NLO Materials Research Articles

A potent synthesis and supramolecular synthon hierarchy percipience of (E)-Nʹ-(Napthalen-1-yl-methylene)-benzenesulfonohydrazide and 1-Napthaldehyde: A combined experimental and DFT studies

An adduct of (E)-Nʹ-(Napthalen-1-yl-methylene)-benzenesulfonohydrazide (NMBSH) and 1-naphthaldehyde (NAH) was synthesized using an uncomplicated condensation procedure from the NAH and benzenesulfonylhydrazine (BSH) in a good yield (71.0%) and this was crystallized in EtOH. The adduct compound was characterized using spectroscopic techniques such as 1H NMR, 13C NMR, FT-IR and UV–Vis. Structure of adduct was established by using a single crystal X-ray diffraction method (SC-XRDM). The crystallographic parameters are a = 11.87(2)Å, b = 6.75(8)Å and c = 15.87(2)Å, β = 109.62(2)° and it was resolved in monoclinic crystal system and Pc space group. The molecules undergo hydrogen bonding interaction and π-π interaction in the crystal structure of compound. In order to understand the structural and electronic properties, computational calculations of NMBSH and NAH were carried out. All computational based calculations were performed using the DFT at B3LYP (Becke, 3 parameters, Lee-Yang-Parr) theory with 6-31+G (d,p) basis set. Natural bond orbitals (NBOs) analysis was computed at B3LYP/6-311+G (d,p) method. UV-VIS analysis was conducted by TD-DFT/B3LYP/6-31+G (d,p) level. A good agreement was obtained between the experimental and the computational structural data of NMBSH and NAH. The second order perturbation energies have been obtained by NBO analysis, confirmed interactions and strengthen in the intriguing architectures of NMBSH and NAH. With the help of DFT approach, HOMO-LUMO energies were figured out to obtain electronic insights into the NMBSH and NAH. Moreover, information regarding local as well as global chemical activity, nucleophilic and electrophilic nature of NMBSH and NAH has been obtained. Moreover, an excellent agreement was found between experimental and computational UV-VIS findings. The obtained NLO results indicated that our adduct as NMBSH and NAH displayed stronger response than reference molecule. It could be concluded that this study might be helpful for NLO materials.

The structure-property studies and mechanism of optical limiting action of methyl 4-((4-aminophenyl)ethynyl)benzoate crystal under continuous wave laser excitation

This study focuses on the design of the new dye of donor-π-acceptor (D−π−A) system of methyl 4-((4-aminophenyl)ethynyl)benzoate (MAPEB) to highlight its structural-property relation through a combined experimental and quantum chemical calculation approaches for optical limiting applications. MAPEB was synthesized via aerobic condition palladium-catalysed Sonogashira cross-coupling reaction with good yield. This molecular structure was confirmed by single crystal X-ray crystallographic analysis and the crystal exhibits monoclinic non-centrosymmetric space group of Pc. The existence of intermolecular interactions was confirmed by Hirshfeld analysis, showing high contribution of C⋯H contact which suggested the high nonlinear optical response of the compound. The experimental spectroscopic data including Fourier Transform Infrared (FT-IR), 1H and 13C Nuclear Magnetic Resonance, electronic absorption spectra, HOMO-LUMO energy gap were compared with Density Functional Theory (DFT) at 6–311++G (d,p) basis set. The experimental results complement the theoretical findings in supporting anticipated electronic properties of the molecule. Additionally, the z-scan analysis unveils an excellent value of χ3 of MAPEB in the order of 10−6 esu which indicate good nonlinear optical material under 532 nm continuous wave laser. Low optical limiting action was measured at 110 kW/cm2 which is suitable for various continuous wave laser applications. These findings prove that MAPEB has the potential to be employed as NLO materials for photonic applications.

