Showing papers on "Hyperpolarizability published in 2016"
TL;DR: In this article, the properties of conjugated azo-based iminopyridine complexes with zinc and silver metal cations were studied and the processes of second and third harmonic generations in guest-host polymeric films were investigated and NLO parameters were extracted.
99 citations
TL;DR: In this paper, the properties of doped boron nitride nanocages (MB 12 N 11 and MB 11 N 12 ) have been investigated theoretically, and it is revealed that first hyperpolarizability (β 0 ) is increased to a larger extent (1.3 ǫ× 10 4 au ) for KB 12 n 11 as compared to pure B 12 N 12 (0 au).
94 citations
TL;DR: The present work realizes the potential of designed derivatives as efficient NLO-phores for modern NLO applications by effectively tuning the second-order nonlinear optical (NLO) properties in some chalcone derivatives.
Abstract: Using the density functional theory methods, we effectively tune the second-order nonlinear optical (NLO) properties in some chalcone derivatives. Various unique push-pull configurations are used to efficiently enhance the intramolecular charge transfer process over the designed derivatives, which result in significantly larger amplitudes of the first hyperpolarizability as compared to their parent molecule. The ground state molecular geometries have been optimized using B3LYP/6-311G** level of theory. A variety of methods including B3LYP, CAM-B3LYP, PBE0, M06, BHandHLYP and MP2 are tested with 6-311G** basis set to calculate the first hyperpolarizability of parent system 1. The results of M06 are found closer to highly correlated MP2 method, which has been selected to calculate static and frequency dependent first hyperpolarizability amplitudes of all selected systems. At M06/6-311G** level of theory, the permanent electronic dipole moment (μtot), polarizability (α0) and static first hyperpolarizability (βtot) amplitudes for parent system 1 are found to be 5.139 Debye, 274a. u. and 24.22×10(-30)esu, respectively. These amplitudes have been significantly enhanced in designed derivatives 2 and 3. More importantly, the (βtot) amplitudes of systems 2 and 3 mount to 75.78×10(-30) and 128.51×10(-30)esu, respectively, which are about 3 times and 5 times larger than that of their parent system 1. Additionally, we have extended the structure-NLO property relationship to several newly synthesized chalcone derivatives. Interestingly, the amplitudes of dynamic frequency dependent hyperpolarizability μβω (SHG) are also significantly larger having values of 366.72×10(-48), 856.32×10(-48) and 1913.46×10(-48)esu for systems 1-3, respectively, at 1400nm of incident laser wavelength. The dispersion behavior over a wide range of change in wavelength has also been studied adopting a range of wavelength from 1907 to 544nm. Thus, the present work realizes the potential of designed derivatives as efficient NLO-phores for modern NLO applications.
74 citations
TL;DR: It is demonstrated that the tuning of the light emission from red to blue in dihydrolipoic acid (DHLA) capped Ag29 nanoclusters can be trigged with one and two photon excitations, and the density functional theory (DFT) provides insight into the structural and electronic properties of Ag29(D HLA)12.
Abstract: We demonstrate that the tuning of the light emission from red to blue in dihydrolipoic acid (DHLA) capped Ag29 nanoclusters can be trigged with one and two photon excitations. The cluster stoichiometry was determined with mass spectrometry and found to be Ag29(DHLA)12. In a detailed optical investigation, we show that these silver nanoclusters exhibit a strong red photoluminescence visible to the naked eye and characterized by a quantum yield of nearly ∼2% upon one-photon excitation. In the nonlinear optical (NLO) study of the properties of the clusters, the two-photon excited fluorescence spectra were recorded and their first hyperpolarizability obtained. The two-photon absorption cross-section at ∼800 nm for Ag29(DHLA)12 is higher than 10(4) GM and the hyperpolarizability is 106 × 10(-30) esu at the same excitation wavelength. The two-photon excited fluorescence spectrum appears strongly blue-shifted as compared to the one-photon excited spectrum, displaying a broad band between 400 and 700 nm. The density functional theory (DFT) provides insight into the structural and electronic properties of Ag29(DHLA)12 as well as into interplay between metallic subunit or core and ligands which is responsible for unique optical properties.
