First-order Hyperpolarizability Values Research Articles

Enhanced nonlinear optical and optical limiting responses of 7-diethylamino-4-methyl coumarin functionalized with silver nanoparticles: A combined experimental and DFT study

The present study accounts for the enhanced nonlinear optical and optical limiting activity of 7-diethylamino-4-methyl coumarin (7DMC) after the addition of silver nanoparticles. The theoretical calculations were done one three different solvents water, methanol, and dimethyl formamide (DMF), and on the basis of the band gap, methanol was selected as the most suitable solvent. Further, the liquid samples were prepared in methanol. The natural bond orbitals show the active participation of the lone pairs of electrons of 2O and 35Ag as donor and acceptor moieties respectively. The values of first-order hyperpolarizability of the 7DMC+Ag3 combination were raised to 2002.71 × 10−30 esu, 778.72 × 10−30 esu, and 677.12 × 10−30 esu in water, methanol, and DMF. The valley-like structure in the Z-Scan spectra indicated the occurrence of reverse saturable absorption in the prepared samples. The optical limiting threshold of the 7DMC+AgNps was decreased from that of the probe 7DMC and AgNps indicating the early attenuation of the optical limiting nature of the combination. Thus, the overall results validated the enhanced optical nonlinearity of the combination. Moreover, it can be stated that the proposed nanoparticles combination has potential candidature to be used for the fabrication of laser safety devices and eye aids.

Impact of doping with organic dopants and mixed doping with alkali metals and organic dopants on the absorption, electronic, optoelectronic, thermodynamic and nonlinear optical properties of dibenzo[b,def]chrysene in gaseous media: DFT and TD-DFT studies.

In this study, we evaluate the geometrical, absorption, optoelectronic, electronic, nonlinear optical (NLO) and thermodynamic properties of dibenzo[b,def]chrysene molecule derivatives by means of DFT and TD-DFT simulations. In view of the aim of producing new high-performance materials for non-linear optics (NLO) by doping test, two types of doping were used. We obtained six derivatives by doping with organic dopants (Nitro, amide and ticyanoethenyl) and mixed alkali metal (potassium) and organic dopants. Doping with organic dopants produced molecules A, B and C, respectively when substituting one hydrogen with nitro (NO2), amide (CONH2) and tricyanoethenyl (C5N3) groups, while mixed doping involved considering A, B and C and then substituting two hydrogens with two potassiums to obtain compounds D, E and F respectively. The negative values of the various interaction energies calculated for all the doped molecules show that they are all stable, but also that molecules C and F are the most stable in the case of both dopings. The gap energies calculated at the B3LYP level of theory are all below 3eV, which means that all the molecules obtained are semiconductors. Better still, compounds C and F, with gap energies of 1.852eV and 1.204eV, respectively, corresponding to decreases of 35.67% and 58.18% in gap energy compared with the pristine molecule, are more reactive than the other doped molecules. Mixed doping is therefore a highly effective way of narrowing the energy gap and boosting the semiconducting character and reactivity of organic materials. Optoelectronic properties have also been improved, with refractive index values higher than those of the reference material, glass. This shows that our compounds could be used under very high electric field conditions of the order of 4.164 109V.m-1 for C and 7.410 109V.m-1 for F the highest values at the B3LYP level of theory. The maximum first-order hyperpolarizability values for both types of doping are obtained at the CAM-B3LYP level of theory by C: 10-30esu and by F: 10-30esu, and second-order values are also given by these same compounds. These values are higher than the reference value, which is urea, making our compounds potential candidates for high-performance NLO applications. In dynamic mode and at a frequency of 1064nm, at the CAM-B3LYP level of theory, the highest dynamic hyperpolarizability coefficients were obtained by C and F. Hyper-Rayleigh scattering , coefficients of the electro-optical Pockel effect (EOPE), EFISHG, third-order NLO-response degree four-wave mixing , quadratic nonlinear refractive index n2 were also calculated. The maximum values of n2 are obtained by C (6.13 10-20 m2/W) and F (6.60 10-20 m2/W), these values are 2.24 times higher than that of fused silica which is the reference for degenerate four-wave mixing so our molecules could also have applications in optoelectronics as wavelength converters, optical pulse modulators and optical switches. Using the DFT method, we were able to determine the optimized and stable electronic structures of doped dibenzo[b,def]chrysene derivatives in the gas phase. We limited ourselves to using the proven B3LYP and CAMB3LYP levels of theory for calculating electronic properties, and non-linear optics with the 6-311G + + (d,p) basis set, which is a large basis set frequently used for these types of compound. Gaussian 09 software was used to run our calculations, and Gauss View 6.0.16 was used to visualize the output files. TD-DFT was also used to determine absorption properties at the B3LYP level of theory, using the same basis set.