Synthesis, Spectral techniques, X-ray Crystal structure, DFT method, Hirshfeld surface analysis and Molecular docking studies of 1-(furan-2-yl)methyl)-4,5-diphenyl-2-(p-tolyl)-1H-imidazole

• Novel synthesis of 1-(furan-2-yl)methyl)-4,5-diphenyl-2-(p-tolyl)-1 H -imidazole. • New compound are effectively characterized by spectral techniques. • Single crystal X-ray crystallographic and Hirshfeld surface analysis have been discussed. • MEP, NLO, NBO and Thermodynamic properties have been discussed. • Molecular docking studies were carried out with antibacterial and anticancer proteins. We have synthesized a novel 1-(furan-2-yl)methyl)-4,5-diphenyl-2-p-tolyl-1H-imidazole (FMDI) molecule. The structure of these compound were confirmed by IR, 1 H and 13 C NMR spectral techniques. The compound was also confirmed by single crystal XRD. The geometry of the synthesized compound were examined by density functional theory (DFT) method at B3LYP/6-31G (d, p) level of theory. The optimized geometrical parameters obtained by DFT calculation are in good agreement with single crystal XRD data. The stability and charge delocalization of the molecule were also studied by natural bond orbital (NBO) analysis. The HOMO–LUMO energies describe the charge transfer takes place within the molecule. Molecular Electrostatic Potential map (MEP) was studied for predicting the reactive sites. The reported FMDI molecule used as a potential NLO material since it has high µβ 0 value. Thermodynamic parameter like entropy, enthalpy and heat capacity are calculated and these values are increased with increasing the temperature due to the enhancement of vibrational intensities. The anti-bacterial and anti-cancer activities of these compound were studied using molecular docking studies. The molecular docking results revealed that the FMDI compound exhibit more binding energies -11.69kcal/mol and 15.40kcal/mol when compared to the standard drug Ciprofloxacin and Mitomycin.

Synthesis, spectral characterization, DFT, docking studies and cytotoxic evaluation of 1-(4-fluorobenzyl)-2,4,5-triphenyl-1H-imidazole derivatives

Abstract In this present study, a novel series of 1-(4-fluorobenzyl)-2,4,5-triphenyl-1H-imidazole derivatives (2a-d) have been synthesized and characterized by elemental, FT-IR, 1H, 13C NMR and LC-Mass spectral techniques. The compound (2a) confirmed by Single-crystal X-ray diffraction. The single-crystal XRD data were in excellent agreement with DFT calculations obtained by optimized geometrical parameters. The HOMO-LUMO energy gap calculations predict energy along with their overlapping of an atomic orbital. The structure is described as the cause as possible NLO material since it has a high µβ0 value. The anticancer activities of compounds (2a–d) were analyzed using docking studies and it is compared with their experimental results. The imidazoles (2a–d) with 3ERT protein have also been evaluated the binding methods and interaction patterns of the docking studies. The compounds (2a–d) of the anticancer activities were tested as opposed to the cell line MCF-7 human breast cancer. The imidazoles showed outstanding cytotoxicity towards cancer cells.

Ultrafast photophysical and nonlinear optical properties of novel free base and axially substituted phosphorus (V) corroles

The progression in synthetic procedures over the last two decades gave admittance to a wide variety of corroles for suitable potential applications such as photovoltaics, photonics, and bio-imaging. In this communication, we present results from our investigations of ultrafast photophysical processes and third-order nonlinear optical properties of newly synthesized donor-acceptor based free-base [(C6F5)3] and phosphorus [P-(OH)2(C6F5)3] corroles. The global analysis of the femtosecond transient absorption data based on the compartmental model revealed the corresponding time constants of several photophysical processes such as (a) internal conversion (τIC) in the 260–280 fs range (b) vibrational relaxation (τVR) in the 2.5-5 ps range and (c) nonradiative relaxation times (τnr) in the 4.15–7.6 ns range and finally (d) triplet lifetimes in the range of 25–50 μs. The two-photon absorption (TPA) cross-section measurements were performed using the femtosecond, kHz pulse Z-Scan technique at 600 nm and 800 nm and the retrieved TPA cross-section values were in the range of ~102 GM. Degenerate four-wave mixing measurements illustrated a large third-order nonlinear optical susceptibility χ(3) with a magnitude of 6.9 × 10−14 esu and instantaneous (sub-picosecond) response, suggesting a pure electronic contribution to the nonlinearity of these corroles. The discoveries from this study may help further to extend the capability of corroles as NLO materials for photonic applications.

