Search

This study employs femtosecond transient absorption spectroscopy to investigate the rapid dynamics of excited state carriers in three metalated porphyrin–naphthalimide (PN) molecules and one free-base molecule. The dynamics of electron injection, from PN to mesoporous titania (TiO2), in PN adsorbed TiO2 films (Ti-PN), were carefully investigated and compared to PN adsorbed ZrO2 films (Zr-PN). In addition, we examined the self-assembled PN films and found that, in their self-assembled state, these molecules exhibited a longer relaxation time than Zr-PN monomeric films, where the charge injection channel was insignificant. The ground-state bleach band in the Ti-PN films gradually shifted to longer wavelengths, indicating the occurrence of the Stark effect. Faster electron injection was observed for the metalated PN systems and the electron injection times from the various excited states to the conduction band of TiO2 (CB-TiO2) were obtained from the target model analysis of the transient absorption spectra data matrix. In these metal–organic complexes, hot electron injection from PN to CB-TiO2 occurred on a time scale of <360 fs. Importantly, Cu(II)-based PN complexes exhibited faster injection and longer recombination times. The injection times have been estimated to result from a locally excited state at ≈280 fs, a hot singlet excited state at 4.95 ps, and a vibrationally relaxed singlet excited state at 97.88 ps. The critical photophysical and charge injection processes seen here provide the potential for exploring the underlying factors involved and how they correlate with photocatalytic performance. [ABSTRACT FROM AUTHOR]

β-Heptasubstituted porphyrins [MTPP(NO2)X6; M = 2H, NiII, CuII, and ZnII; X = Br, Ph, and PE] were synthesized and their third-order nonlinear optical (NLO) properties explored using the single-beam Z-scan technique with femtosecond, MHz pulses in the visible range. The three-photon absorption (γ), thirdorder nonlinear optical susceptibility (χ³), three-photon absorption cross-section (σ3), and nonlinear refractive index (n2) have been determined from theoretical fits with experimental results. The sign and magnitude of the nonlinear refractive index (n2) have been obtained from the closed-aperture experiment while the three-photon absorption coefficient and three-photon absorption cross-section were determined from the open-aperture experiment. The magnitudes of the 3PA and σ3 extended in the range of (2.7-3.4) × 10-23 cm³ W-2 and (5.5-7.0) × 10-78 cm6 s², respectively. The higher magnitude of the NLO coefficients ensures their utility in optical and photonic applications. [ABSTRACT FROM AUTHOR]

Asymmetrically substituted porphyrins possessing ethyl acetoacetate or acetylacetone (EAA or acac) with six bromine atoms at β-positions were synthesized and then characterized by various spectroscopic techniques, such as UV-Vis, fluorescence and NMR, and also by CV, DFT, MALDI-TOF-MS and elemental analysis. The mechanistic pathway followed the nucleophilic substitution reaction (nucleophile: EAA and acac) with MTPP(NO2)Br6 (M = 2H, Cu(II), and Ni(II)), and the resultant β-heptasubstituted porphyrins exhibited keto–enol tautomerism, as supported by 1H NMR spectroscopy. The six bulky bromo and EAA/acac groups made the macrocyclic ring highly electron deficient and nonplanar such that the quantum yield and fluorescence intensity for H2TPP[EAA]Br6 and H2TPP[acac]Br6 were severely reduced in contrast to those values for H2TPP. The poor electron density and nonplanarity over the porphyrin ring shifted the first oxidation potential from 11 to 521 mV anodically for MTPP[X]Br6 [M = 2H, Cu(II), and Ni(II); X = EAA or acac] as compared to corresponding MTPPs. Notably, density functional theory proved the nonplanarity of the synthesized porphyrins as Δ24 spans from ±0.546 to ± 0.559 Å while ΔCβ stretches from ±0.973 to ±1.162 Å. The third-order nonlinear optical measurements were performed using the femtosecond pulsed laser Z-scan technique at 800 nm and 1 kHz repetition rate to acquire insights into nonlinear absorption and nonlinear refraction of the porphyrins. The three-photon absorption coefficients (γ) are in the range of 2.2 × 10−23–2.8 × 10−23 cm3 W−2 and the nonlinear refractive index values were in the range of 3.7 × 10−16–5.1 × 10−16 cm2 W−1. The higher-order nonlinear absorption exhibited by porphyrins helps improve resolution at depth for various photonic and optoelectronic applications. [ABSTRACT FROM AUTHOR]