71 citations
TL;DR: In this paper, the 3, 4, 4-Dimethoxy -4′-methoxychalcone (DMMC) was grown by slow evaporation solution growth technique in acetone at ambient temperature and the lattice parameters were estimated from powder X-ray diffraction.
Abstract: Transparent good quality single crystals of organic nonlinear optical material, 3, 4-Dimethoxy -4′-methoxychalcone (DMMC) were grown by slow evaporation solution growth technique in acetone at ambient temperature. The lattice parameters were estimated from powder X-ray diffraction. The crystalline perfection has been evaluated by high resolution X–ray diffractometry (HRXRD). The UV–vis-NIR absorption spectrum reveals that the crystal is transparent between 440 nm and 900 nm for optical applications. The fluorescence spectrum shows a peak at about 482 nm and indicates that the crystal has a blue fluorescence emission. The third order nonlinear optical properties of solution of DMMC in N, N-Dimethylformamide (DMF) solvent has been investigated using Z-scan technique with femtosecond (fs) Ti:sapphire laser pulses at 800 nm wavelength. The calculated values of nonlinear refractive index, nonlinear absorption coefficient, and the magnitude of third-order susceptibility are of the order of − 7.7×10-14cm2/W, 1.7×10−9 cm/W and 6.7×10−12 e.s.u. respectively. The two photon absorption (2PA) cross section and molecular second-order hyperpolarizability values obtained is of the order of 10−49 cm4 s/photon/molecule and 2.8×10−31 e.s.u. respectively. The crystal shows optical-limiting (OL) effects for femtosecond laser pulses at 800 nm. The results suggest that the nonlinear properties investigated for DMMC are comparable with some of the reported chalcone derivatives and can be desirable for nonlinear optical applications.
70 citations
TL;DR: In this article, the fundamental vibrational frequencies and intensity of vibrational bands were evaluated using density functional theory (DFT), and the vibrational analysis of stable isomer of O-methoxy benzaldehyde (OMB) has been carried out by FT-IR and FT-Raman in combination with theoretical method simultaneously.
66 citations
TL;DR: In this paper, density functional theory calculations have been carried out to investigate the nonlinear optical response of the B 40 fullerene by interaction with the alkali metals (Li, Na, K).
65 citations
TL;DR: The effect of alkali metal doping in aluminum nitride (Al12N12) nanocages through density functional theory (DFT) methods is studied in this article, where the stability of the doped nano-cages is evaluated through binding energy calculations.
Abstract: The effect of alkali metal (Li, Na, and K) doping in aluminum nitride (Al12N12) nanocages is studied through density functional theory (DFT) methods. Six new stable compounds of M@Al12N11 and M@Al11N12 are designed theoretically where alkali metal replaces an atom (Al/N) of a nanocage. The stability of the doped nano-cages is evaluated through binding energy calculations. Doping alkali atom M (M = Li, Na, K) into a nanocage significantly reduces the band gap (HOMO–LUMO gap). Polarizability and first hyperpolarizability are calculated using long range separated methods to evaluate the non-linear optical (NLO) properties of these doped systems. The hyperpolarizability of MAl12N11 nanocages is much higher than that of M@Al11N12 nanocages. The higher hyperpolarizability of M@Al12N11 nanocages is believed to arise from participation of excess diffuse electrons, revealed from PDOS.
59 citations
TL;DR: The fundamental mechanism of the y–γ correlation has been explained by using a simple two‐site model and the valence configuration interaction method, and several molecular design guidelines for controlling γ have been proposed, which open a new path toward understanding the structure—NLO property relationships and toward realizing a new class of highly efficient NLO materials.