Molecular structure, optical, first-order hyper polarizability, electronic properties, reactivity (ELF and LOL) − computational analysis using DFT and Multiwfn for 2, 3-diaminopyridinium selenate

A detailed study on the first principle calculations of 2,3-diaminopyridinium selenite (2,3-DAPS) – an organometallic salt has been performed using B3LYP/6–311++G(d,p). Single crystal X-ray diffraction (XRD) analysis confirms that the crystal formed exhibits a monoclinic crystal structure, specifically belonging to the centrosymmetric space group P21/c. The obtained primitives and interfacial angles are as follows: a = 7.4978(15)Å, b = 7.6681(15) Å, c = 14.314(3) Å, α = γ = 90°, β = 93.75(3)°, and the volume of the unit cell V = 821.2(3) (Å)3. The structure was optimized with a global minimum. The natural bonding orbital charge transfer studies between the cation and anion was performed to gain insights into their electronic interactions. Energy gap and other global chemical reactivity descriptors have been computed with the aid of molecular orbital studies. The influence of solvent on the absorption spectra provided the evidence of solvent–solute interactions and their impact on the electronic transitions within the molecule. The presence of electrophilic and nucleophilic reactivity in the chemical is indicated by the molecular electrostatic potential (MEP) map. From the nonlinear optical (NLO) studies, it has been found that the first-order hyperpolarizability value is 30.771 × 10−31 esu, which is 8.252 times that of urea. This suggests that the compound may be a better non-linear optical material and suitable for laser applications. To calculate the proportion of intermolecular interactions and examine the distribution compound's electrostatic potential, a Hirshfeld surface analysis was conducted. The analysis provided insights into the spatial arrangement of molecules and their interactions. Additionally, topology path calculations elucidated the intrinsic connectivity between critical points, shedding light on the bonding characteristics within the compound. The likelihood of electron density at bonding and anti-bonding sites was also determined using the Electron Localization Function (ELF) and Localised Orbital Locator (LOL) plots. These analyses aided in understanding the electron distribution and the nature of chemical bonding within the compound, providing valuable information about its electronic structure and reactivity.

Synthesis, Theoretical studies, and antibacterial activity of Novel Zn(II) metal complex with salicylaldehyde semicarbazone, and ortho phenylene diamine ligands.

Computational and experimental investigation of synthesized Zn(II) complex. Salicylaldehyde semicarbazone (SSC) and ortho phenylene diamine (OPDA) were the ligands for the preparation of Zn(II) metal complex. Using quantum chemistry simulations at DFT/B3LYP/LANL2DZ level of theory. FT-IR, UV, and Mass spectrometry methods were characterized the complex. The computed small gap energy demonstrated that the Zn(II) molecule had good biological activity. Measured dipole moment and first-order hyperpolarizability values were useful to investigate the complex NLO activity. Intra-molecular charge transfer, donor-acceptor transitions, and stabilization energies were determined by analyzing natural bond orbital (NBO) and Mulliken charges. Electrophilic and nucleophilic interactions were performed with the MEP map. QTAIM framework explained the nature of different intermolecular interactions within the molecule. Moreover, the ADMET studies of Zn(II) compound were also analyzed. The title molecule showed good antibacterial activity.

Utilization of methyclothiazide adsorbed with malonamide for quantum chemical applications: A DFT and DFT-D2/D3 studies

Herein, cost-effective and reliable predictions were made for the optical and electronic properties of the combination of methyclothiazide and melonamide. Interactions between both the title molecules were computationally investigated. The combined structure of both molecules shows the occurrence of immense intramolecular charge transfer from melonamide toward methyclothiazide. Reduction in the band gap of the complex shows the stability of the complex. The combination of methyclothiazide and melonamide gave a red shift in the absorption wavelength to 250 nm. The higher Fourier transform infrared modes corresponding to the -NH bonds of methyclothiazide suggest these groups are suitable adsorption sites for the physisorption of melonamide. The values of first-order hyperpolarizability of the complex were found to be increased to 413.11 au as compared to that of probe methyclothiazide (286.07 au) and melonamide (73.94 au). The observed escalation in the first-order hyperpolarizability shows the potential capability of the proposed combination to be used as strong nonlinear optical materials.