Size-dependent perovskite nanocrystals (PNCs) have manifested tremendous improvement in nonlinear optical (NLO) studies owing to their remarkable optical and electrical properties. However, the industrialization of these materials has been circumscribed by their toxicity and instability. Attractive candidates explored to date in the quest for frontline NLO properties include organic–inorganic hybrid perovskites (OIHPs). Given the remarkable stability of the formamidinium cation (HC(NH2)2+ = FA+)) over the methylammonium cation (MA+) in hybrid perovskites, FAPbBr3 was chosen as a prototype to investigate its interactions with Sr2+ ions. Intriguingly, SrCl2-doped FAPbBr3 PNCs showed enhanced three-photon absorption (3PA) comparable/superior to some recently reported PNCs. This work paves the way for developing more stable, less toxic organic–inorganic hybrid perovskite (OIHP) PNCs for optoelectronic applications. [ABSTRACT FROM AUTHOR]

A series of three novel tetrabenzotriazacorroles (TBCs) designed with an alkyl substituent tert-butyl group (TBC-tert), an electron donor phenothiazine group (TBC-PTZ) and an energy donor carbazole group (TBC-CBZ) on the peripheral position with phosphorus metal in the cavity have been synthesized. All three compounds were characterized using various spectroscopic techniques and we assessed their femtosecond third-order nonlinear optical (NLO) properties. TBCs exhibit the properties of both phthalocyanines and corroles as they are derived from parent phthalocyanines. The optical studies revealed a new band at ∼450 nm, which was absent in the parent phthalocyanine molecules, and all three compounds obeyed Beer–Lambert's law. Singlet-state quantum yields were measured in different solvents and were found to be in the range of 0.3 to 0.6 for TBC-tert , 0.21 to 0.25 in the case of TBC-PTZ and 0.31 to 0.41 for TBC-CBZ. Time-resolved fluorescence studies revealed lifetimes in the ns regime (typically few ns). The redox properties of the TBCs suggest that they are easier to oxidize and harder to reduce and exhibit multiple oxidation and reduction potentials. Using the Z-scan technique, the third-order NLO properties were investigated with kilohertz and megahertz repetition rate femtosecond pulses at 800 nm. We report the first observation of strong three-photon absorption in these molecules with coefficients of ∼10−22 cm3 W−2 (∼10−13 cm3 W−2) with kHz (MHz) repetition rate fs pulse excitation. [ABSTRACT FROM AUTHOR]

A new series of "push–pull" meso-substituted trans-A2BC porphyrins, where A = mesityl, B = phenothiazine (push) and C = o/p-nitrophenyl moiety (pull) and M = 2H, Ni(II), Cu(II), and Zn(II), were synthesized. These trans-A2BC porphyrins were characterized by various techniques viz. UV-Vis, fluorescence and NMR spectroscopy, matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry, cyclic voltammetry, single-crystal X-ray diffraction analysis and density functional theory (DFT) studies. The single crystal structure of the newly synthesized free base trans-H2A2BC porphyrin (2) revealed the orientation of meso-substituents and the planar conformation of the porphyrin core. All newly synthesized free base trans-H2A2BC porphyrins (1 or 2) and their metal complexes exhibited a sharp Soret band. The first reduction potential of all synthesized trans-MA2BC porphyrins showed an anodic shift as compared with that of meso-tetraphenylporphyrins (MTPPs) due to the strong electron withdrawing nature of the nitrophenyl group. In general, the first oxidation potential of trans-MA2BC porphyrins shows a cathodic shift due to the electron donating phenothiazine moiety as compared to that of MTPPs. p-Nitrophenyl appended trans-A2BC porphyrins exhibited large ground state dipole moment values (8.59–9.64 D) as compared to MTPPs (0.0013–0.052 D) owing to the polarized "push–pull" effect of meso-substituents such as phenothiazine (push) and nitrophenyl (pull) moieties. Femtosecond nonlinear optical (NLO) studies performed with kHz pulses at 800 nm revealed strong two-photon absorption coefficients (∼0.082–0.0953 cm GW−1) and cross-sections (∼1.71–1.95 × 103 GM) for these "push–pull" porphyrins. We have also attempted to understand the NLO coefficients in terms of the structural changes in these porphyrin derivatives. A comparison that has been accomplished with similar porphyrin molecules and under similar experimental conditions revealed the superior performance of the title molecules. Furthermore, femtosecond transient absorption studies demonstrated several ultrafast processes from various excited states in these porphyrins, useful for identifying the processes relevant to optical switching applications. [ABSTRACT FROM AUTHOR]