Adamanzane based alkaline earthides with excellent nonlinear optical response and ultraviolet transparency

Strategies to design alkalides with excellent NLO responses are well established in the literature. On the contrary, alkaline earthides are quite scarce mainly because of low electron affinities of alkaline earth elements. Herein, we report two series of alkaline earthides M+(26Adz)M- (M+ = Li and Na; M- = Be, Mg and Ca), based on 26Adz as a complexant and alkali metals as sources of electrons for alkaline earth metals. These complexes are characterized as alkaline earthides by negatives charges on alkaline earth metals (NBO analysis) and presence of polarized-p HOMO orbital on alkaline earth meals. Presence of HOMO on alkaline earth metals is also confirmed through PDOS spectra. HOMO-LUMO gaps of the compounds are reduced significantly and range from 2.15 to 2.85 eV as compared to 5.17 eV HOMO-LUMO gap of pure cage. Besides H-L gaps, these compounds possess remarkably large nonlinear optical responses with the first hyperpolarizabilities (βo) up to 1.0 × 106 au for Na +(26Adz)Mg-. The nonlinear optical response of alkaline earthides is superior than those of alkalides and it is attributed to the presence of excess electron on alkaline earth metals in polarized p-orbitals. The hyperpolarizabilities are rationalized through two level method. The projection of hyperpolarizability on the dipole moment, βvec for both series are comparable to βo (static first hyperpolarizability) which indicate that the charge transfer is parallel to the molecular dipole moments. The alkaline earthides possess very small transition energies (ΔE) ranging from 0.6 to 2.4 eV. The UV–Vis analysis reveals that these alkaline earthides are transparent in ultraviolet region of the electromagnetic spectrum. The designed alkaline earthides are potential candidates for UV-transparent high performance NLO materials for applications in optical communication, optical computing and other laser devices. Present results will certainly inspire experimentalists and theoreticians to design and synthesize other alkaline earthides-based NLO materials with even better performance.

Structural, spectroscopic, physical properties and quantum chemical investigation on bromide salt of 4-dimethylaminopyridine NLO material for optoelectronic applications

In this paper, investigations on the crystal structure, vibrational, physical properties on charge transfer single crystals of 4-dimethylaminopyridinium bromide. Its structural parameters, vibrational, mechanical and optical properties have been studied by SCXRD, FT-IR, FT-Raman, Vickers microhardness test and Ultraviolet–Visible spectral analysis. The computational investigations were carried out to determine the molecular geometries, vibrational modes, HOMO-LUMO analysis, population analysis, MEP, thermodynamics and macroscopic NLO response of the compound. The theoretical and experimental molecular geometrical parameters and vibrational assignments have been in good agreement. Mulliken charge distribution of the present compound was studied systematically. The chemical hardness, electro-negativity and chemical potential of the molecule have been computed by HOMO - LUMO plot. FMO analysis indicates the electron delocalization on the title compound and also its low value of energy gap indicates electron transfer. NLO parameters were calculated by HF and DFT methods. The calculated hyperpolarizability values showed that the compound is a good candidate for NLO applications.

LiBa4Ga5Q12 (Q = S, Se): Noncentrosymmetric Metal Chalcogenides with a Cesium Chloride Topological Structure Displaying a Remarkable Laser Damage Threshold.

The exploration of novel infrared nonlinear optical (IR NLO) materials with large second-harmonic generation (SHG) responses and wide band gaps has become very imperative recently. Herein we reported two noncentrosymmetric compounds, LiBa4Ga5Q12 (Q = S, Se), crystallizing in space group P421c (No. 114), which feature 3D frameworks built by a basic [Ga5Q16]17- windmill cluster and LiQ4 tetrahedra in a cesium chloride topological structure. Both compounds satisfy the desired balance between good SHG responses (∼1.5× that of AgGaS2) and wide band gaps (3.43 and 2.44 eV) with remarkable laser damage thresholds (21× and 6× that of AgGaS2). The theoretical calculations uncover that the [Ga5Q16]17- cluster makes major contributions to the SHG effect in LiBa4Ga5Q12. In addition, the structure-performance relationship among all compounds in the I-II4-III5-VI12 system has been discussed systematically, which indicates that the introduction of the alkali metal lithium in the I site is beneficial for the production of large band gaps. This work will be helpful in exploring novel IR NLO materials with special structures and comprehensive properties in the chalcogenide system.