Nonlinear optical response of silver trimer adsorbed para-aminobenzoic acid: A DFT study

The reported study is motivated by our previously done experimental demonstration of the optical limiting behavior of para-aminobenzoic acid and enhanced nonlinear optical responses of compounds with Ag3 nanoparticle complex. The present study is a theoretical insight into the nonlinear optical responses of para-aminobenzoic acid adsorbed with Ag3 trimer. The enhancement in the optical nonlinearity of the para-aminobenzoic acid after the adsorption of the silver trimer (Ag3) was accounted in the present study. The density functional theory was used to establish the occurrence of the intra and intermolecular charge transfer between the donor and acceptor moieties of the para-aminobenzoic acid and Ag3 trimer. The molecular electrostatic potential surface and inter-fragment charge transfer analysis were used to establish the donor nature of the Ag3 trimer, amino group, and acceptor of the carboxyl group. The absorption spectra and Fourier-transform infrared spectra were used to account for the electronic and vibrational modes. The value of first-order hyperpolarizability of para-aminobenzoic acid and Ag3 complex was observed to increase by six times that of para-aminobenzoic acid. The high value of first-order hyperpolarizability shows the potential nonlinear optical activity of para-aminobenzoic acid adsorbed with Ag3 trimer. The presented study forms a strong base for experimental demonstration of the nonlinear optical activity of the PABA and the silver nanoparticles and the experimental work will be done in the near future for the NLO responses and optical limiting activity of PABA combined with silver nanoparticles.

Structure, Frontier Molecular Orbitals, MEP, Charge Analysis, and NLO Study of 2,4-, 2,5-, and 2,6-Dimethylanilines Using DFT

This study includes the evaluation of most stable structure, frontier molecular orbitals, molecular electrostatic potential (MEP), and nonlinear optical (NLO) parameters of 2,4-dimethylaniline (2,4DMA), 2,5-dimethylaniline (2,5DMA), and 2,6-dimethylaniline (2,6DMA) using density functional theory (DFT) employing B3LYP functional with 6-311++G(d,p) basis set. HOMO-LUMO energies, band gap energies, and global reactivity descriptors were obtained from the optimized structures. The band gap energy was determined as 3.7865, 3.9348, and 3.9443 eV for 2,4DMA, 25DMA, and 2,6DMA, respectively. The reactive sites of the molecules were obtained from the molecular electrostatic potential energy. The NLO parameters such as dipole moment, polarizability, and hyperpolarizability have been investigated for the title molecules. The investigated dipole moment and first-order hyperpolarizability values are higher than the prototypical value of urea and show good NLO behavior. The NMR chemical shifts, electronic absorption spectra, and charge distribution of atoms were calculated theoretically. Furthermore, thermodynamic and rotational constants were also calculated.

Reactivity and Structural Investigation of Tetrahydroneoprzewaquinone A as an Anti-Inflammatory Agent: An Experimental and Molecular Modeling Perspective

This intriguing study aimed to explore the reactivity and structural investigation of (3R,3′R)-2,2′,3,3′-tetrahydroneoprzewaquinone A (THNPQ A) as a potential anti-inflammatory agent. Substantially, the electronic properties were investigated using LanL2DZ, 6-311++G (d,p), and STO-3G basis sets, with electronegativity values of 7.9816, 6.3038, and 5.0166 eV, respectively. The natural bond orbital (NBO) analysis calculations of optimization energies revealed that LanL2DZ had the highest stabilization energy (526.65 kcal/mol) for the interaction between πC8-C9 and πC3-C4. Regarding nonlinear optical (NLO) properties, 6-311++G (d,p) exhibited the highest averaged polarizability and first-order hyperpolarizability values, while the polarizability anisotropies Δtotal followed the order 6-311++G (d,p) (65.2054 a.u.) > LanL2DZ (42.8782 a.u.) > STO-3G (29.9349 a.u.). Analysis of the density of states (DOS) and orbital contribution showed that 6-311++G (d,p) had the highest density peaks at both the highest occupied molecular orbital (HOMO) (–0.5 a.u.) and the lowest unoccupied molecular orbital (LUMO) (0.00 a.u.). The condensed dual descriptors indicated minimal variations in the f A – and f A + values, with an increase in Δf A, f A –, and f A + values following the order STO-3G > LanL2DZ > 6-311++G (d,p). The sites for potential nucleophilic attack were identified as O11, O12, O36, and O37, which exhibited the highest values with the STO-3G basis set. Empirical evidence from in vitro inhibition assays unequivocally validates the potent anti-inflammatory activity of THNPQ A. Particularly noteworthy is its exceptional binding affinity, surpassing that of diclofenac. By establishing conventional hydrogen bonds with the glycine of COX-I and histidine of COX-II, THNPQ A exhibits remarkable potential as an effective agent for combating inflammation. These findings boldly emphasize the promising therapeutic prospects of THNPQ A in the field of anti-inflammatory treatment, positioning it as a compelling candidate for further investigation and development.

