Order NLO Research Articles

Crystal growth and physicochemical characterization of urea doped 4-methoxyaniline (U-4MOA) single crystals for NLO and antimicrobial applications

The single crystals of 4-methoxyaniline doped with urea (U-4MOA) were grown by slow evaporation method. The crystal structure of the U-4MOA was determined to be orthorombic using single-crystal X-ray diffraction (SXRD) investigation. The existence of functional groups was substantiated by FT-IR spectrum. The percentage of elements contained in the grown crystal was estimated using EDAX analysis. The surface studies by scanning electron microscopy reveals the formation of interlaced pattern in U-4MOA crystal. Thermal properties of U-4MOA were determined by TGA and DTA methods and it melts at 69°C. The UV-visible study discloses the transparency of the grown crystal throughout visible region. Fluorescence spectrum of U-4MOA shows an emission band at 663 nm. The mechanical properties of U-4MOA were determined from Vickers's hardness testing. The electrical properties of the U-4MOA crystal were investigated using impedance analysis. SHG efficiency of U-4MOA was spotted to be 1.71 times greater than KDP. Z-scan analysis revealed that U-4MOA has a large third order NLO susceptibility. The antimicrobial activity of the grown U-4MOA sample was performed against certain pathogens for medicament applications. In addition, the crystal packing and intermolecular interconnection were determined using Hirshfeld surface analysis.

Corona poling of PMMA based thin films doped by oxy and carboxy derivatives of [2,2]paracyclophane

Results of field corona poling experiments on thin film of polymethyl methacrylate (PMMA) polymer doped with molecules of substituted [2,2]paracyclophane are presented. Namely hydroxy/metoxy and formyl/ketone derivatives of [2,2]paracyclophane with different mutual orientation of the substituents were studied. The maximum value of second order NLO susceptibility χ(2)(−2ω;ω,ω) of 72.2 ± 7.2 p.m./V measured at 1064.2 nm fundamental wavelength was observed for phenyl substituted molecule. X-Ray structure and absorption spectroscopy data as well as quantum chemical calculations were engaged for the discussion of the values obtained.

The nonlinear optical properties and noncovalent interactions of supramolecular Donor−acceptor−donor assemblies between molecular tweezers and fullerenes

The supramolecular donor−acceptor−donor (D−A−D) system were formed between the tweezer and C60 with strong intermolecular charge transfer interactions, which enhance the two-photon absorption (TPA) cross-section. Here, we would use density functional theory method to investigate three effects of molecular structures on the intermolecular interactions and the second order NLO properties of supramolecular complexes, including: (1) the effects of N atom substitution in tweezer (2) the effects of four extra benzene rings in tweezer (3) the effect of fullerene size. It was found that the substitution of N atoms and the addition of the four extra benzene rings to tweezer weakened the intermolecule interactions between fullerene and tweezer, suggesting that they did not enhance the electron-giving capacities of tweezers. While the fullerenes of larger size can form the stronger intermolecule interaction with tweezers.

Third order NLO and second hyperpolarizability of functional porphyrin based polyimides

Porphyrin-POM hybrid materials with excellent NLO properties are supposed to be a worthy entrant for forthcoming telecommunication, optical fibers, optical data storage and optical limiting devices, but due to adverse solubility problems, they are replaced by polymeric materials. Herein, we assessed third order NLO and second hyperpolarizability of porphyrin-polyimide compounds (NH-PI and Zn-PI) synthesized from the reaction of 4,4ʹ-hexafluoroisopropylidene-diphthalic anhydride (6FDA) with C44H32N6 (NH-DATPP) and C44H30N4Zn (Zn-DATPP) porphyrins under ambient conditions. The Z-scan measurement of these compounds revealed reverse saturation absorption as well as self-defocusing performance. Zn-PI showed an enhancement in γ value (2.214 × 10−29 esu) as compared to the NH-PI (1.879 × 10−29 esu) revealing significant role of Zn ion in charge transfer process. On the other hand, Zn-DATPP exhibited χ(3) value of 7.829 × 10−11 esu which is significantly lower than the value seen for the compound NH-DATPP (15.649 × 10−11 esu) showing inverse effect due to ruffled deformation in normal coordination structure of metalloporphyrin. Furthermore, this work provides a pave to modulate the NLO response by fine structural modification in porphyrin-polyimides.