Abstract: For more than 30 years, nonlinear optical (NLO) properties of molecular systems have been actively studied both theoretically and experimentally due to their potential applications in photonics and optoelectronics. Most of the NLO molecular systems are closed-shell species, while recently open-shell molecular species have been theoretically proposed as a new class of NLO systems, which exhibit larger NLO properties than the traditional closed-shell NLO systems. In particular, the third-order NLO property, the second hyperpolarizability γ, was found to be strongly correlated to the diradical character y, which is a quantum-chemically defined index of effective bond weakness or of electron correlation: the γ values are enhanced in the intermediate y region as compared to the closed-shell (y = 0) and pure open-shell (y = 1) domains. This principle has been exemplified by accurate quantum-chemical calculations for polycyclic hydrocarbons including graphene nanoflakes, multinuclear transition-metal complexes, main group compounds, and so on. Subsequently, some of these predictions have been substantiated by experiments, including two-photon absorption. The fundamental mechanism of the y–γ correlation has been explained by using a simple two-site model and the valence configuration interaction method. On the basis of this y–γ principle, several molecular design guidelines for controlling γ have been proposed. They consist in tuning the diradical characters through chemical modifications of realistic open-shell singlet molecules. These results open a new path toward understanding the structure—NLO property relationships and toward realizing a new class of highly efficient NLO materials. WIREs Comput Mol Sci 2016, 6:198–210. doi: 10.1002/wcms.1242
58 citations
TL;DR: This work studies the longitudinal static second hyperpolarizability of all-trans polyenes C2nH2n+2 in the cc-pVDZ basis set and implements internally contracted complete active space second order perturbation theory with the density matrix renormalization group (DMRG) as active space solver.
Abstract: We have implemented internally contracted complete active space second order perturbation theory (CASPT2) with the density matrix renormalization group (DMRG) as active space solver [Y. Kurashige and T. Yanai, J. Chem. Phys. 135, 094104 (2011)]. Internally contracted CASPT2 requires to contract the generalized Fock matrix with the 4-particle reduced density matrix (4-RDM) of the reference wavefunction. The required 4-RDM elements can be obtained from 3-particle reduced density matrices (3-RDM) of different wavefunctions, formed by symmetry-conserving single-particle excitations op top of the reference wavefunction. In our spin-adapted DMRG code chemps2 https://github.com/sebwouters/chemps2, we decompose these excited wavefunctions as spin-adapted matrix product states and calculate their 3-RDM in order to obtain the required contraction of the generalized Fock matrix with the 4-RDM of the reference wavefunction. In this work, we study the longitudinal static second hyperpolarizability of all-trans polyenes C2nH2n+2 [n = 4-12] in the cc-pVDZ basis set. DMRG-SCF and DMRG-CASPT2 yield substantially lower values and scaling with system size compared to RHF and MP2, respectively.
57 citations
TL;DR: In this article, three quadrupolar D−π−A−π-D compounds, bearing alkoxy phenyls as mild electron donors and a benzothiadiazole (A), two benzothiamadiazoles (B), or a benzithiadizole linked to two thiophenes (C) as the acceptor units, are collectively the object of this study.
Abstract: Three quadrupolar D−π–A−π–D compounds, bearing alkoxy phenyls as mild electron donors and a benzothiadiazole (A), two benzothiadiazoles (B), or a benzothiadiazole linked to two thiophenes (C) as the acceptor units, are collectively the object of this study. They proved to be efficient yellow/orange/red fluorophores, respectively, with fluorescence being their preferred deactivation pathway. These systems exhibited positive fluorosolvatochromism and a noticeable decrease of the fluorescence quantum yield in the most polar solvent (with the quenching following the trend B > A > C). These findings point to an intramolecular charge transfer (ICT) nature of the emitting state, whose photoinduced dynamics was investigated by femtosecond-resolved transient absorption and fluorescence upconversion. Remarkable values of hyperpolarizability were estimated by the solvatochromic method. The significant two-photon absorption cross sections measured for A–C (whose trend nicely parallels that of ICT efficiency), coupled...
TL;DR: It is demonstrated that the coherence of a single mobile atomic qubit can be well preserved during a transfer process among different optical dipole traps (ODTs) and hyperpolarizability is measured for the first time.