Synthesis, spectral characterization, SC-XRD, Hirshfeld, DFT and in silico antidiabetic activity of novel imine (E)-N-(2-nitro benzylidene) naphthalene-1-amine, a newly synthesized imine: A theoretical and experimental evaluation

A novel imine compound, (E)-N-(2-nitrobenzylidene) naphthalene-1-amine (NBNA), has been successfully synthesized through the reaction of o-nitrobenzaldehyde and 1-naphthylamine. The structural characterization of NBNA has been carried out using single-crystal X-ray diffraction (SC-XRD) analysis. The XRD analysis reveals that NBNA crystallizes in a monoclinic crystal system with the space group P21/c. The unit cell parameters of NBNA are determined as follows: a = 7.549 (4) Å, b = 19.680 (11) Å, c = 9.598 (6) Å, β = 107.96(3)°, and Z = 4. Notably, the crystal structure of NBNA is stabilized by π-π stacking interactions between the naphthyl moiety and the nitrophenyl moiety, occurring at a perpendicular distance of 3.542 Å. Quantum mechanical calculations employing the B3LYP/6–311G(d,p) method in GAUSSIAN 09 software have been employed to determine the optimized geometry, molecular electrostatic potential (MEP), frontier molecular orbitals (FMO), Time-dependent Density Functional Theory (TD-DFT), and chemical reactivity descriptors of NBNA. The vibrational spectroscopic data has been compared with the DFT/B3LYP/6–311G(d,p) method and scaled using MOLVIB for analysis. By examining the NBOs, the distribution of electron density and the interaction between orbitals can be analysed, shedding light on the stability and reactivity of the compound. Additionally, frontier molecular orbital analysis and molecular electrostatic potential mapping are discussed to gain further insights. First-order hyperpolarizability studies have been conducted to explore the nonlinear optical behaviour of the molecule. By calculating and comparing the first-order hyperpolarizability of the compound with a reference molecule (in this case, urea), the obtained results indicate that the crystal of the molecule possesses a significantly higher first-order hyperpolarizability value (19.124 times urea) suggesting its potential as a promising material for nonlinear optical applications. An in-depth examination of the Hirshfeld surface and two-dimensional fingerprint plot has been conducted to gain insights into the intermolecular interactions of the compound. Molecular docking studies are performed on the PPARγ target to assess the molecule's potential antidiabetic activity, revealing a binding energy of -6.71 kJ/mol for NBNA with the target. The comprehensive assessment of the compound's ADMET properties provides valuable insights into its pharmacological potential and aids in the selection of promising drug candidates.

Density Functional Theory Study of the Effect of Mono-Halogen Substitution on Electronic and Non-Linear Optical Properties of Porphyrin

Porphyrin is an organic macrocycle compound, with a chemical formular (C20H14N4) it act as important components in various technological application like solar cell, due to their flexibility and low production cost. In this work, DFT and TD-DFT were used to investigate the molecular geometry, HOMO-LUMO energy gap, global chemical indices, thermodynamic properties, non-linear optical properties, IR frequencies and IR intensities, open circuit voltage and UV-Vis spectrum of parent and substituted porphyrin molecules were calculated and noted. All the computations were performed by using Gaussian 03 package. Our result for the bond lengths indicates that the strongest bond was found in chloroporphyrin molecule with value of 1.0771(Å) and the highest bond angles was found to be . The calculated value of HOMO-LUMO energy gap shows that porphyrin will be more stable by the substitution of fluoride atom with HOMO-LUMO energy gap of 5.5865eV. The value of energy gap for parent porphyrin molecule (2.8885) eV was found to be very closer to the reported value of (2.920) eV. It was found that the zero point vibrational energy reduces, while the entropy and specific heat capacity of the molecules rises, due to the effect of the substitutions. The non-linear optical properties calculations shows that, the first-order hyperpolarizability values turn out to be ten times than that of the prototype urea ( esu) molecule, which is commonly used for the comparison of NLO properties with other materials. The computed frequencies and intensities result shows that fluoroporphyrin has slightly higher peak values of frequencies with corresponding intensities than the rest of the substituted porphyrin molecules. The open circuit voltage ranges from 2.0206-4.1568eV in the case of high LUMO and 0.9465-3.0828eV in the case of low LUMO, this value can be applied to organic solar cell. The UV-VIS spectrum, shows that due to the solvent effect there was an increase in the excitation energy and then slight increase in oscillator strength. Our finding shows that the hybrid halogenated compound may be utilized as an application in sensor and solar cells.