Quantum Chemical Computations of an Efficient Push-Pull NLO Chromophore 3-[4-Nitrophenyl Azo]- 9H- Carbazole-9-Ethanol

Electric-optic (EO) materials are being explored for applications ranging from fiber and satellite telecommunications, optical gyroscopes, to photonic detection of radar etc. Dipolar push-pull Organic chromophores that exhibit extended π-conjugation, in particular, show enhanced second order NLO properties. The present investigation reports the quantum chemical computations of the high efficiency push-pull NLO molecule 3-[(4-Nitrophenyl Azo)] - 9H-Carbazole-9-Ethanol (NPACE). The organic push-pull molecule is optimized in gaseous and in various solvent condition using Exchange correlation function (B3LYP/MP2). Molecular electrostatic potential, thermal properties and NBO analysis have also been performed in detail. The effective electron cloud moment in the molecule is mainly governed by the physical process termed intramolecular Charge Transfer (ICT).

Strong second order nonlinear optical properties of azulene-based porphyrin derivatives.

The high stability, feasible modification, and good π-conjugation of porphyrin derivatives render these porphyrin-based nanomaterials suitable as potential third order nonlinear optical (NLO) materials. Introducing an azulene in pristine porphyrins can significantly improve the second order NLO properties of the system, and this is studied in the present work using density functional theory based methods and the sum-over-states model. The relative orientation of azulene plays a determinant role in the enhancement of the static first hyperpolarizability (〈β0〉), e.g., the 〈β0〉 per heavy atom increases from 0.31 × 10-30 esu to 9.78 × 10-30 esu. Further addition of metals (Mg and Zn) in these azulene-fused porphyrin systems leads to an even larger 〈β0〉 per heavy atom of 41.59 × 10-30 esu, much larger than that of a recently reported porphyrin derivative (26.47 × 10-30 esu). A novel strategy to stabilize the electronic structures as well as maintain good second order NLO responses by introducing appropriate metals into the azulene-fused porphyrins is extendable to other similar systems. Strong sum frequency generation and different frequency generations of those azulene-fused porphyrins in visible and near-infrared regions may inspire experimental exploration and related applications of azulene-based porphyrins particularly in biological nonlinear optics.

Growth, structural, spectral, Hirshfeld analysis, photoluminescence, linear and third order NLO properties of a novel organic p-toluidinium succinate succinic acid single crystal

A novel organic p-toluidinium succinate succinic acid (PTSSA) single crystal with dimensions 13 × 09 × 10 mm3 was grown at ambient temperature by slow evaporation procedure. The 3D molecular structure and cell parameters of the compound were evaluated through single crystal X-ray diffraction studies. The PTSSA crystallizes in triclinic system with centrosymmetric space group P1¯. The crystal structure was stabilized by N—H…O and O—H…O bond interactions and its supramolecular aggregation have been reported. Optical band gap energy was calculated to be 4.1 eV and procures the transparency in the visible region with low UV cut-off wavelength at 279 nm. The presence of essential functional groups was identified in the grown crystal using FTIR analysis. The title crystal structure contributes the most prominent role to the H-H interactions of about 54.1%. A photoluminescence study determines the emission spectrum of the grown crystal at the red region. The open and closed aperture curve of Z-scan setup discloses the third order NLO properties of the PTSSA crystal.

Studies on the Growth, Structural, Optical, Mechanical and Nonlinear Optical Properties of Piperazinium Bis (Salicylate) Single Crystal

Organic materials have outstanding upturn striking high nonlinear optical properties. One such NLO material of good quality single crystal of protonated Piperazinium bis (Salicylate) (PSL) was synthesized by slow solvent evaporation solution growth technique. XRD studies analyzed that the PSL crystallize monoclinic system with space group P21/n. FTIR spectral analysis ascertained the frequencies of various functional groups present in PSL crystal. The optical transmittance and optical band gap were explored from the optical transmission phenomena of PSL crystal. PL studies revealed that prominent emission at 410 nm, when PSL was excited at 320 nm. The mechanically soft nature of the crystal was divulged by Vickers hardness measurement. The LDT value of PSL crystal was estimated as 2.65 GW/cm2. The third order NLO properties of PSL crystal was ascertained by Z-scan studies.

A comparative molecular structure – NLO activity study of ortho-bridged dibenzaldehydes: Synthesis, crystal structure, SHG, and DFT studies

Structural and second order nonlinear optical characteristics of four ortho-bridged dibenzaldehydes with alkyloxy- and xylenyloxy linkers are compared from the XRD, UV-Vis-NIR spectroscopic, SHG, and DFT studies. Interruption of electron polarization by π-conjugation of the linkers between the two benzaldehyde units affect their NLO properties like hyperpolarizability (β) in these acceptor–π–bridge–donor–π–bridge–acceptor (A–π–D–π–A) systems. The noncentrosymmetric 2,2′-[1,2-phenylenebis(methylenoxy)]dibenzaldehyde exhibits SHG efficiency matching with that of potassium dihydrogenphosphate (KDP) in Kurtz-Perry powder method. The acentric supramolecular architecture stabilized by H-bonding and aromatic π-π stacking interactions in the solid state with the non-linear o-xylenyloxy linker rationalizes the origin of its structure driven NLO property. Chromophore density, broad optical transparency, low cut-off wavelength of electronic absorptions, and thermal stability of 2,2′-[1,2-phenylenebis(methylenoxy)]dibenzaldehyde make it a promising candidate for second order NLO applications.

