Structural and ultrafast third-order nonlinearities of methyl and methoxy substituted anthracene chalcones: Z-scan, four-wave mixing, and DFT approaches

We report on the structural, thermal, linear, and ultrafast third-order nonlinear optical (NLO) properties of two novel anthracene chalcones: (2E)-1-(anthracen-9-yl)-3-(5-methylthiophen-2-yl)prop-2-en-1-one (5ML2SANC) and (2E)-1-(9-anthryl)-3-(2,4,5-trimethoxyphenyl)prop-2-en-1-one (245TMANC). The chalcones were synthesized by Claisen-Schmidt condensation reaction, and the single crystals were grown by the solvent evaporation method. The molecular structure was confirmed by FTIR and NMR spectroscopy, while the crystal structure was determined using the single crystal XRD. Both crystals belong to centrosymmetric monoclinic crystal system with space group P21/n. The Hirshfeld surface was analyzed to understand intermolecular interactions, and the band structures - including HOMO-LUMO levels, excited state energies, GCRDs and MEPs-were studied using DFT. The ultrafast third-order NLO properties were investigated by Z-scan and degenerate four-wave mixing (DFWM) techniques using Ti: Sapphire amplifier laser delivering ∼50 fs pulses at 800 nm (1 kHz, ∼4 mJ, 2 W). Two-photon absorption, positive nonlinear refraction, optical limiting and optical switching behaviors were observed by Z-scan measurements. The time-resolved DFWM show that the decay time of 5ML2SANC is ∼127 fs, while for 245TMANC it is ∼142 fs. The second hyperpolarizability (γ) measured by Z-scan, DFWM and the estimations from the DFT theory are found to be in good agreement (∼10-34 esu). The ultrafast optical response, significant NLO properties and thermal stability of the synthesized chalcones demonstrate their potential suitability in optical limiting and switching applications.

Multifaceted Study of a Y-Shaped Pyrimidine Compound: Assessing Structural Properties, Docking Interactions, and Third-Order Nonlinear Optics

In this study, we report the synthesis of a new compound, N4,N4-dimethyl-2-(methylsulfanyl)-N6-(4-phenoxyphenyl)pyrimidine-4,6-diamine (DMS), and its comprehensive analysis through structural and spectroscopic characterizations, reactivity parameters, and nonlinear optical properties, utilizing a combination of experimental and computational techniques. The experimental aspect of the investigation encompassed structural characterization using X-ray diffraction and spectroscopic assessments employing Fourier-transform infrared, Raman, and nuclear magnetic resonance techniques, along with thermal analysis. Our computational approach involved density functional theory (DFT) calculations and molecular dynamics (MD) simulations to examine the local reactivity properties of DMS. We employed fundamental reactivity descriptors to evaluate DMS's local reactivity and utilized MD simulations to identify DMS atoms engaging in significant interactions with water molecules. We conducted periodic DFT calculations on DMS's crystal structure to investigate the contributions of specific atoms and groups to the compound's overall stability as well as to analyze noncovalent interactions between DMS molecules. We assessed the nonlinear optical properties through dynamic second hyperpolarizability and third-order nonlinear susceptibility calculations. Additionally, we conducted a comparative analysis of the static and dynamic second hyperpolarizability for the DMS molecule within the sum-over-states framework. The obtained value for the third-order nonlinear susceptibility, (λ = 1907 nm), exceeds those of other organic materials reported in previous studies, indicating that the DMS crystal holds promise as a nonlinear optical material for potential application in photonic device fabrication. Furthermore, molecular docking studies were performed with the 3E5A, 4EUT, and 4EUU proteins, yielding binding affinities of -8.1, -8.2, and -8.3 kcal/mol, respectively, in association with the ligand.

Unraveling the structure-property relationship of a chalcone-based push-pull molecule for optical limiting application in high-powered laser

