Nonlinear Optical Properties Properties Research Articles

Low‐Temperature Flexibility of Chiral Organic Crystals with Highly Efficient Second‐Harmonic Generation

AbstractFlexible crystals with unique mechanical properties have presented potential for applications in optoelectronics, soft robotics and sensors. However, there have been no reports of low‐temperature‐resistant flexible crystals with second‐order nonlinear optical properties (NLO). Here, we report flexible chiral Schiff‐base crystals capable of efficient second harmonic generation (SHG). Both enantiomers and the racemic form of these crystals are mechanically flexible in two directions at both room temperature and at 77 K, although their mechanical responses differ. The enantiomers display SHG with an intensity of up to 12 times that of potassium dihydrogenphosphate (KDP) when pumped at 980 nm, and they also have high laser‐induced damage thresholds (LDT). Even when bent, the crystals retain strong second harmonic generation, although with a different intensity distribution depending on the polarization, compared to when they are straight. This work describes the first instance of flexible organic single‐crystalline material with NLO properties and lays the foundation for the development of mechanically flexible organic NLO materials.

Comparing the linear and non-linear optical properties of keto-enol forms of N-alkyl, N-aryl, and O-alkyl substituted 2-Hydroxybenzophenone

The Geometrical, electronical, spectral, linear, and non-linear optical properties (NLO) of keto-enol forms of 2-hydroxybenzophenone (2-HBp) derivatives were examined. Ten pairs of 2-HBp derivatives having D-π-A framework with N-alkyl (ethyl, julolidine), N-aryl (phenyl), O-methyl, groups as donor, phenyl ring as aspacer, and carbonyl group linked to phenyl ring consisting of either mono or dicarboxylic acid group as acceptor, were selected. DFT results suggest thatthe keto form is stablein the S0 and S1 states. Further, IR spectra, CV analysis, experimental absorption maxima, and TD-DFT results support the existence of 2-HBp derivatives in keto form. Thermogravimetric analysis shows that 2-HBp derivatives have remarkable thermal stability (∼200 °C), enabling their practical application in NLO. Further, DFT and TD-DFT results show that theketo form of 2-HBp derivatives with lower BLA, higher μ, ω, η, Γ, and hyperpolarizability exhibits superior NLO properties compared to theenol form of 2-HBp derivatives.

Sonochemical‐Promoted Multicomponent Synthesis of a New Amidoalkyl Naphthol Derivative Catalyzed by [(Msim)Cl] Ionic Liquid and Assessment of Its Nonlinear Optical Properties

AbstractThe sonochemical‐assisted multicomponent reaction catalyzed by ionic liquid, solvent‐free synthesis, improving chemical structure, computational calculations, and nonlinear optical properties (NLO) assessment of a new amidoalkyl naphthol derivative 4, that is, [N‐((2‐hydroxynaphthalen‐1‐yl)(4‐nitrophenyl)methyl)‐2‐phenylhydrazinecarbothioamide (C24H20N4O3S), are introduced. The corrected structure of the synthesized derivative 4 is confirmed by different spectroscopic techniques viz., (1H and 13C) NMR, Infrared radiation (IR), Mass spectra, and UV‐vis. spectra. To obtain geometrical structure and confirm the experimental findings, DFT‐assisted B3LYP/6‐31G* method is used. The NLO properties of the synthesized derivative are studied using two visible laser beams where its nonlinear refraction index (NLRI) at 473 nm cw laser beam is obtained using diffraction patterns (DPs) and the Z‐scan techniques. As high as 5.312×10−11 m2/W of NLRI is obtained. The all‐optical switching (AOS) which is usually carried out utilizing two laser beams, the controlling and controlled, is generalized by the use of three laser beams, controlling, 473 nm beam and two controlled 532 nm and 635 nm beams.

Nonlinear optical and spectroscopic properties, thermal analysis, and hemolytic capacity evaluation of quinoline-1,3-benzodioxole chalcone.

