggests the possibility of the occurrence of reverse saturable absorption in these combinations. The reported work gives theoretical insights into the nonlinear optical properties of the combination of para-aminobenzoic acid and 7-diethylamino 4-methyl coumarin.

METHODS

The molecular modeling and the quantum chemical studies were performed with Gaussian software packages. The standard B3LYP-6-311++G(d,p) basis functionals were used for energy minimization and other spectral calculations. All the surface analyses reported here are obtained by employing Multiwfn software. The chemical reactivity was established by the global reactivity descriptors. The intramolecular interactions and charge localization were stated using inter-fragment charge transfer analysis.

Growth, studies of milled and irradiated crystalline samples of DBNT for macro-photonic and electro-mechano functionalities

Single crystals of organic type of NLO crystalline material of DBNT - 8, 9-Dimethoxybenzo[b]naphtho [2,3-d] thiophene are proceeded to be grown by slow evaporation procedure and milled to micro scale and irradiated of Co-60 source of 100 Gy, 500 Gy and 5000 Gy for better scope of classification of system of the monoclinic type of DBNT-pure, micro and irradiated ones. The hardness study specifies the reverse indentation size effect (RISE) with work hardening coefficient above two of all DBNT specimen leads to the micro-tribological workings for springs with proper elastic parameters; the transmittance of DBNT of 5 specimens are 321 nm, 323 nm, 341 nm, 351 nm, and 352 nm for macro, micro, 100 Gy, 500 Gy, 5000 Gy. The photonic utility of identity for 3.86 eV and is 3.8629 eV by the transmittance data. The Non Linear Optical - NLO component this of 1.9, 1.94, 1.95, 1.96, 1.99 times that of KDP from which phase matching provision is enabled the influx property for the DBNT specimens is in the order of microns the (110) and (111) indexing represent for display device configuration. The dielectric behaviour of DBNT shows that polarization properly enabled for all categories by electrical performance, the abnormal variation is due to the vacancies created in the molecule by irradiation.

Study of nonlinear optical responses of phytochemicals of Clitoria ternatea by quantum mechanical approach and investigation of their anti-Alzheimer activity with in silico approach

Clitoria ternatea is a flowering plant with promising medicinal plants with a wide variety of active phytochemicals. The present study aimed at the computational investigation of the nonlinear optical (NLO) responses of the active phytochemicals of the Clitoria ternatea. The computational investigation of the NLO features was done by using the density functional theory (DFT) by B3LYP/6-311G + + (d, p) basis set. The structural parameters, mulliken charge distribution, and molecular electrostatic potential (MEP) surface clearly show the intramolecular charge transfer within Clitorin. The NLO properties were identified by computing the polarizability parameters. As the plant has high medicinal characteristics, the inhibiting properties of its phytochemicals were also investigated to combat Alzheimer disease (AD). The systematic in silico study identifies Clitorin as the most active and inhibiting phytochemicals of the plant. The results obtained from molecular dynamics (MD) simulation tell the stability of the complex and make it a fair selection as a drug-like molecule against AD. The cardio-toxicity analysis done for the Clitorin molecule verifies that it is harmless for the heart.

Supplementary information

The online version contains supplementary material available at 10.1007/s11224-022-01981-5.