Abstract: We demonstrate that the coherence of a single mobile atomic qubit can be well preserved during a transfer process among different optical dipole traps (ODTs). This is a prerequisite step in realizing a large-scale neutral atom quantum information processing platform. A qubit encoded in the hyperfine manifold of an ^{87}Rb atom is dynamically extracted from the static quantum register by an auxiliary moving ODT and reinserted into the static ODT. Previous experiments were limited by decoherences induced by the differential light shifts of qubit states. Here, we apply a magic-intensity trapping technique which mitigates the detrimental effects of light shifts and substantially enhances the coherence time to 225±21 ms. The experimentally demonstrated magic trapping technique relies on the previously neglected hyperpolarizability contribution to the light shifts, which makes the light shift dependence on the trapping laser intensity parabolic. Because of the parabolic dependence, at a certain "magic" intensity, the first order sensitivity to trapping light-intensity variations over ODT volume is eliminated. We experimentally demonstrate the utility of this approach and measure hyperpolarizability for the first time. Our results pave the way for constructing scalable quantum-computing architectures with single atoms trapped in an array of magic ODTs.
TL;DR: In this paper, the energy dependence of π mesons off the background Abelian magnetic field on the base of quenched SU(3) lattice gauge theory was explored and the magnetic dipole polarizability of charged and neutral pions for various lattice volumes and lattice spacings was calculated.
TL;DR: In this article, a comprehensive structural and vibrational study of 2-(4-oxo-3-phenethyl-3,4-dihydroquinazolin-2-ylthio)-N-(3, 4,5-trimethoxyphenyl) acetamide is reported.
TL;DR: In this article, the second and third orders of nonlinear optics properties of unsubstituted chalcone (C15H12O) and mono-sub-substitution (C16H14O2) in solution, using hyper-Rayleigh scattering and Z-Scan techniques, were described.
TL;DR: In this paper, a single crystal of 2-amino 5-chloropyridinium 4-carboxybutanoate (2A5C4C) with sizes of 7 × 4 × 2 mm3 was grown by a slow evaporation solution growth technique at room temperature using methanol solvent.
Abstract: Optically transparent organic single crystals of 2-amino 5-chloropyridinium 4-carboxybutanoate (2A5C4C) with sizes of 7 × 4 × 2 mm3 were grown by a slow evaporation solution growth technique at room temperature using methanol solvent. The lattice parameter values of the crystals were evaluated by single crystal XRD; the results confirmed that 2A5C4C crystal belongs to the orthorhombic system with cell parameters of a = 5.1858 A, b = 14.501 A and c = 15.963 A. The crystalline phases and quality of the grown crystals were ascertained by powder XRD and high resolution XRD (HRXRD) studies, respectively. The crystal structure and various functional groups present in 2A5C4C were confirmed by 1H, 13C NMR and FTIR analysis. The optical absorption, transmittance and lower cutoff wavelength were identified by UV-Vis-NIR studies. The optical band gap was estimated from the Tauc plot and was found to be about 3.68 eV. The charge transport mechanism and photoconducting nature of 2A5C4C were analyzed using dielectric and photoconductivity studies, and the obtained results were compared with previously reported values. In order to analyze the thermal and mechanical stability properties of the 2A5C4C crystal, TG/DTA and Vickers microhardness studies were performed. The laser-induced surface damage threshold values for the grown crystal were measured using a Nd:YAG laser. Powder SHG analysis was also carried out for powder samples using the Kurtz and Perry powder second harmonic generation (SHG) technique; the results were compared with KDP as a reference. The theoretical molecular electrostatic potential, HOMO–LUMO, natural bonding orbital analysis (NBO) and first hyperpolarizability values of the 2A5C4C molecule were calculated and discussed in detail. Moreover, the hydrogen bonded charge transfer crystal was screened for its pharmacological antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide (H2O2) radicals.
TL;DR: In this article, the nonlinear optical response of CH3NH3PbBr3 perovskites was investigated using Z-scan technique, employing 10ns laser pulses, at 532nm.
TL;DR: In this paper, the structure of C11H7BrO3 has been determined using 3330 measured reflections with 1666 unique [Rint = 0.0088] with final indices R1= 0.0128 [I>2σ(I)] and wR2 = 0.0347 (all data).