Synthesis, antimicrobial activity and DFT studies of 4,5-dihydro-9-methoxy-4-(5-methylisoxazol-3-yl)benzo[f][1,4]oxazepin-3(2H)-one

A new 4,5-dihydro-9-Methoxy-4-(5-Methylisoxazol-3-yl)Benzo[f][1,4]Oxazepin-3(2H)-One (5) was prepared by taking a facile and simple methodology. The reaction of 3-amino-5-methylisoxazole (1) with 3-methoxy salicylaldehyde (2), pursued by reduction with NaBH4, and insitu chloroacetylation and cyclization with chloroacetyl chloride and triethyl amine affords isoxazolyl benzo[f][1,4]oxazepin-3-(2H)-one (5). The structures of the synthesized molecules (3–5) were established with the help of 1H NMR and 13C NMR data. Title compound 5 has been evaluated for their invitro antibacterial and antifungal activity against different bacterial and fungal strains, results revealed tested compound show good antimicrobial activity, when compared to the respective standard drugs. The theoretical studies such as optimized structural parameters, Frontier molecular orbitals (FMO’s), polarizability (α), first order hyperpolarizability (β), dipole moment, NLO properties, thermodynamic parameters and Molecular electrostatic potential (MEP) were calculated by using DFT/B3LYP/6–311++G(d,p) method for compound 5. Theoretical NMR chemical shifts of the molecule were computed using GIAO method.

Promising computational, structural, vibrational and optical properties of piperazinium bis(2-carboxypyridine)monohydrate (PBCPM) crystal for NLO device applications

The Slow Evaporation Solution Technique (SEST) was used to produce a single crystal of piperazinium bis(2-carboxypyridine)monohydrate (PBCPM). The lattice parameters and molecular structure of the grown crystal were determined using Single Crystal X-Ray Diffraction. The intramolecular and intermolecular interactions were visualised using Hirshfeld surface analysis. The B3LYP level of theory with a 6–31++G (d,p) basis set was used to compute the Molecular optimised geometry. The FT-IR and FT-R spectral studies that have been reported look at the modes of vibration of various functional groups in the PBCPM crystal. The grown crystal has a high transmittance in the entire visible field, according to UV–vis transmittance reports. Based on the finite-field approach, the polarizability and hyperpolarizability of PBCPM is determined using the DFT-B3LYP method and the 6–311G(d,p) basis set. The Z-scan technique is used to perform third order NLO studies on the PBCPM crystal. The result discussed confirms that PBCPM crystal is a potential candidate for future NLO device applications.

Linear and nonlinear optical properties of 2-Aminopyridinium fumarate fumaric acid single crystal for optoelectronic device applications

A good organic nonlinear optical single crystal of 2-Aminopyridine fumarate fumaric acid has been grown by slow evaporation technique. The analysis of single-crystal XRD demonstrates the centrosymmetric character of the grown crystal. The different functional groups and chemical composition are of 2APFF compounds were identified by using Fourier transform infrared spectral study. Spectral range of UV–vis-NIR studies shown that the transparency and band gap energy Eg = 6 eV of the grown crystal. Thermal property of 2APFF was analysed by differential scanning calorimetric technique. The mechanical properties 2APFF crystal was calculated for various load using the Vickers micro hardness tester. The dielectric behaviour of the grown crystal was studied for different temperatures at different frequencies. The third order NLO response in 2APFF was investigated using a Z-scan apparatus.

Vibrational spectroscopy, quantum computational and molecular docking studies on 2-chloroquinoline-3-carboxaldehyde

The quantum mechanical density functional theory (DFT) approach was used to analyze vibrational spectroscopy for the title compound 2-chloroquinoline-3-carboxaldehyde, and the observations were compared to experimental results. B3LYP with the 6–311++ G (d, p) basis set produces the optimized molecular structure and vibrational assignments. The charge delocalization and hyper conjugative interactions were studied using NBO analysis. Fukui functions were used to determine the chemical reactivity of the examined molecule. The linear polarizability, first order polarizability, NLO and Thermodynamic properties are calculated. Additionally, Molecular electrostatic potential (MEP) and HOMO-LUMO are reported. Multi wavefunction analysis like ELF (Electron Localization Function) and LOL (Localized Orbital Locator) are analyzed. For the headline compound, drug-likeness properties were examined. Molecular docking analysis on the examined molecule are done to understand the biological functions of the headline molecule and the minimum binding energy, hydrogen bond interactions, are analyzed.