In this work, the optical limiting response of a highly π-conjugated push-pull chalcone derivative (2E)-3-(2,3-dimethoxyphenyl)-1-(3-nitrophenyl)prop-2-en-1-one (abbreviated as 3DPNP) has been investigated. The structure-property relationship of 3DPNP was explored through spectroscopic investigation and quantum chemical computations. The existence of weak-non-covalent interactions and charge transfer species that responsible for the chemical stability of 3DPNP were studied by AIM and NBO analyses. The quantitative and qualitative analysis of vibrational and electronic contribution to non-linear optical (NLO) response of 3DPNP were discussed in detail. The normal vibrational modes associated with a change in the dipole moment, polarizability, first- and second-order hyperpolarizabilities of 3DPNP were identified using DFT calculations followed by potential energy distribution (PED) analysis using Gaussian 09 W software and Gar2ped program, respectively. The changes in the NLO parameters with respect to the varying frequencies and electric dipole fields were studied. The abrupt changes in the NLO properties were noticed when the frequency doubled, confirming the second harmonic generation (SHG) efficiency of 3DPNP. From the non-linear absorption and refraction studies through the z-scan experiment, the optical limiting threshold value of 3DPNP is determined to be 3.26 kJ/cm2, which shows the suitability of the material for optical limiting applications in the continuous wave (CW) laser regime.

Crystal structure of (E)-1-(2–nitrophenyl)-3-phenylprop-2-en-1-one, C15H11NO3

C15H11NO3, P21/c (no. 14), a = 5.4092(2) Å, b = 23.9605(8) Å, c = 9.4887(3) Å, β = 96.080(1)°, V = 1222.89(7) Å3, Z = 4, R gt(F) = 0.0358, wR ref(F 2) = 0.0888, T = 173(2) K.

Structural and theoretical study of copper(ii) complex incorporating chalcone and 2,2′-bipyridine mixed ligands: a probable candidate for optical material

We report the synthesis, structural and photophysical data for a Cu(ii) complex, [Cu(L·bpy)(NO3)], with mixed chalcone and 2,2′-bipyridine ligands. Calculations are used to consider prospective applications in optoelectronic devices.

Synthesis and structural studies on (E)-3-(2,6-difluorophenyl)-1-(4-fluorophenyl)prop-2-en-1-one: a promising nonlinear optical material

A new fluorinated chalcone (E)-3-(2,6-difluorophenyl)-1-(4-fluorophenyl)prop-2-en-1-one was synthesized in 90% yield and crystallized by a slow evaporation technique. Its full structural characterization and purity were determined by scanning electron microscopy, infrared spectroscopy, gas chromatography-mass spectrometry, 1H, 13C and 19F nuclear magnetic resonance, thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), Raman microspectroscopy, UV-Vis absorption spectroscopy, single crystal X-ray diffraction (XRD) and Hirshfeld surface (HS) analysis. The fluorinated chalcone crystallized in centrosymmetric space group P21/c stabilized by the C-H⋯O and C-H⋯F interactions and the π⋯π contact. The crystalline environment was simulated through the supermolecule approach where a bulk with 378 000 atoms was built. The electric parameters were calculated at the DFT/CAM-B3LYP/6-311++G(d,p) level as function of the electric field frequency. The macroscopic parameters such as linear refractive index and third-order nonlinear susceptibility (χ (3)) were calculated, and the results were compared with experimental data obtained from the literature. The χ (3)-value for the chalcone crystal is 369.294 × 10-22 m2 V-2, higher than those obtained from a few similar types of molecule, showing that the chalcone crystal can be considered as a nonlinear optical material. Also, molecular theoretical calculations such as infrared spectrum assignments, frontier molecular orbital analysis and MEP were implemented, revealing that the most positive region is around the hydrogen atoms of the aromatic rings, and electrophilic attack occurs on the carbonyl group.

A molecular tailoring approach – a new guide to quantify the energy of push–pull effects: a case study on (E)-3-(1H-pyrrol-2-yl)prop-2-enones

We report a new approach to quantify the push–pull effect in molecules with internal charge transfer.

Y-shaped potential third-order nonlinear optical material – 3-(2-amino-2-oxoethyl)-5-methyl hexanoic acid: an analysis of structural, spectroscopic and docking studies

The merit of this work is that it has clearly established the structure and the nonlinear optical properties relationship of the title molecule and it could be helpful for developing new nonlinear optical materials.

Using the Supermolecule Approach To Predict the Nonlinear Optics Potential of a Novel Asymmetric Azine

Organic molecules with electron acceptors or withdrawal substituents terminal at π-conjugated system are promising candidates to be explored as materials with high linear and nonlinear optical properties. On the basis of these features, a novel asymmetric azine ( 7E, 8E)-2-(3-methoxy-4-hydroxy-benzylidene)-1-(4-nitrobenzylidene)hydrazineC₁₅H₁₃N₃O₄ (NMZ) was synthesized. The molecular structure of NMZ was elucidated by X-ray crystallography and the supramolecular arrangement was analyzed from Hirshfeld surface methodology. An iterative electrostatic scheme using a super molecule approach, where neighboring molecules are represented by charge points, was employed to investigate optical dipole moment (μ), the linear polarization (α) and the first (β) and second (γ) hyperpolarizabilities. The NMZ crystallized in the centrosymetric space group P2₁/n and packs via combined O-H···O, C-H···O, and N···π interactions. The macroscopic property of third order χ⁽³⁾ found for the NMZ is 298.62 times greater than values reported for chalcone derivative (2 E)-1-(3-bromophenyl)-3-[4 (methylsulfanyl)phenyl]prop-2-en-1-one. The results for NMZ indicate a good nonlinear optical effect.