This article describes the synthesis, characterization (1H NMR, 13C NMR, FT-IR, HRMS and XRD), UV-Vis absorption and fluorescence spectra, theoretical analysis, evaluation of nonlinear optical properties (NLO), thermal analysis and determination of the hemolytic capacity of the compound (E)-N-(4-(3-(benzo[d][1,3]dioxol-5-yl)acryloyl)phenyl)quinoline-3-carboxamide (5). Radiological findings showed that compound 5 crystallized in space group Pca21. Furthermore, theoretical DFT studies performed with the B3LYP and M062X functionals showed good agreement with the experimental results and provided valuable information on the molecular and electronic structure, reactivity, polarizability, and kinematic stability of the compound. Besides, compound 5 did not show any hemolytic effect on human erythrocytes and exhibited strong NLO properties. The TG and DTA thermograms of quinoline-chalcone (5) revealed a multi-step thermal decomposition process with a total mass loss of 83.2%, including water content loss. The DTA curves exhibited endothermic peaks corresponding to decomposition steps, melting point, and thermochemical transition. Additionally, exothermic peaks in the DTA thermograms align with significant mass loss, confirming the compound's melting point and water content, as validated by X-ray diffraction analysis. These results contribute to the advancement of research on compounds with NLO properties and offer a promising avenue for the development of substances potentially applicable to optical devices in the biomedical field.

Electronic, optical and spectroscopic properties of N-dialkyl-imidazolium hexafluorophosphate (CNMIM.PF6) ionic liquid crystal molecules investigated by computational methods.

In this present work, we calculate the electronic, spectroscopic and nonlinear optical properties (NLO) of N-dialkyl-imidazolium hexafluorophosphate (CNMIM.PF6, where N = 10, 12, 14, 16, 18, 20) ionic liquid crystal molecules under the effect of alkyl chain length variation in cation moiety [CNMIM]+ with fixed anion [PF6]-. CONTEXT: The majority of research on ionic liquid crystal to date has been focused on experiments, while theoretical studies on the optical properties of ionic liquid crystal have been extremely rare. Nonlinear phenomena in optical devices have attracted many researchers. Therefore, results of NLO properties may favor facile synthesis and fabrication of novel-type of materials as well as optoelectronic devices. Spectroscopic studies elucidate further insight into ionic liquid crystal behavior. The results demonstrate that variations in alkyl chain length have an impact on the conformers' electrical, spectroscopic, and NLO properties as well as their stability. The stability of ionic liquid crystal molecules increases with increasein the alkyl chain length and the energy band gap range is 6.64-6.29 eV. Understanding ionic liquid crystal's physical behavior requires an understanding of their dipole moments and NLO features, which are covered in this article. The results of NLO characteristics for all ionic liquid crystal molecules show that their first-order hyperpolarizabilities are higher than the reference molecule (urea). METHODS: The electronic (molecular energy band gap, electrostatic potential map, as well as HOMO-LUMO orbitals) and spectroscopic (IR-RAMAN, UV) properties were evaluated with the help of theoretical model at B3LYP/6-31G(d) while the NLO study has been performed using B3LYP and M06-2X with different basis sets 6-31G(d) and 6-311++G(d,p), as implemented in Gaussian09 software.

Influence of donor-acceptor groups on the electrical and optical properties of C50 fullerene.

In this research, the C50 fullerene was employed as the source of the π electrons and the electron donor-acceptor groups were used to enhance its optical properties. Considerable enhancement in its electronic and optical property of C50 as the result of donor and acceptor group presence was observed. For instance, in UV-Visible absorption spectrum, the number of absorption lines significantly increase which may be the relaxation of the electronic transition selection rules. Considerably, the substituted forms of C50, have numbers of absorption bands in near infrared region. The BH2-C50-NCH3Li and NO-C50-NCH3Li molecules have superior improvement in optical properties. Finally, the donor and acceptor groups influence on non-linear optical properties (NLO) of C50 was explored and the considerable improvement in NLO properties of C50 was observed in which the NLO improvements for BH2-C50-NCH3Li and NO-C50-CH2Li cases is higher than others.

4-(4,5-Diphenyl-1H-imidazole-2-yl)phenol: Synthesis and Estimation of Nonlinear Optical Properties using Z-Scan Technique and Quantum Mechanical Calculations

In this study, 4-(4,5-Diphenyl-1H-imidazole-2-yl) phenol is successfully synthesized, and its nonlinear optical properties (NLO) are investigated both experimentally and theoretically. Theoretical investigations have been done by using TD-DFT and B3LYP functional with usual 6-31+G(d,p) basis set. The results of HOMO-LUMO and NBO analysis show the low energy gap, high total dipole moment, and hyperpolarizabilities (β, g) as well as the presence of dipolar excited states with relatively significant dipole-moment changes which are linked to the nonlinearity. The z-scan technique confirmed the NLO properties of title compound. The nonlinear absorption coefficient, refractive index, and third-order susceptibility were found to be 4.044 × 10-1 cmW-1, 2.89 × 10-6 cm2W-1 and 2.2627 × 10-6 esu, respectively. The negative sign of n2 indicated the occurrence of self-defocusing nonlinearity. The results show that the title compound can been used as potential NLO material.