In the light of diverse applications of nonlinear optical (NLO) chromophores in interdisciplinary fields, there is high demand for the quest of cost-effective and facile processing of smart materials. To narrow down such potential sensitizers, a profound physical understanding of the structure–property relationship is the need of the hour. The new molecular designs have triggered the development of simple carbazole scaffold dyes with D–π–A configurations, which can act as NLO chromophores. The theoretical and experimental frameworks of these novel molecular-engineered dyes exhibited strong charge-transfer absorption bands in the visible region besides high extinction coefficients and appropriate redox properties, making them promising canditates for NLO devices. Notably, the substitution of π-linkers and the insertion of the azo group on carbazole is critical for the optimal optoelectronic window, as evidenced by the spectral, electrochemical experiments, and density functional theory calculations. The state-of-the-art femtosecond (fs) Z-scan studies unveiled a strong third-order NLO susceptibility of ∼10−12 esu. Intriguingly, these dyes also exhibited reversible saturable absorption (RSA) kind of behavior when excited at 800 nm due to two-photon absorption (2PA), further augmenting them as alluring candidates for NLO device applications. The strong 2PA cross-sections [362–1890 GM] obtained for these molecules propitiously augur well for bio-imaging and other photonic applications. [ABSTRACT FROM AUTHOR]

Two new series of β-triphenylamine-appended porphyrins (MTPP(TPA)2X, (where M = 2H, Co(II), Ni(II), Cu(II), Zn(II) and X = NO2/CHO) have been synthesized and characterized by various spectroscopic techniques, namely, UV-vis, fluorescence, NMR spectroscopy, mass spectrometry, cyclic voltammetry, density functional theory and ultrafast nonlinear optical (NLO) studies. They exhibited 16–22 nm and 39–58 nm red-shifts in the Soret and Qx(0,0) bands, respectively, as compared to MTPPs due to the resonance and inductive effects of β-substituents on the porphyrin π-system. The first reduction potential of CuTPP(TPA)2NO2 and CuTPP(TPA)2CHO exhibited an anodic shift by 0.44 and 0.36 V, respectively, as referenced to CuTPP, due to the electronic nature of β-substituents (NO2 and CHO), which led to their easier reduction compared with CuTPP. H2TPP(TPA)2NO2 and H2TPP(TPA)2CHO exhibited the largest resultant dipole moments (7.66 D and 4.55 D, respectively) as compared to H2TPP (0.052 D) due to the cross-polarized push–pull effect of β-substituents (NO2/CHO and triphenylamino groups) and the nonplanarity of the macrocyclic core. Third-order nonlinear optical properties of MTPP(TPA)2NO2 and MTPP(TPA)2CHO (M = 2H and Zn(II)) were investigated in a broad spectral range (680–850 nm) using the Z-scan technique with femtosecond 80 MHz pulses. These materials demonstrate strong nonlinear optical coefficients, endowing them with potential for prominent photonic applications. [ABSTRACT FROM AUTHOR]

Surface enhanced Raman spectroscopy (SERS) is a cutting edge analytical tool for trace analyte detection due to its highly sensitive, non-destructive and fingerprinting capability. Herein, we report the detection of multiple analytes from various mixtures using gold nanoparticles (NPs) and nanostructures (NSs) as SERS platforms. NPs and NSs were achieved through the simple approach of laser ablation in liquids (LAL) and their morphological studies were conducted with a UV-Visible absorption spectrometer, a high resolution transmission electron microscope (HRTEM) and a field emission scanning electron microscope (FESEM). The fabricated NPs/NSs allowed the sensitive and selective detection of different mixed compounds containing (i) rhodamine 6G (Rh6G) and methylene blue (MB), (ii) crystal violet (CV) and malachite green (MG), (iii) picric acid (explosive) and MB (dye), (iv) picric acid and 3-nitro-1,2,4- triazol-5-one (explosive, NTO) and (v) picric acid and 2,4-dinitrotoluene (explosive, DNT) using a portable Raman spectrometer. Thus, the obtained results demonstrate the capability of fabricated SERS substrates in identifying explosives and dyes from various mixtures. This could pave a new way for simultaneous detection of multiple analytes in real field applications. [ABSTRACT FROM AUTHOR]