Enhancing the reactivity, electronic, linear and non-linear optical properties of C45H15-like carbon nanocone doped with titanium dioxide, boron, and nitrogen: DFT and TD-DFT study

The density functional theory (DFT) levels B3LYP, B3PW91 and CAM-B3LYP/6–31+G(d) were used to systematically evaluate the reactivity, electronic, linear and non-linear optical (NLO) properties of the titanium dioxide, boron and nitrogen-doping C45H15-like carbon nanocone. Due to this doping, the |HOMO-LUMO| energy gap of the initial carbon nanocone (CO) has narrowed considerably and some values of the |HOMO-LUMO| gap energy of the derivatives formed are lower than 1 eV. This result shows that some of the derivatives may be used as suitable semiconductor materials and others as highly demanded-superconducting materials in the electronics industry. In addition, all these studied derivatives showed a red-shifted absorption maximum, however only the obtained derivative by substituting both five carbon atoms with five nitrogen atoms and ten carbon atoms with ten boron atoms (N5B10) exhibits the highest absorption capacity in the visible range, implying that the latter could be a promising candidate in photovoltaic devices. Finally, the first-order hyperpolarizability values of all the formed derivatives are largely superior to that of the pure carbon nanocone (CO) and also to that of the reference compound para-nitroaniline (p-NA), which leads us to say that these formed derivatives may be suitable candidates for NLO applications. Also, according to our investigations, the boron and nitrogen atom arrangements established within our studied carbon nanocone predict exothermic reactions in contrast to the data collected in the literature that predict endothermic reactions. Furthermore, with respect to dopant enhancements to our studied carbon nanocone, it should be noted that the simultaneous manipulation of the boron and nitrogen heteroatoms with a higher probability of boron presence than nitrogen offers new opportunities to improve the overall C5n 2H5n carbon nanocone properties with n ≥ 3.

Synthesis, Antifungal Evaluation of 3-[{(1-aminomethyl) -5,7-dimethyl-2- oxoindolin-3-ylidene} amino]-2-phenylquinazolin-4(3H)-ones and their NLO, MESP, Global Reactivity Descriptor, and AIM Study through DFT Approach

Abstract:A series of fused 3-[{(1-aminomethyl)-5,7-dimethyl-2-oxoindolin-3-ylidene}amino]-2- phenylquinazolin-4(3H)-ones 4(i-ix)) has been designed and synthesized by the condensation reaction between 3-amino -2-phenylquinazolin-4(3H)-one and 5,7-dimethylindolin-2,3-dione, followed by aminomethylation with secondary amines in the presence of formaldehyde and were also screened for their antifungal potential against human pathogenic fungi. The structures of all synthesized compounds have been established with the help of elemental and spectral analysis, such as NMR, FT-IR and mass spectrometry. Out of all synthesized compounds 4(i-ix), theoretical calculation was performed for 3-((5,7-dimethyl-1-(morpholinomethyl)-2-oxoindolin-3-ylidene)amino)-2-phenylquinazolin- 4(3H)-one (4i). The experimental 1H was compared with theoretically calculated values by using B3LYP/6-31G (d, p) level through the GIAO approach. The higher value of first-order hyper polarizability predicted (4i) may be used as NLO material. To explore molecular stability, three intermolecular interactions, such as N8—O22··· H47, C37—H64 ···N12, and C23—H45 ···C30, were observed through the QTAIM approach. In addition, global reactivity descriptor and molecular electrostatic potential were computed for the prediction of reactivity and reactive sites.