Inorganic electrides of alkali metal doped Zn12O12 nanocage with excellent nonlinear optical response

Finding new materials with exceptionally large nonlinear optical response is an interesting and challenging avenue for scientific research. Here, we report the alkali metal doped Zn12O12 nanocages as inorganic electrides with excellent nonlinear optical response. Density functional theory calculations have been performed for geometric, electronic and nonlinear optical response of exo- and endohedrally alkali metal doped Zn12O12 nanoclusters. For exohedral doping, all different possible doping sites are considered for decoration of alkali metal on the nanocage. The electride nature of the complexes is highly dependent on the position of alkali metal doping. All exohedral complexes except for alkali metal doping on six membered ring (r6) are electride in nature, as revealed from frontier molecular orbital analysis. Interaction energies reveal that all doped nanoclusters except endo-K@Zn12O12 are thermodynamically stable. The exothermic encapsulation of alkali metals in Zn12O12 nanocages is in marked contradiction with other inorganic fullerenes where encapsulation is an endothermic process. The barriers for boundary crossing are also evaluated in order study the interconversion of exo- and endohedral complexes. Doping of alkali metal significantly influences the properties of nanocages. HOMO-LUMO (H-L) gap is reduced significantly whereas hyperpolarizability is increased several orders of magnitude. The NLO response of exohedrally doped complexes is higher than the corresponding endohedral complexes, which is in mark contradiction with the behavior of phosphide or nitride nanocages. The highest first hyperpolarizability of 1.0 × 105 au is calculated for K@r6-Zn12O12 complex. Third order NLO response of these complexes is calculated and compared with the best systems reported in the literature at the same level of theory.

Experimental and Theoretical Investigations on a Hydrous Organic salt of 2,4,6-triaminopyrimidine-1,3-diium L-tartrate monohydrate (TTM)

A hydrous organic salt of 2,4,6-triaminopyrimidine-1,3-diium L-tartrate monohydrate (TTM) has been synthesized. The structural investigations revealed the acentric crystalline packing (monoclinic system with P21 space group) of TTM crystal. The carboxylate (O5__C8__O6) group of L-tartrate anion linked to the nitrogen atoms (N3 and N4) of cation via a pair of N__H…O hydrogen bonds (N(3)__H(4)…O(6) (-x,+y-1/2,-z+1) and N(4)__H(5)…O(5) (-x,+y-1/2,-z+1)) and formed a R22(8)ring motif. Hirshfeld surface and finger print analysis were carried out to investigate the contribution of N__H…O and O__H…O and C__H…O intermolecular interactions to the structural stabilization of TTM crystal. FTIR and FT-Raman vibrational studies were effectively performed to investigate the vibrational modes of various functional groups in TTM crystal. Second order NLO property of title crystal was confirmed by modified Kurtz-Perry second harmonic generation technique. The relationship between the molecular structure and properties were investigated for TTM molecule by systematic quantum chemical calculations using density functional theory (DFT).

Transition metals induce control of enhanced NLO properties of functionalized organometallic complexes under laser modulations

The molecular engineering of organometallic complexes has recently attracted renewed interest on account of their potential technological applications for optoelectronics in general and optical data storage. The transition metal which induces control of enhanced nonlinear optical properties of functionalized organometallic complexes versus not only the intensity but also the polarization of the incident laser beam is original and important for all optical switching. This makes organometallic complexes valuable and suitable candidates for nonlinear optical applications. In the present work, we report the synthesis and full characterization of four organometallic complexes consisting of N, N-dibutylamine and azobenzene fragments but differ by auxiliary alkynyl ligands or metal cations. Thus, a ferrocenyl derivative 1 and three ruthenium complexes 2–4 have been prepared. The nonlinear optical properties of the four new azo-based ruthenium and iron organometallic complexes in the solid state, using polymethylmethacrylate as matrix, have been thoroughly studied. This concept is extended to computing the HOMO and LUMO energy levels of the considered complexes, dipole moment, first and second order hyperpolarizabilities using the 6–31 + G(d,p) + LANL2DZ mixed basis set. The second and third nonlinear optical properties of the resulting polymer composites were obtained by measuring SHG and THG response by means of the Maker fringe technique using a laser generating at 1,064 nm with a 30 ps pulse duration. The values of the second and third order NLO susceptibilities of the four organometallic complexes were found to be higher than the common references used. Theoretical calculation shows that the large first and second order hyperpolarizablities are caused by strong intramolecular charge transfer between the transition metal parts and the ligands though a conjugated transmitter. These results indicate that the present organometallic complexes are valuable candidates for optoelectronic and photonic applications.