In the present work, we have effectively utilised the reducing/capping ability of polyvinylpyrrolidone (PVP, 40 000 molecular weight) for the versatile synthesis of various anisotropically shaped (hexagonal, triangle, decahedral and star) gold nanostructures. Controllable size, shape and stability of the nanoparticles (NPs) were achieved by merely changing the surrounding reaction media (such as water, alcohol, DMF etc.). It has been well-established that variations in the inherent chemical structure of the polymer, PVP, in different solvents essentially play a crucial role in the stabilisation of these as-synthesized Au NPs. In particular, for the star-shaped Au NPs, the core size, tip length and the number of tips were effortlessly controlled using different molar ratios of PVP to Au metal ions under varying pH of the reaction medium. The corresponding localised surface plasmon resonance (LSPR) peaks of these different Au NPs were broadly tunable right from the visible to the near-infrared (NIR) region. Also, all our as-prepared Au NPs are shown to be enhanced refractive index sensors by way of their linearly increased LSPR stability with the dielectric constant of the surrounding media. Further, the higher number of sharp tips and the highest tip-to-core ratio of star-shaped Au NPs demonstrate excellent performance both in catalysis and surface-enhanced Raman scattering (SERS) activities. An excellent catalytic rate constant and a SERS enhancement factor as high as ∼109 are evaluated from detailed, careful studies and established from the comparative performance analysis of our present Au NPs. [ABSTRACT FROM AUTHOR]

Triarylboron compounds have been established as promising candidates in optoelectronic applications. However, realizing multi-functional properties in triaryl boron-based materials remains challenging. Herein, we present two regioisomers, 1 and 2, designed judiciously by connecting a dimethylamino donor and a dimesitylboryl acceptor at 1,4 and 2,6-positions of the naphthalene spacer, respectively. Both compounds 1 and 2 display simultaneous, delayed fluorescence and persistent room-temperature phosphorescence (580 nm, τ av = 168 ms, Φ = 76% for 1; 550 nm, τ av = 129 ms, Φ = 88% for 2 in 1 wt% PMMA), with the delayed fluorescence bands being sensitive to doping concentration (in PMMA). Notably, compound 1 in 1 wt% PMMA films demonstrates a reversibly switchable single-molecule phosphorescence from orange (580 nm) to green ( λ Ph = 550 nm, τ av = 42 ms) in response to pH, which can be utilized for anti-counterfeiting applications. These results were further corroborated by studying the respective cationic salts 1-OTF and 2-OTF. Moreover, 1 and 2 exhibited blue-shifted fluorescence in response to mechanical pressure. Compound 2 also showed three-photon (σ3P) absorption properties which were better compared to those of compound 1., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Plasmonic nanoparticles (NPs) have played a significant role in the evolution of modern nanoscience and nanotechnology in terms of colloidal synthesis, general understanding of nanocrystal growth mechanisms, and their impact in a wide range of applications. They exhibit strong visible colors due to localized surface plasmon resonance (LSPR) that depends on their size, shape, composition, and the surrounding dielectric environment. Under resonant excitation, the LSPR of plasmonic NPs leads to a strong field enhancement near their surfaces and thus enhances various light-matter interactions. These unique optical properties of plasmonic NPs have been used to design chemical and biological sensors. Over the last few decades, colloidal plasmonic NPs have been greatly exploited in sensing applications through LSPR shifts (colorimetry), surface-enhanced Raman scattering, surface-enhanced fluorescence, and chiroptical activity. Although colloidal plasmonic NPs have emerged at the forefront of nanobiosensors, there are still several important challenges to be addressed for the realization of plasmonic NP-based sensor kits for routine use in daily life. In this comprehensive review, researchers of different disciplines (colloidal and analytical chemistry, biology, physics, and medicine) have joined together to summarize the past, present, and future of plasmonic NP-based sensors in terms of different sensing platforms, understanding of the sensing mechanisms, different chemical and biological analytes, and the expected future technologies. This review is expected to guide the researchers currently working in this field and inspire future generations of scientists to join this compelling research field and its branches.