Preparation, characterization and study on the nonlinear optical parameters of novel biphenyl-4-carbohydrazide derivative

We report here the preparation, characterization and the 3rd order nonlinear optical properties of (N-[(E)-(3-Nitrophenyl) methylidene]) biphenyl-4-carbohydrazide, a novel organic NLO material. The characterization of the compound for molecular structural study was carried out by FTIR and X-ray Diffraction. A Photoluminescence and UV–vis spectrum was selected to study the linear optical properties. In dimethyl formamide (DMF) solution, the 3rd order NLO properties have been measured at 532 nm by DPSS continuous wave laser using the Z-scan technique. Open aperture data indicates the presence of two photon absorption (TPA) at 532 nm. The measured experimental values of nonlinear absorption coefficient (β) is 10-8 (cmW−1), the nonlinear refractive index(n2) is 10-11(cm2W−1), and third order susceptibility (χ(3)) is 10-9esu. Due to TPA at 532 nm the compound shows good optical limiting behavior. The values obtained are comparable with the values obtained for 4- methoxy chalcone derivatives and dibenzylidene acetone derivatives. The optical limiting threshold of the compound is 2.8 KJ/cm2 .The comparatively high value obtained indicates that this material may be used in optical device applications like optical limiters and optical switches.

Influence of superalkali oxides on structural, electrical and optical properties of C24 fullerene nanocluster: A theoretical study

The influence of superalkali oxides on structural, electrical and the optical properties of 6-5 isomer of C24 fullerene nanocluster was investigate using DFT calculations. It was shown that the structure of fullerene was drastically affected by adsorption of M3O on its surface and as a result of all bonding lengths, was subsequently changed. DOS results showed that the Eg of C24 in presence of M3O (M=Li, Na, K) was fairly changed so that the electronic properties and electrical conductance of C24 were not affected by M3O adsorption. Based on the results of NBO calculations, specifically on MEP surfaces and HOMO-LUMO distribution, the charge was transferred from M3O to C24 fullerene; therefore, the M3O is the positive head of complexes and in an electric field it is oriented toward the negative pole. The calculated polarisability(α) and the first hyperpolarisability(β0) values indicated that the adsorption of M3O on exterior surface of C24 fullerene has had a drastic effect on the optical response of C24 fullerene and caused a large increase in α and β0 values. TD-DFT calculations were also carried out in order to confirm the β0 values. This work theoretically devises novel C24-based nanostructures via interaction with Superalkali Oxides in order to promote, their potential applications in electronic devices and high-performance NLO materials.

Synthesis, crystal structure, spectroscopic and nonlinear optical properties of organic salt: A combined experimental and theoretical study

The 2-methoxy-pyrido[1,2-a]quinoxalin-11-ylium bromide (2MPQYB) crystal was characterized from single crystal X-ray diffraction (SCXRD) and spectroscopy analysis. The fluorescence spectrum of the compound showed one broad peak at 473 nm. The supramolecular arrangement in solid state was confirmed by 2D-fingerprint plots and Hirshfeld surface analysis. An additional topological analysis from quantum theory of atoms in molecules (QTAIM) highlights the observed halogen bonds on solid state for 2MPQYB. Also the supermolecule (SM) approach was used to simulate the crystalline environment with 246,064 atoms and an ab-initio calculation method, which includes the Density Functional Theory (DFT) at CAM-B3LYP/6–311++G(d,p) level, was used to estimate the crystal linear refractive index and the third-order nonlinear susceptibility at the frequency of ω=0.086a.u. (λ = 532 nm) and the obtained values were 1.85 and χ3=621.14×10−22m2/V2 respectively. This χ3-value is up to 312.13 times greater than obtained for others organic crystals of the literature, thus indicating that the 2MPQYB can be considered for various applications of NLO materials.