Crystal growth, structural and DFT study of novel single crystal (E)-N’-(2-chlorobenzylidene)-4-fluorobenzohydrazide for nonlinear optical applications

Nonlinear optical (NLO) material, (E)-N'-(2-chlorobenzylidene)-4-fluorobenzohydrazide (CBBH) novel single crystal was grown via a Schiff base chemical reaction. A single crystal X-ray diffraction technique was utilized for the recognition of the crystal structure of the CBBH. The imperfection of novel CBBH crystal was checked by high resolution X-ray diffraction (HRXRD) study. Hirshfeld surface study through colour coding was applied to know the intra and intermolecular force interactions. Fourier transforms infrared (FTIR), proton 1H and carbon 13C nuclear magnetic resonance (NMR) spectra were employed to elucidate the various functional groups and structure of the crystal. The absorption maxima from UV–Vis plot for the CBBH molecule was found at 314 nm, which reveals the π-π* transition. Photololuminescence (PL) study reveals that emission observed in the blue-violet region. The HOMO and LUMO energies were investigated using the density functional theory (DFT) method. Natural bond orbital (NBO) analysis explored the donor-acceptor exchanges and it's endurance into intra-molecularly. The first-order hyperpolarizability value, β0 = 23.73 × 1030 esu was observed for CBBH crystal, which is ∼64 times larger than that of urea molecule (0.3728 × 1030 esu). Z-scan experiment on CBBH crystal supports its third-order nonlinear optical (NLO) properties. Optical limiting analysis indicates reverse saturation absorption behavior of CBBH crystal.

The Nonlinear Optical Properties of Ferrocene-containing Metalloporphyrins Toward the Pico-second Laser

Background: The nonlinear optical properties of ferrocene-containing metalloporphyrins toward pico-second laser were studied using calculational and experimental methods, and the relationship between their structures and nonlinear absorption properties were discussed. Aims: The metal ions introduced into the porphyrin rings intensively affect the nonlinear optical properties. Methods: The nonlinear optical properties and the relationship between the property and the structure of the synthesized ferrocene-containing metalloporphyrins are studied using the calculational method and the open-aperture Z-scan technology for pico-second laser. Results: The Z-scan results show that Co-P-Fc, Zn-P-Fc and Pd-P-Fc exhibit reverse saturable absorption characteristics toward the laser with 532 nm wavelength and 21 ps pulse width, and the nonlinear absorption coefficients (β) of them were 4.1, 3.2 and 1.3 cm/GW, respectively, when the incident laser fluency at the focal point of the lens is 29 mJ/cm2. In addition, the values of β decrease with the increase of the incident laser fluency. These results indicate that the nonlinear absorption characteristics of Co-P-Fc, Zn-P-Fc and Pd-P-Fc are ascribed to the excited state absorption (ESA). However, Cu-PFc, Ni-P-Fc and P-Fc show saturated absorption characteristics toward the ps laser pulse. Conclusion: To elucidate the intrinsic factors that influence the nonlinear optical properties, the electronic distribution, flow of charge density during the transition from the ground state to the excited state, and the first-order hyperpolarizability values (β) are calculated using the time-dependent density functional theory (TD-DFT). The calculated results show that the molecular polarity and the change of the molecular polarity before and after the transition from HOMO to LUMO, which is dominated by the redox potentials of the introduced metal ions, are the most important factors that affect the nonlinear optical properties of the title compounds.

Experimental and theoretical studies of a thiourea derivative: 1-(4-chloro-benzoyl)-3-(2-trifluoromethyl-phenyl)thiourea

The 1-(4-chloro-benzoyl)-3-(2-trifluoromethyl-phenyl)thiourea compound was synthesized by a two-step reaction and a single crystal of it was obtained by recrystallization method. Its structure was elucidated by elemental analyzes, FT-IR, 1H NMR, and 13C NMR techniques, and its molecular and crystal structure was also determined by single-crystal X-ray diffraction analysis. The Hirshfeld surface analyzes of the crystal structure indicate that the most important contributions for crystal packing are from H···H (23.8%), H···S/S···H (14.5%), H···F/F···H (14.3%), C···H/H···C (14.2%), and Cl···F/F···Cl (9.0%). In addition, energy-framework calculations are used to analyze and visualize the three-dimensional topology of the crystal packing. The electrostatic energy framework is dominant over the dispersion energy framework. The density functional theory method with the basis set of B3LYP/6-311G(d,p) has been employed to obtain the optimized structural geometry, Mulliken charges, molecular electrostatic potential, frontier molecular orbitals, the total density of states, reduced density gradient analysis and natural bond orbitals. The experimental crystal structure parameters and optimized structure parameters are very similar. The HOMO–LUMO energy gap of the compound is 3.5307 eV. Different global chemical reactivity descriptor parameters were also calculated. Nonlinear optical properties such as anisotropy of polarizability, mean polarizability, static dipole moment, and first-order hyperpolarizability values were theoretically determined. The Fukui functions as electron density-based local reactivity descriptors were also calculated to explain the chemical selectivity or the reactivity site in the molecule. Molecular docking studies were also carried out to determine the inhibitory action of the title compound against the main protease (6LU7) of a new coronavirus (COVID-19).