TL;DR: In this paper, the authors used density functional theory and time-dependent density functional theories to determine how the size of π-conjugated system influences the absorption spectra and non-linear optical properties of dyes.
Abstract: In this study, density functional theory and time-dependent density functional theory are used to determine how the size of π-conjugated system influences the absorption spectra and non-linear optical (NLO) properties of dyes. Double and triple bonds, as well the benzene rings, are used in conjugated systems. The results of the theoretical computation show that the absorption spectra are gradually broadened and red-shifted with increases in the conjugation length. Theoretical examination of the NLO properties was performed on the key parameters of polarizability and hyperpolarizability. A notable increase in the non-linear optical response was observed with an increase in the conjugation length of the π-spacer.
TL;DR: In this paper, a cobalt-II complex of 6-methylpicolinic acid, Co(6-Mepic)2(H2O)2]·2H 2O, was prepared and fully determined by single crystal X-ray crystal structure analysis as well as FT-IR, FT-Raman.
TL;DR: In this article, a push pull chromophore was synthesized by a multi-step reaction starting from 9 H -carbazole-2-ol and showed high fluorescent intensity in aggregate forms and in solid state.
TL;DR: In this article, an electride molecule with two easily driven excess electrons at two opposite ends of the molecule was designed theoretically for the first time, and a novel switching mechanism of electronic structure isomerization emerged as a distinctive nonbonding evolution in the electride molecules.
Abstract: An electride molecule e–···K(1)+···calix[4]pyrrole···K(2)+···e– as an external electric field (F) manipulated nonlinear optical (NLO) switch is designed theoretically for the first time. As this molecule is an unusual singlet diradical electride molecule with two easily driven excess electrons (by electric field) at two opposite ends of the molecule, a novel switching mechanism of electronic structure isomerization emerges as a distinctive nonbonding evolution in the electride molecule. A small electric field driving leads to a long-range excess electron transfer from one side K(1) through the middle calix[4]pyrrole to the other side K(2), forms a lone excess electron pair of s-type rather than a single bond, and quenches the singlet diradical. Meanwhile, the molecular electronic structure becomes K(1)+···calix[4]pyrrole···K(2)+···2e–. Therefore, the small electric field driving brings a very high static first hyperpolarizability (β0) contrast from 0 (F = 0, Off form) to 4.060 × 105 au (F = a small nonzer...
TL;DR: The TKS analysis suggests that relative to analogous dipolar chromophores, octopolar supermolecules will be likely characterized by more intricate dependences of the measured hyperpolarizability upon irradiation wavelength due to the interactions among multiple different β tensor components.
Abstract: Octopolar D2-symmetric chromophores, based on the MPZnM supermolecular motif in which (porphinato)zinc(II) (PZn) and ruthenium(II) polypyridyl (M) structural units are connected via ethyne linkages, were synthesized. These structures take advantage of electron-rich meso-arylporphyrin or electron-poor meso-(perfluoroalkyl)porphyrin macrocycles, unsubstituted terpyridyl and 4′-pyrrolidinyl-2,2′;6′,2″-terpyridyl ligands, and modulation of metal(II) polypyridyl-to-(porphinato)zinc connectivity, to probe how electronic and geometric factors impact the measured hyperpolarizability. Transient absorption spectra obtained at early time delays (tdelay < 400 fs) demonstrate fast excited-state relaxation, and formation of a highly polarized T1 excited state; the T1 states of these chromophores display expansive, intense T1 → Tn absorption manifolds that dominate the 800–1200 nm region of the NIR, long (μs) triplet-state lifetimes, and unusually large NIR excited absorptive extinction coefficients [e(T1 → Tn) ∼ 105 M–...
TL;DR: In this paper, a combined experimental and theoretical study on molecular structure and vibrational spectra of 3,5 di tert butyl 4 hydroxy benzoic acid is presented.
TL;DR: In this article, the vibrational frequencies of 5-chloro-N -(3-nitrophenyl)pyrazine-2-carboxamide have been obtained using density functional theory technique in the B3LYP approximation and CC-pVDZ (5D, 7F) basis set.