Effect of optical, mechanical and thermal properties of bio-organic chlorophyll-a of Ficus religiosa added ADP optical single crystal: A Novel NLO material

A 0.5 mol% of organic Chlorophyll-a of Ficus religiosa and inorganic ammonium dihydrogen phosphate are added to an aqueous solution to form a semi-organic Chl-a doped ADP (CHLAADP) single crystal, grown by slow evaporation method. CHLAADP is subjected to linear optical, nonlinear optical, mechanical and thermal studies. UV–vis-NIR is taken for analyzing and to identify the optical properties, in terms of the cutoff wavelength, band gap, refractive index, optical conductivity, extinction coefficient, and electrical conductivity of CHLAADP crystal. It is observed that the inclusion of Chl-a enhance the optical properties of ADP. Vickers microhardness analysis establishes that CHLAADP belongs to the soft material category, The Optical parameter analysis confirmed that, CHLAADP is preferred for optoelectronics applications. The organic material (Chl-a) doped ADP may also be applied in communications systems, optical computing and healthcare applications like medical imaging process under Photonics. In the current work, the researcher has adopted the innovative idea of organic(Chl-a) doped inorganic (ADP) to study the optical characteristics of dopant materials in terms of optical and electrical conductivity, its response to light and temperature have been fulfilled. These properties are found to be suitable for sensors, power grids, electronics and lenses. The study and results for the parameters of CHLAADP prove that it is suitable for optoelectronic applications.

Zinc Phthalocyanine-Poly (Vinyl Alcohol) nanocomposite films: Low threshold optical limiting properties based on third-order nonlinear absorption response

In this article, we discuss on an in-depth study of the structure and morphology as well as optical (linear/nonlinear) properties of Zinc Phthalocyanine (ZnPc) - Poly (Vinyl Alcohol) (PVA) nanocomposite films. An investigation into the third-order nonlinear absorption properties of the nanocomposite films of ZnPc-PVA system, on excitation with low power continuous wave (CW) laser light at 632.8 nm, for different concentrations of the ZnPc content and at different input intensities, is presented. In these nanocomposites, a transition from Saturable Absorption (SA) to Reverse Saturable Absorption (RSA) was observed, on either increasing fluence or ZnPc content. The estimated values of the effective coefficients of nonlinear absorption (β) and imaginary third-order nonlinear susceptibility (Imχ(3)) are better than those reported ones. Furthermore, the optical limiting action of these samples is demonstrated. The results suggest that the nanoclustered organic chromophores are dispersed uniformly in the voids/free volumes available between the PVA chains. Standing on these points, it may be noted that the newly fabricated ZnPc-PVA nanocomposite films, which possess excellent surface homogeneity, high laser damage threshold, improved thermal and photostability, and prolonged lifespan (five years or more!), represent an efficient low threshold NLO material with significant potential applications in optoelectronic and photonic devices.

Synthesis, Crystal Structure, and Nonlinear Optical Properties of Zn(II) Complex with 4,4',4''-Tri-tert-Butyl-2,2':6',2''-Terpyridine: A Dual Exploration

The metal complexes are getting immense importance as hi-tech functional materials. In the present investigation, a new Zn(II) complex [Zn(C27H35N3)Cl2] (1) has been synthesized by using 4,4′,4″-tri-tert-butyl-2,2′:6′,2″-terpyridine ligand. The synthesized compound 1 is characterized by X-ray crystallography, IR spectroscopy as well as elemental analysis. The X-rays structure revealed that compound 1 crystallizes in trigonal space group P3221 in which Zn(II) atom is penta coordinated having highly distorted trigonal bipyramidal geometry. The compound 1 has a 2-fold rotational axis parallel to the b axis, which is passing through two opposite N and C atoms in the central pyridine ring, and the Zn atom. Moreover, quantum computational study has been performed to get insights into the optical and nonlinear optical response properties of compound 1. The geometrical structure of compound 1 has been optimized with M06-2X functional and LANL2DZ/6-311G** basis set and it shows good resemblance with the experimental coordinates. The linear polarizabilities including isotropic (αiso) and anisotropic (αaniso) polarizability amplitudes are found to be 69.44 × 10−24 and 34.99 × 10−24 esu, respectively. Similarly, the NLO polarizability (❬γ❭) amplitude for compound 1 is found to be 104.19 × 10–36 esu at M06-2X method, which is ~5 times greater than the p-NA (a model NLO molecule). Additionally, frontier molecular orbitals, molecular electrostatic potentials and Hirshfeld analysis are used to explore the structure-property relationship of compound 1. Thus, the indigenously synthesized compound 1 might be a reasonable candidate for its possible applications as optical and NLO material.