Density Functional Theory Study of the Structural, Electronic, Non-Linear Optical and Thermodynamic Properties of Poly (3-Hexylthiophene-2, 5 - Diyl) in Gas Phase and in Some Solvents

Poly(3-hexylthiophene-2,5-diyl) (P3HT) and its derivatives are polymer based materials with π conjugation framework. P3HT is useful photoelectric material and can be used in organic semiconductor devices such as PLED, OLED, Nonlinear optical devices and solar cells. In this work, a theoretical study of P3HT in the gas phase and in some solvents (methanol, thiophene, chloroform, toluene, and acetone) were investigated and reported based on Density Functional Theory (DFT) as implemented in Gaussian 09 package using B3LYP/6-31++G (d, p) basis set. Structural properties such as bond lengths and bond angles as well as the HUMO, LUMO, energy gap, global chemical index, thermodynamic properties, NLO and DOS of the P3HT molecule in order to determine the reactivity and stability of the molecule were obtained. The results obtained showed that the solvents have effects on the structural, electronic and non-linear-optical properties of the molecule. The optimized bond length revealed that the molecule has a stronger bond in methanol with smallest bond length of about 1.0840Å (C28-H35) than in gas phase and the rest of the solvents. It was observed that the molecule is more stable in methanol with HOMO-LUMO energy gap and chemical hardness of 3.8338eV and 1.9169eV respectively. This indicates that the energy gap and chemical hardness of P3HT molecule increase with the increase in polarity and dielectric constants of the solvents. The energy gap obtained is compared with the one in literature \((3.10 \mathrm{eV})\). This indicates that the reported energy-gap leads by about \(0.7 \mathrm{eV}\). The calculations of thermodynamic properties indicate that P3HT molecule has the highest value of specific heat capacity \((\mathrm{CV})\), that is \(152.307 \mathrm{Cv}(\mathrm{Kcal} / \mathrm{Mol})\) in methanol, toluene has the highest value of entropy as \(266.960\) (Kcal/Mol), and thiophene has the highest value of zero-point vibrational energy (ZPVE) as \(455.37486 \mathrm{Kcal} / \mathrm{Mol}\). The NLO properties show that methanol has the highest value of total dipole moment ( \(\mu_{\text {tat }}\) ) as \(1.01764\) a u while acetone has the highest value of first order hyperpolarizability ( ( tot) as \(4.4447 \times 10^{-30}\) esu than the rest of the solvents. The values obtained for the first order hyperpolarizability for P3HT in acetone is about 12 times than that of the urea molecule, \(\left(0.3728 \times 10^{-30} \mathrm{esu}\right)\) which is commonly used for the comparison of NLO properties The results of the \(I R\) spectra show that the studied molecule was stable in both the gas phase and in solvents since no imaginary frequency was observed. It was also observed that the most intense frequency was found to be \(3024.9421 \mathrm{~cm}^{-1}\) at an intensity of \(140.2464 \mathrm{~km} / \mathrm{mol}\) in methanol and \(3088.6908\) \(\mathrm{cm}^{-1} at intensity of 77.6119 \mathrm{~km} / \mathrm{mol}\) in gas phase. The theoretical values of the open circuit voltage were found to be \(1.635 \mathrm{eV}, 1.614 \mathrm{eV}, 1.605 \mathrm{eV}, 1.576 \mathrm{eV}, 1514 \mathrm{eV}\), and \(1.445 \mathrm{eV}\) for methanol, toluene, acetone, chloroform, thiophene and the gas phase respectively. These changes in the properties of the molecule are observed due to the differences in the dielectric constants of the solvents. The results show that careful selection of the solvents can enhance the properties of the molecule for Organic solar cells (OSC)s applications.