Thiazolidine‐4‐one clubbed pyrazoles hybrids: Potent α‐amylase and α‐glucosidase inhibitors with NLO properties

AbstractMolecular hybrids based on thiazolidin‐4‐one and pyrazolyl pharmacophore (THZP) as new antidiabetic agents were synthesized. Two sets of signals came into view in 1H NMR of THZP8‐THZP14 exhibited the presence of a configurational isomeric mixture of 2E,5Z (38.24%‐41.58%) and 2Z,5Z isomers (58.42%‐61.76%), which was further endorsed by density functional theory (DFT) studies. All the compounds exhibit promising nonlinear optical properties (NLO). Further, the biological potential of THZPs was explored in terms of α‐amylase and α‐glucosidase inhibition. DFT‐based descriptors were calculated to describe the reactivity, and a relationship was developed with biological activities. THZP9 and THZP14 showed remarkable inhibition of α‐amylase and α‐glucosidase with IC50 9.90μM and 4.84μM, respectively, as compared with standard drug acarbose.

Solvent effects on non-linear optical properties (NLO) and intramolecular charge transfer (ICT) characteristics of disperse red 19 dye

The electronic absorption spectra of disperse red 19 (DR19) dye were used to calculate non-linear optical properties (NLO) and intramolecular charge transfer (ICT) characteristics in four different polarity solvents. DR19 dye shows good NLO responses with high values of NLO parameters (αCT = 1.65 × 10-23 e.s.u., βCT = 57.60 × 10-29 e.s.u. and γCT = 0.16 × 10-32 e.s.u.), in methanol medium. Then, using the NLO parameters the generalized Mulliken-Hush analysis was performed in order to evaluate the ICT characteristics responsible for the nonlinear optic character of this azo disperse red dye. The previous findings (J. Phys. Chem. A 18 (1997) 3222-3226, Song et al. [1]) and results from the present study indicate that DR19 dye is a material showing good NLO properties and that find applications in various fields.

Study the solvation effect on 6-phenyl-2-thioxo-1,2-dihydropyridine-3-carbonitrile derivatives by TD- DFT calculations and molecular dynamics simulations

The electronic structure of 6-phenyl-2-thioxo-1,2-dihydropyridine-3-carbonitrile (2-mercapto-6-phenylpyridine-3-carbonitrile) and its some derivatives have been studied both theoretically and experimentally. The choice of these compounds was motivated by their biological importance and relevance. The corresponding proposed structures of all studied derivatives in this work were confirmed by FT-IR spectrophotometer, 1HNMR spectra and XRD patterns. The Density Functional Theory (DFT) has been used to investigate the effect of substituents with different strengths of all studied compounds on the geometry structures, natural bond orbital (NBO) properties, electrostatic potential (ESP) and the global properties such as (the chemical hardness (η), global softness (S), and electronegativity (χ) by analysis of the charge distribution and extent of charge transfer in the molecule in the gas phase. Non-linear optical properties (NLO) such as (static dipole moment (μ), polarizability (α), anisotropy polarizability (Δα), first order hyperpolarizability (β) and mean second order hyperpolarizability (γ)) also, were computed by DFT in the gas and solvent (benzene and ethanol) phases. The effect of the different substitutions and solvent polarity on the NLO properties were also investigated to show their ability to be used as NLO compounds. We find that all studied compounds exhibited higher NLO properties compared to urea (reference materials) in the gas phase and showed higher NLO properties in ethanol than in the benzene phase. The effect of solvent polarity on the electronic absorption spectra of the studied molecules was measured experimentally and calculated theoretically at the Time-Dependent Density Functional Theory (TD-DFT) level of theory. The interactions of different solvents (ethanol and benzene) with studied compounds were also studied by molecular dynamics (MD) simulations. The radial distribution functions (RDFs) and coordination numbers (CNs) of all studied compounds in the different solvent are computed. The diffusion coefficient (D) also was calculated to investigate the influence of substitutions on the mobility of the studied compounds in the surrounding solvent.