β-Heptasubstituted porphyrins [MTPP(NO 2 )X 6 ; M = 2H, Ni II , Cu II , and Zn II ; X = Br, Ph, and PE] were synthesized and their third-order nonlinear optical (NLO) properties explored using the single-beam Z -scan technique with femtosecond, MHz pulses in the visible range. The three-photon absorption ( γ ), third-order nonlinear optical susceptibility ( χ 3 ), three-photon absorption cross-section ( σ 3 ), and nonlinear refractive index ( n 2 ) have been determined from theoretical fits with experimental results. The sign and magnitude of the nonlinear refractive index ( n 2 ) have been obtained from the closed-aperture experiment while the three-photon absorption coefficient and three-photon absorption cross-section were determined from the open-aperture experiment. The magnitudes of the 3PA and σ 3 extended in the range of (2.7-3.4) × 10 -23 cm 3 W -2 and (5.5-7.0) × 10 -78 cm 6 s 2 , respectively. The higher magnitude of the NLO coefficients ensures their utility in optical and photonic applications.

Asymmetrically substituted porphyrins possessing ethyl acetoacetate or acetylacetone (EAA or acac) with six bromine atoms at β-positions were synthesized and then characterized by various spectroscopic techniques, such as UV-Vis, fluorescence and NMR, and also by CV, DFT, MALDI-TOF-MS and elemental analysis. The mechanistic pathway followed the nucleophilic substitution reaction (nucleophile: EAA and acac) with MTPP(NO 2 )Br 6 (M = 2H, Cu(II), and Ni(II)), and the resultant β-heptasubstituted porphyrins exhibited keto-enol tautomerism, as supported by 1 H NMR spectroscopy. The six bulky bromo and EAA/acac groups made the macrocyclic ring highly electron deficient and nonplanar such that the quantum yield and fluorescence intensity for H 2 TPP[EAA]Br 6 and H 2 TPP[acac]Br 6 were severely reduced in contrast to those values for H 2 TPP. The poor electron density and nonplanarity over the porphyrin ring shifted the first oxidation potential from 11 to 521 mV anodically for MTPP[X]Br 6 [M = 2H, Cu(II), and Ni(II); X = EAA or acac] as compared to corresponding MTPPs. Notably, density functional theory proved the nonplanarity of the synthesized porphyrins as Δ24 spans from ±0.546 to ± 0.559 Å while Δ C β stretches from ±0.973 to ±1.162 Å. The third-order nonlinear optical measurements were performed using the femtosecond pulsed laser Z -scan technique at 800 nm and 1 kHz repetition rate to acquire insights into nonlinear absorption and nonlinear refraction of the porphyrins. The three-photon absorption coefficients ( γ ) are in the range of 2.2 × 10 -23 -2.8 × 10 -23 cm 3 W -2 and the nonlinear refractive index values were in the range of 3.7 × 10 -16 -5.1 × 10 -16 cm 2 W -1 . The higher-order nonlinear absorption exhibited by porphyrins helps improve resolution at depth for various photonic and optoelectronic applications.

A series of three novel tetrabenzotriazacorroles (TBCs) designed with an alkyl substituent tert -butyl group (TBC-tert), an electron donor phenothiazine group (TBC-PTZ) and an energy donor carbazole group (TBC-CBZ) on the peripheral position with phosphorus metal in the cavity have been synthesized. All three compounds were characterized using various spectroscopic techniques and we assessed their femtosecond third-order nonlinear optical (NLO) properties. TBCs exhibit the properties of both phthalocyanines and corroles as they are derived from parent phthalocyanines. The optical studies revealed a new band at ∼450 nm, which was absent in the parent phthalocyanine molecules, and all three compounds obeyed Beer-Lambert's law. Singlet-state quantum yields were measured in different solvents and were found to be in the range of 0.3 to 0.6 for TBC-tert, 0.21 to 0.25 in the case of TBC-PTZ and 0.31 to 0.41 for TBC-CBZ. Time-resolved fluorescence studies revealed lifetimes in the ns regime (typically few ns). The redox properties of the TBCs suggest that they are easier to oxidize and harder to reduce and exhibit multiple oxidation and reduction potentials. Using the Z -scan technique, the third-order NLO properties were investigated with kilohertz and megahertz repetition rate femtosecond pulses at 800 nm. We report the first observation of strong three-photon absorption in these molecules with coefficients of ∼10 -22 cm 3 W -2 (∼10 -13 cm 3 W -2 ) with kHz (MHz) repetition rate fs pulse excitation.