Pb6O5(NO3)2: A Nonlinear Optical Oxynitrate Structurally Based on Lead Oxide Framework.

A high second harmonic generation response is demonstrated by a Pb6O5(NO3)2 lead oxynitrate whose identity was verified upon reinvestigation of the PbO-Pb(NO3)2 system. Its crystal structure exhibits a unique cationic [Pb6O5]2+ framework hosting orientationally ordered NO3- triangles in the channels. Easy preparation and high thermal stability (until ∼500 °C in air) suggest it to be a new promising NLO material.

Density Functional Theory Investigation of Nonlinear Optical Properties of T-Graphene Quantum Dots.

Using density functional theory calculations, we have analyzed nonlinear optical properties of a series of T-graphene quantum dots differing in their shape and size. Electronic polarizability and first-order and second-order hyperpolarizability of these systems are investigated and shed light on their stability and electronic properties. Negative cohesive energy shows that they are energetically stable. The effect of size and incident frequency on their nonlinear responses are comprehensively discussed. Most of the systems exhibit a strong NLO response, and it is enhanced in the presence of an external field. All these systems show absorption maximum ranging from UV to visible window. Overall, this theoretical framework highlighted the nonlinear optical properties of T-graphene quantum dots that may provide valuable information in designing potential NLO materials.

CsBP2O6(OH)2: a second-order NLO material with a unique borophosphate anionic partial structure and strong SHG effect.

A noncentrosymmetric (NCS) alkali-metal borophosphate CsBP2O6(OH)2 (CBPO) containing a unique borophosphate anionic partial structure has been obtained through a mixed-solvent thermal method. Its structure could be regarded as a 1-D chain that is built by Cs+ cations and a unique anionic chain [BP2O6(OH)2]∞n- composed of BO4 and PO3(OH) groups. CBPO possesses a wide UV-vis transparent range and shows a strong SHG response. Moreover, we have well explored and established the origin of the SHG effect by dipole moment and PDOS calculations. This work will help inspire and stimulate scientists to discover more such excellent NLO materials.

An unprecedented planar π-conjugated [B2P5]5- group with ultra-large birefringence and nonlinearity: an ab initio study.

Searching for new nonlinear optical active (NLO-active) units would greatly promote the development of NLO materials. Herein, we theoretically investigate a newly reported [B2P5]5- group which consisted of two corner-sharing [BP3]3- trigonal planar units. Attributed to the coplanar π-conjugated configuration and the unique connection mode, the [B2P5]5- group can achieve both the largest birefringence (Δn∼ 0.68) and nonlinearity (d15∼ 57.14 pm V-1) among all inorganic planar NLO-active groups, which makes it a good NLO-active unit. Our analysis also reveals that the modulation of the electronegativity of constituent elements upon replacing with the elements in the same period can effectively improve the NLO responses, which would inspire a new direction for designing high performing NLO materials.

Second-order nonlinear optical materials with a benzene-like conjugated π system.

Second-order nonlinear optical (NLO) materials that can alter the wavelength of lasers have attracted significant attention for their optoelectronic applications. Recent research suggests that benzene-like structure units, such as [B3O6] and [C3N3O3] rings, are promising building units to construct new NLO materials with excellent optical properties. In this feature article, we will introduce the recent development of benzene-like ring based NLO materials with a highlight of our contributions, illustrating how to optimize the conjugated π system, including arrangement modes, different linkers, and isoelectronic species, to tune the band gap and NLO properties.

Coordinated regulation on critical physiochemical performances activated from mixed tetrahedral anionic ligands in new series of Sr6A4M4S16 (A = Ag, Cu; M = Ge, Sn) nonlinear optical materials

A new family of non-centrosymmetric (NCS) compounds Sr6A4M4S16 (A = Ag, Cu; M = Ge, Sn) with mixed tetrahedral anionic ligands (AS4 and MS4) was successfully synthesized and characterized for the first time. All of the compounds exhibit excellent performances as promising infrared nonlinear optical (IR NLO) materials, with large NLO responses (1.1-2.0 × benchmark AgGaS2), high laser damage thresholds (2.0-4.5 × AgGaS2) and wide IR transmission ranges, and are nonhygroscopic. Moreover, their property modulation by the combination of different anionic groups was also discussed.