Role of Zn in tuning the band gap, surface morphology, photoluminescence and optical nonlinearities of CdO nanostructures for photonic device applications

We report the role of Zn doping on third-order nonlinear optical properties (NLO) of CdO thin films. Thin Cd1−xZnxO’films’ was prepared using the spray pyrolysis (SP) technique [with x = 0, 0.01, 0.05 and 0.1 at. %] to study the morphological, surface morphology, linear optical, photoluminescence and NLO properties. The study of x-ray diffraction (XRD) revealed the crystalline nature of the prepared thin films, and the Zn-doping improves the crystallite size. The’ films morphology is mainly influenced by the’doping’shown by the images of FESEM (field emission scanning electron microscopy). As the doping concentration of Zn increases, the direct energy band-gap (Eg) value increased from 2.51 eV to 2.60 eV for undoped CdO to 10% of Zn doped CdO. Room temperature photoluminescence spectra (RTPL) of the prepared samples are investigated for an in-depth understanding of the conduction band behavior of defect states. Z-scan data showed strong’two-photon absorption’(2PA) for the deposited films and with an’increase in doping concentrations’from 0 to 10 (at %), the’nonlinear absorption coefficient (β) increasing from 1.22 × 10–4 to 4.50 × 10–4 (cmW−1), nonlinear refractive index from 7.06 × 10–9 to 1.30 × 10–8 (cm2W−1) and χ(3) i.e. third-order NLO susceptibility’values also increased from 4.03 × 10–7 to 7.31 × 10–7 (esu). Optical Limiting characteristics of the prepared films was studied at the experimental wavelength. The inspiring results of the NLO properties propose that Cd1−xZnxO thin film is an accomplished and promising material for’NLO’device applications.

Effects of Different TiO2 Particle Sizes on the Microstructure and Optical Limiting Properties of TiO2/Reduced Graphene Oxide Nanocomposites.

TiO2/reduced graphene oxide (rGO) nanocomposites with two different TiO2 particle sizes were synthesized by a facile hydrothermal method using two different source materials of Ti: tetrabutyl titanate (TBT) and commercial TiO2 powder (P25). For respective series with the same source materials, we investigated additions that optimized the nonlinear optical properties (NLO) and optical limiting (OL) performances, and we explored the relationships between structural diversity and performance. Several characterization techniques, including X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and diffuse reflectance ultraviolet-visible spectroscopy (UV-Vis) were conducted to confirm the microstructures and chemical states of as-prepared materials. This indicated the existence of the Ti–O–C bond between rGO sheets and TiO2 particles and the reduction from precursor graphene oxide (GO) to rGO. The results of UV-Vis spectra revealed that the TiO2/rGO nanocomposites showed smaller band gaps than bare TiO2. A nanosecond open-aperture Z-scan technique at 1064 nm was applied to investigate NLO and OL properties. TiO2/rGO nanocomposites exhibited enhanced NLO and OL performances, arising from synergistic effects, compared to individual components. The TBT series samples performed better than the P25 series, presumably relevant to dimensional effects.

Enhancement of Nonlinear Optical Properties of Indole Based Dyes through Electron Acceptor and π‐Linker for Dye‐Sensitized Solar Cell Applications

AbstractSix indole based thiazole substituted donor‐π‐acceptor molecules are designed and their nonlinear optical properties (NLO) are evaluated theoretically. Different electron withdrawing groups and π‐linkers are used to understand their role in tuning the NLO properties. The NLO properties of the molecules are analyzed in gas phase and in different solvent medium through the dipole moment, static polarizability, first and second hyperpolarizabilities. Efficiency of the molecules are studied through HOMO‐LUMO gap, frontier molecular orbitals, light harvesting efficiency, ionization potential, electron affinity and reorganization energy for hole and electron. All the dyes show maximum absorption wavelength in the visible region. The computed absorption spectra are well correlated with the HOMO‐LUMO gaps of the molecules. The HOMO‐LUMO gaps of all the dyes are found to be small, which lead to large NLO response. Results indicate that hyperpolarizability increases with increasing strength of the electron withdrawing group. In addition to the study of nonlinear optical property, we also calculate relevant parameters related to photovoltaic cells for two designed dyes which emerge suitable for this purpose. Photovoltaic parameters such as electron injection efficiency, exciton binding energy, and open circuit photovoltage are evaluated for dye sensitized solar cells (DSSC) applications. This study shows that alkyne π‐linkers are better than the alkene π‐linkers for desired applications. Overall, this study highlights the optical and photovoltaic nature of the dyes and reveals the influence of different π‐linkers and electron acceptors in designing new materials for NLO and DSSC applications.