A new series of "push-pull"meso-substituted trans-A 2 BC porphyrins, where A = mesityl, B = phenothiazine (push) and C = o/p-nitrophenyl moiety (pull) and M = 2H, Ni(ii), Cu(ii), and Zn(ii), were synthesized. These trans-A 2 BC porphyrins were characterized by various techniques viz. UV-Vis, fluorescence and NMR spectroscopy, matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry, cyclic voltammetry, single-crystal X-ray diffraction analysis and density functional theory (DFT) studies. The single crystal structure of the newly synthesized free base trans-H 2 A 2 BC porphyrin (2) revealed the orientation of meso-substituents and the planar conformation of the porphyrin core. All newly synthesized free base trans-H 2 A 2 BC porphyrins (1 or 2) and their metal complexes exhibited a sharp Soret band. The first reduction potential of all synthesized trans-MA 2 BC porphyrins showed an anodic shift as compared with that of meso-tetraphenylporphyrins (MTPPs) due to the strong electron withdrawing nature of the nitrophenyl group. In general, the first oxidation potential of trans-MA 2 BC porphyrins shows a cathodic shift due to the electron donating phenothiazine moiety as compared to that of MTPPs. p-Nitrophenyl appended trans-A 2 BC porphyrins exhibited large ground state dipole moment values (8.59-9.64 D) as compared to MTPPs (0.0013-0.052 D) owing to the polarized "push-pull" effect of meso-substituents such as phenothiazine (push) and nitrophenyl (pull) moieties. Femtosecond nonlinear optical (NLO) studies performed with kHz pulses at 800 nm revealed strong two-photon absorption coefficients (∼0.082-0.0953 cm GW -1 ) and cross-sections (∼1.71-1.95 × 10 3 GM) for these "push-pull" porphyrins. We have also attempted to understand the NLO coefficients in terms of the structural changes in these porphyrin derivatives. A comparison that has been accomplished with similar porphyrin molecules and under similar experimental conditions revealed the superior performance of the title molecules. Furthermore, femtosecond transient absorption studies demonstrated several ultrafast processes from various excited states in these porphyrins, useful for identifying the processes relevant to optical switching applications.

Two new series of β-triphenylamine-appended porphyrins (MTPP(TPA) 2 X, (where M = 2H, Co(ii), Ni(ii), Cu(ii), Zn(ii) and X = NO 2 /CHO) have been synthesized and characterized by various spectroscopic techniques, namely, UV-vis, fluorescence, NMR spectroscopy, mass spectrometry, cyclic voltammetry, density functional theory and ultrafast nonlinear optical (NLO) studies. They exhibited 16-22 nm and 39-58 nm red-shifts in the Soret and Q x (0,0) bands, respectively, as compared to MTPPs due to the resonance and inductive effects of β-substituents on the porphyrin π-system. The first reduction potential of CuTPP(TPA) 2 NO 2 and CuTPP(TPA) 2 CHO exhibited an anodic shift by 0.44 and 0.36 V, respectively, as referenced to CuTPP, due to the electronic nature of β-substituents (NO 2 and CHO), which led to their easier reduction compared with CuTPP. H 2 TPP(TPA) 2 NO 2 and H 2 TPP(TPA) 2 CHO exhibited the largest resultant dipole moments (7.66 D and 4.55 D, respectively) as compared to H 2 TPP (0.052 D) due to the cross-polarized push-pull effect of β-substituents (NO 2 /CHO and triphenylamino groups) and the nonplanarity of the macrocyclic core. Third-order nonlinear optical properties of MTPP(TPA) 2 NO 2 and MTPP(TPA) 2 CHO (M = 2H and Zn(ii)) were investigated in a broad spectral range (680-850 nm) using the Z-scan technique with femtosecond 80 MHz pulses. These materials demonstrate strong nonlinear optical coefficients, endowing them with potential for prominent photonic applications.