Structural, spectral, DFT and Z-scan analysis of (E)-4-fluoro-N′(3,4,5-trimethoxybenzylidene)benzohydrazide for optoelectronics applications

ObjectiveTo synthesis a new Schiff base material (E)-4-fluoro-N′-(3,4,5-trimethoxybenzylidene)benzohydrazide (FBBH) by a slow evaporation method for nonlinear optical activity. MethodsSingle crystal X-ray diffraction (SCXRD), Fourier Transform Infrared (FTIR) spectroscopy, Nuclear magnetic resonance (NMR) spectroscopy, NBO analysis using DFT, third order non-linear optical (NLO) properties by Z-scan study. ResultsFrom NBO analysis, it is observed that the high energy ~ 197.82 kJ/mol transferred from donor N13→π*O16-C19 explores the hyperconjugation of –CONH– active group. The value of first-order hyperpolarizability ~ 23.73 × 10−30 esu was obtained for the FBBH compound which is 64 times greater than the reference molecule urea. The third order non-linear optical (NLO) properties of the FBBH molecule was evaluated from the Z-scan study. This study indicates that FBBH compound is one candididtae for optical limiters.

Quantum Mechanical Study of Three Aromatic Bioactive Fatty Alcohol Compounds with Nonlinear Optical and Potential Light Harvesting Properties

In the present work, Quantum mechanical properties of three different organic compounds [(2S)-1-(4-nitrophenyl) pyrrolidin-2-yl] methanol (NPPM), 2-(Methyl(4-nitrophenyl) nitro) ethanol (MNAE), and N, N-Bis (2-hydroxyethyl)-4-nitroaniline (HENA) were investigated by computational approach. The geometries were optimized to ground state using the density functional theory (DFT) with level B3LYP/6311-G (++d, p) basis set. The Mulliken charge distribution and molecular electrostatic potential (MEP) map of the title molecules shows the existence of huge charge distribution and the charge transfer within the molecules due to the presence of nucleophilic and electrophilic moieties. The vibrational spectra of the title molecules seem to have high intensity Raman modes. The UV–Vis spectra for the three molecules were found to indicate the presence of π-π* and n-π* electronic transitions between wavelength 300–500 nm. The computed value of first-order hyperpolarizability for the molecules were found to be higher than the reference materials. This validates the nonlinear optical responses of the title molecules. The light harvesting efficiency of the molecules were also determined. For the NPPM molecule, light harvesting efficiency of 64% was obtained. This validates the potential applications of NPPM in designing new photosensitizer solar cells.

Synthesis of second order nonlinear optical multichromophore based on double-donors with enhanced electro-optic coefficients and thermal stability

Our work was related to the systhesis of several nonlinear optical dendrimers L1-L3 with identical Bis(N,N-diethyl)aniline-derived donor bridge and phenyl-trifluoromethyl-tricyanofuran acceptor. The dendritic structure of multichromophores can effectively reduce the electrostatic interaction between chromophores. And the strong acceptor result in large first-order hyperpolarizability of the chromophores. Multichromophores L2-L3 showed very high poling efficiencies due to large steric hindrance and first-order hyperpolarizability value of chromophores. A large poling efficiency (2.10 ± 0.08 nm2/V2) and r33 (205 p.m./V) have been achieved for neat chromophore L3 thin films at 1310 nm. Besides, the glass transition temperature (Tg) of L2 and L3 has greatly improved to 125 °C and 133 °C, respectively. All of these provided an new insights into molecular design of chromophore with enchanced poling efficiency and high thermal stability.

Quantitative Structure-activity Relationship Studies and Nonlinear Optical Properties of 2-Phenylbenzofuran Derivatives: A Density Functional Theory Study

Density Functional Theory calculations, in the ground state of 2-Phenylbenzofuran, were carried out using the GGA-PBE, PBV86 and meta-GGA-TPSS hybrid functionals with 6-31G (d, p) as a basis set. First, theoretical calculations were performed using these functionals to obtain the stable conformer of the molecule. In addition, Mulliken population natural population and natural bond orbital analyses were calculated. The molecular electrostatic potential, band gap energies, global, local chemical reactivity descriptors and non-linear optical (NLO) properties were studied. Additionally, the NLO properties of 2-Phenylbenzofuran and those of its derivatives were investigated by GGA-PBE/6-31G (d,p) level of theory. The first-order hyperpolarizability value of all 2-Phenylbenzofuran derivatives was found within the range extending from 4.00 × 10-30 to 43.57 × 10-30 (esu). It indicated that they possess remarkable NLO properties. In addition, a multiple linear regression procedure was used to envisage the relationships between molecular descriptors and the activity of 2-Phenylbenzofuran derivatives; the quantitative structure-activity relationship (QSAR) studies were performed on them using quantum descriptors. The QSAR was applied to determine a correlation between the various physico-chemical parameters of the studied compounds and their biological activities. The statistical quality of the QSAR models was assessed using statistical parameters, i.e. R2, R2adj and R2cv.