Photoluminescence features and nonlinear-optical properties of the Ag0.05Ga0.05Ge0.95S2[sbnd]Er2S3 glasses

Preparation technology, the structure determination, multiband luminescence and nonlinear optical properties (NLO) of the chalcogenide glasses are subject of present work. The Ag0.05Ga0.05Ge0.95S2Er2S3 glass samples with two different 0.12 and 0.27 at.% Er content were prepared by classical two-stage melt-quenching method. Glass state and morphology were confirmed by X-ray and EDS techniques. Influence of the Erbium doping on the luminescence and NLO properties was investigated. Based on the diagram of energy levels for the Er3+ ions, we proposed a model that explains photoluminescence (PL) emission mechanism. It should be emphasized that investigated glasses (in comparison with other materials) are exceptional in that all bands of PL are intense due to small energy losses at excitation and emission of ions Er3+. The photoinduced second and third harmonic generations have been measured in the reflected geometry and compared with reference – BiB3O6 (BBO): 10%Nd crystal.

Research of the substituent effect on non-linear optical properties of bis(difluoroboron)-1,2-bis((1H-pyrrol-2-yl)methylene)hydrazine (BOPHY) derivatives: Molecular simulation analyses.

Modelling studies of bis(difluoroboron)-1,2-bis((1H-pyrrol-2-yl)methylene)hydrazine (BOPHY) derivatives were completed at M06-2X/6-31+G(d) level in vacuo. Structural properties (geometric structure, bond lengths and angles), spectral electronic properties and non-linear optical properties (NLO) of related boron complexes were investigated. Geometric parameters of mentioned boron complexes and electronic structures of them were reported. IR spectrum of boron complexes is calculated in vacuo and potential energy distribution (PED) analyses of frequencies were done. UV-VIS spectrum were calculated in gas phase (ε = 1), toluene (ε = 2.3741), chloroform (ε = 4.7113), methanol (ε = 32.613), water (ε = 78.3553) and n-methylformamide-mixture (ε = 181.56) at M06-2X/6-31+G(d), wB97X-D/6-31+G(d) and CAM-B3LYP/6-31+G(d) levels. Wavelength of observed bands in UV-VIS spectrum was used in the interpretation of optical activity. Molecular orbital energy diagram (MOED), contour diagrams of certain molecular orbitals, density of state (DOS) spectrum and molecular electrostatic potential (MEP) maps are calculated to determination of electronic properties and NLO activity. Finally, some quantum chemical descriptors were calculated and analyzed in determination of NLO properties. It is found that compound 5 and 6 are found as the good materials for NLO applications.

Structure, Reactivity, Nonlinear Optical Properties and Vibrational Study of 5-Thioxo-1,4-thiazaolidin-3-one and 5-thioxo-1,4,2-thiazasilolidin-3-one (Silicon vs. Carbon). A DFT Study

The structures and nonlinear optical properties (NLO) of 5-thioxo-1,4-thiazaolidin-3-one(Rhodanine) and 5-thioxo-1,4,2-thiazasilolidin-3-one (silarhodanine) tautomers were studied in gas phase and in solutions using the B3LYP density functional theory and composite CBS-QB3 method. The global minimum at the B3LYP/6-31++G(d,p) and CBS-QB3 levels of theory is tautomer 5 in the gas phase and in solvents for rhodanine, and simiarly, tautomer 13 is the global minimum for silarhodanine. The interconversion among the tautomers is proceeded by an intramolecular proton transfer reaction. An identical solvent effects can be noted for rhodanine and silarhodanine tautomers. The activation barrier towards ring-opening processes (1→2, 9→10) decreases with the increasing dielectric constant of the solvent; on the other hand, the barrier of the ring-closure processes (2→3, 10→11) increases with the increasing dielectric constant. The tautomers are predicted to show significant NLO properties. Also, a number of correlations between the dipole moment and electron densities in bond critical points of the S3-C4 bond and interaction energy as well as vibrational frequencies at the transition states (TS2–3,TS10–11) were examined under different solvents. Finally, the investigation of the heavy atom substitution effects on the properties of silarhodanine is proven to be very weak under these conditions.