Crystal growth and characterization of second- and third-order nonlinear optical chalcone derivative: (2E)-3-(5-bromo-2-thienyl)-1-(4-nitrophenyl)prop-2-en-1-one

Experimental and computational studies of linear and nonlinear optical (NLO) properties of (2E)-3-(5-bromo-2-thienyl)-1-(4-nitrophenyl)prop-2-en-1-one (5B2SNC) single crystals are reported. Good-quality and large-sized single crystals of 5B2SNC were successfully grown and characterized by powder X-ray diffraction and high-resolution X-ray diffractometry techniques. 5B2SNC was found to crystallize in the monoclinic noncentrosymmetric space group Cc and possesses moderately good crystalline perfection. The linear optical properties were investigated using the absorption spectrum, which reveals a direct optical band gap of 3.1 eV. The thermal stability was studied with thermogravimetric analysis/differential thermal analysis. The powder second harmonic generation efficiency was evaluated by the Kurtz and Perry method, and 5B2SNC was found to be 26 times more efficient than urea standard. Third-order NLO properties were studied by the z-scan technique with a femtosecond laser. The second hyperpolarizability was obtained to be ∼1.45 × 10−31 e.s.u. The molecule reveals a strong reverse saturation absorption and negative nonlinear refraction. The molecule exhibited good optical limiting properties, and its limiting threshold was measured to be ∼3.2 mJ cm−2. In addition, static electric dipole moments, linear polarizabilities, and first- and second-order hyperpolarizabilities were calculated by density functional theory (DFT). Highest occupied molecular orbital/lowest unoccupied molecular orbital band gaps were also evaluated by DFT calculations. The experimental and theoretical results showed that 5B2SNC exhibits excellent second- and third-order nonlinear optical properties.

Synthesis and Evaluation of Antiplasmodial Activity of 2,2,2-Trifluoroethoxychalcones and 2-Fluoroethoxy Chalcones against Plasmodium falciparum in Culture

A new class of compounds comprising two series of chalcones with 2,2,2-trifluoroethoxy group and 2-fluoroethoxy groups were synthesized and screened for in vitro antiplasmodial activity against Plasmodium falciparum (3D7) using the [³H] hypoxanthine incorporation inhibition assay. Chalcones with 2,2,2-trifluoroethoxy groups substituted on the p- and m-positions of the 1-phenyl ring showed weak antiplasmodial activity, while compounds substituted on the o-position of the 1-phenyl ring displayed enhanced antiplasmodial activity, thus indicating that 2,2,2-trifluoroethoxy groups on the 1-phenyl ring of chalcones show position-dependent antiplasmodial activity. Of the 34 compounds synthesized, chalcones 3a and 3f exhibited significant inhibitory effects, with IC₅₀ values of 3.0 μg/mL and 2.2 μg/mL, respectively. Moreover, these compounds 3a and 3f showed profound antiplasmodial activity in combination with artemisinin in vitro. The most active molecules, 3a, and 3f, were further assessed for their cytotoxicity towards mammalian Vero cells and the selectivity index (SI) values are 8.6, and 8.2 respectively, being considered non-toxic. We also studied the antiplasmodial activity of 2-fluoroethoxychalcones to discern the effect of the number of fluorine atoms in the fluoroethoxy group. Our results showed that chalcones with 2-fluoroethoxy group on the 1-phenyl ring exhibited more enhanced inhibitory effects on the growth of parasites than their trifluoro analogues, which reveals that monofluoroethoxy group is generally more effective than trifluoroethoxy group in the inhibition of parasite growth. Thus o-2,2,2-trifluoroethoxychalcones (Series 3) and 2-fluoroethoxychalcones may serve as good antiplasmodial candidates for future further development.

The solid state structure and environmental polarization effect of a novel asymmetric azine

Extensive solid state characterization of a novel asymmetric azine and its environmental polarization effect is reported.