TL;DR: Kurashige et al. as discussed by the authors have implemented internally contracted complete active space second order perturbation theory (CASPT2) with the density matrix renormalization group (DMRG) as active space solver.
Abstract: We have implemented internally contracted complete active space second order perturbation theory (CASPT2) with the density matrix renormalization group (DMRG) as active space solver [Y. Kurashige and T. Yanai, J. Chem. Phys. 135, 094104 (2011)]. Internally contracted CASPT2 requires to contract the generalized Fock matrix with the 4-particle reduced density matrix (4-RDM) of the reference wavefunction. The required 4-RDM elements can be obtained from 3-particle reduced density matrices (3-RDM) of different wavefunctions, formed by symmetry-conserving single-particle excitations op top of the reference wavefunction. In our spin-adapted DMRG code chemps2 [this https URL], we decompose these excited wavefunctions as spin-adapted matrix product states, and calculate their 3-RDM in order to obtain the required contraction of the generalized Fock matrix with the 4-RDM of the reference wavefunction. In this work, we study the longitudinal static second hyperpolarizability of all-trans polyenes C$_{2n}$H$_{2n+2}$ [n = 4 - 12] in the cc-pVDZ basis set. DMRG-SCF and DMRG-CASPT2 yield substantially lower values and scaling with system size compared to RHF and MP2, respectively.
TL;DR: The title compound 1-(3-chloro-4-fluorophenyl)-3-[3-(trifluoromethyl) phenyl]thiourea (ANF-2) was synthesized and structurally characterized by single crystal XRD as discussed by the authors.
Abstract: The title compound 1-(3-chloro-4-fluorophenyl)-3-[3-(trifluoromethyl) phenyl]thiourea (ANF-2) was synthesized and structurally characterized by single crystal XRD. The optimized molecular structure, vibrational frequencies, and corresponding vibrational assignments of ANF-2 have been investigated experimentally and theoretically using Gaussian 09 and Schrodinger Materials Science Suite software packages. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. Gauge-including atomic orbital NMR chemical shifts calculations were carried out and compared with experimental data, while the first hyperpolarizability is 48 times that of the standard NLO material. The maximum negative region is localized over the CS group and 1,3-disubstituted phenyl ring, while the maximum positive region is localized on NH groups indicating a possible site for nucleophilic attack. Average local ionization energies have been mapped to the electron density surface in order to detect molecule sites where electrons are least tightly bound. Other possible reactive centers of the title molecule have been detected by calculation of Fukui functions. In order to investigate the possibility for autoxidation and hydrolysis of the investigated molecule, we have calculated bond dissociation energies and radial distribution functions. Charge hopping properties have been assessed using the Marcus semi-empiric approach and the results were compared with urea and thiourea molecules. The docked ligand forms a stable complex with prostaglandin E synthase and has a binding affinity value of −6.5 kcal mol−1 and the title compound can be a lead compound for developing new analgesic drugs.
TL;DR: The results show that both solvent polarity and relative strength of the donor groups have significant impact on the electric properties, but more strikingly on the first hyperpolarizability β.
Abstract: We calculated the nonlinear optical properties of 24 azo-enaminone derivatives, incorporating solvent effects on their geometric and electronic structure, to assess the impact of the environment on these properties. Namely, we incorporated chloroform, tetrahydrofuran, acetone, ethanol, methanol, and dimethyl sulfoxide in our calculations and compared our results incorporating solvent effects with our gas-phase calculations. To account for the electron correlation effects on NLO properties, we performed the calculations at MP2/6-31G(p)//MP2/6-31G(d) level set. The polarizable continuum model was used to simulate the presence of the solvent. The exponents of p extra functions added to heavy atoms were obtained, imposing the maximization of the first hyperpolarizability. Two structural configurations (Z and E) of azo-enaminones were investigated to assess the isomeric effects of the electric properties. Our results show that both solvent polarity and relative strength of the donor groups have a significant i...
TL;DR: A series of pyrazole based derivatives with large stokes shift have been synthesized from 1,3-dipheny-1H-pyrazole-3-carbaldehyde by reacting with a series of active methylenes and characterized by spectroscopic analysis as discussed by the authors.