Mono- and Diplatinum Polyynediyl Complexes as Potential Push–Pull Chromophores: Synthesis, Characterization, TD-DFT Modeling, and Photophysical and NLO Properties

This paper presents the syntheses and photophysical and the electrochemical characterizations of four new mono- and diplatinum polyynediyl complex chromophores end-capped with diphenylpyranylidene and pentafluorophenyl moieties. The nonlinear optical properties (NLO) of these compounds are investigated using the electric-field-induced second harmonic generation (EFISH) technique, and their experimental optical properties are confirmed by time-dependent density functional theory (TD-DFT) with a range-separated hybrid. All complexes show positive μβ values. While the inductive electron-withdrawing pentafluorophenyl ligand, the length of the polyyne linkers, and the number of platinum centers do not seem to significantly affect the NLO responses of these complexes, their structural configuration plays a significant role, as shown by the V-shaped complex 10 exhibiting the highest μβ value of the series of complexes, twice as high as that of the linear complex 9.

Effect of central metals and peripheral substituents on the third-order nonlinear optical properties of tetra-benzimidazole and benzothiazole substituted phthalocyanines

A series of tetra substituted phthalocyanines bearing 2-mercaptobenzimidazole or 2-mercaptobenzothiazole units with different central metals (Zn and In) were synthesized. Their photophysical properties including the parameters of fluorescence and triplet state were studied. The benzothiazole substituted phthalocyanines exhibit stronger third-order nonlinear optical properties (NLO) absorption effects, higher triplet quantum yield (ΦT) and faster intersystem crossing rate compared to the benzimidazole substituted phthalocyanines. With the same central metals, benzothiazole substituted phthalocyanine complexes have the lower fluorescence quantum yield (ΦF), the higher triplet quantum yield (ΦT) and the larger third-order NLO properties as a result of larger conjugated structure and spin-orbit coupling induced by sulphur atoms. The influences of the central metal atoms and the peripheral substituents on the third-order NLO properties are discussed using photophysical parameters.

Hydrogenated superalkalis and their possible applications.

Superalkali species possess lower ionization energy than alkali metals, which allow them to form a variety of unusual compounds with interesting properties. Herein, we report the structures and properties of hydrogenated superalkalis (SAHs) such as FLi2H, OLi3H, and NLi4H using ab initio MP2/6-311++G(d,p) level of theory. All SAH species are found to be thermodynamically stable, which can be considered as a salt between SA cation and H‾ anion. The gas phase basicity and nonlinear optical properties (NLO) of SAH have been explored. The larger proton affinity of NLi4H isomers 1187-1226kJ mol(-1) and significant mean hyperpolarizability 1.5 × 10(3)-3.7 × 10(3)a.u. suggest their strong basic nature and enhanced NLO properties, respectively. We have also demonstrated some possible applications of hydrogenated superalkalis, as reducing agent as well as building block of supersalts. Graphical abstract The gas phase basicity and nonlinear optical properties of hydogenated superalkalis increase with the increase in the size of superalkalis, FLi2 < OLi3 < NLi4.

Three novel polyoxoanion-supported compounds: confinement of polyoxoanions in Ni-containing rigid concave surfaces with enhanced NLO properties.

Three novel polyoxoanion-supported compounds modified by conjugated organic ligand tris(2-benzimidazylmethyl)amine (NTB) and nickel ions, [Ni(NTB)(H2O)]2(H2P2Mo5O23)·9.25H2O (1), [Ni(H2O)(NTB)]2(PMoMo(V)O40)·4.5H2O (2) and [Ni(NTB)]2(Mo8O26)·9H2O (3), have been successfully synthesized under hydrothermal conditions at different pH values. The compounds 1-3 contain similar rigid concave surfaces composed of [Ni(NTB)](2+) cations, which connect with different clusters to form the first examples of metal-NTB-modified polyoxoanion-supported compounds. Transition metal-containing rigid concave surfaces successfully confine polyoxoanions in compounds 1-3. In the synthesis of the three compounds, the pH values play an important role in the formation of polyoxoanions and the stability of the compounds. Additionally, the third-order nonlinear optical properties (NLO) and electrochemical behaviors were also investigated.