Optical, spectral and NLO properties of L-Leucine potassium chloride crystals

L-Leucine potassium chloride (LLPC) crystals have been synthesized and grown by cost effective slow evaporation technique in water as a solvent. The single crystal XRD analysis shows that the grown crystal has monoclinic structure and X-ray powder diffraction study indicates the crystalline nature of the compound. The FT-IR spectroscopic studies reveal the various functional groups of the sample. The linear optical properties of the grown LLPC crystals were studied by recording the UV–Vis-NIR spectrum in the range 200–1100 nm. The Second harmonic generation efficiency of the title material was tested using Kurtz and Perry experimental technique which reveals that L-Leucine potassium chloride crystal is the potential candidate for nonlinear optical applications. Third order NLO parameters like nonlinear absorption coefficient, refractive index nonlinear and nonlinear susceptibility of LLPC crystals were analysed by Z-scan method.

From Halo Effective Field Theory to the study of breakup and transfer reactions: reliably probing the halo structure of 11Be and 15C

In this work we study one-neutron halo nuclei, and in particular 11Be and 15C, which can be seen as an inert core of 10Be or 14C plus a loosely bound neutron. During the last decades several transfer and breakup reactions involving these systems have been measured on different targets and energies. We study these processes using one single structure model for each nucleus applying the halo effective field theory (Halo EFT) at next-to-leading order NLO. The main parameters of this EFT are adjusted on nuclear-structure data and/or ab initio predictions. We model the transfer reaction within the Adiabatic Distorted Wave Approximation (ADWA) and the breakup process applying an eikonal model with a consistent treatment of nuclear and Coulomb interactions at all orders. At high energy, our model includes a proper treatment of special relativity Our theoretical calculations are in good agreement with experiment for a variety of reaction observables, thus assessing the robustness of the structure model provided for these nuclei. This new idea enables us also to reliably estimate the nuclear-structure observables that actually affect the reaction process, and hence that can be inferred from such measurements.

Investigation on the growth, optical, electrical, thermal and third order NLO properties of 2-(4-methlybenzylidene) malononitrile (MBM) single crystal

More effective organic charge transfer nonlinear optical material of 2-(4-methlybenzylidene) malononitrile (MBM) has been synthesized via knoevenagel condensation reaction method and single crystals of unprecedented MBM were successfully cultivated in the presence of ethanol solution by the adaption of slow evaporation solution growth method. Cell parameters and phase purity of the obtained MBM crystals were investigated with the help of Single crystal and powder X-ray diffraction analysis. The morphology of the grown crystal was generated using WinXMorph software. Linear optical characterization was carried out in order to figure out its transmittance efficiency (82%), cut-off wavelength (λ = 458 nm) and energy band gap (Eg = 3.05eV) of the title material. Electrical behavior of the MBM crystal was examined on the basis of dielectric properties. Title crystals thermal tolerance and melting point was examined through TG-DSC analysis. The grown MBM crystal was subjected to Single beam Z-scan technique in order to figure out its third order nonlinear optical nature and its susceptibility is compared with other reported centrosymmetric crystals. Considering its large transmittance range, thermal stability and effective NLO performance, MBM is a potential candidate for NLO applications.

Growth and Z-scan analysis of semi-organic Bis(picolinic acetate) Zinc(II) single crystal for third order NLO applications

Here, we report a new semi-organic single crystal namely Bis(picolinic acetate) Zinc(II) (BPZ) which was grown by a conventional slow evaporation method at room temperature. Structural studies were carried out by single crystal XRD and the results show that Bis(picolinic acetate) Zinc(II) belongs to monoclinic crystal system with space group P21/n. The presence of functional groups in the grown crystal was identified by FTIR spectral analysis. UV-Vis spectral studies reveal that the grown crystals are transparent in the wavelength region of 200-1200 nm. In order to analyze the mechanical strength of the grown crystal, Vickers micro hardness tester was employed. The dielectric properties with respect to different frequency at room temperature were also studied to analyze the dielectric response. The third order nonlinear optical properties were determined by Z-scan studies which shows significant higher values of nonlinear absorption coefficient (β) and third order nonlinear susceptibility (χ3). The enhanced third order nonlinear behavior suggests that the title compound is suitable for nonlinear optical applications.