UV Spectra Research Articles

Vibrational and Electronic Spectroscopy of 2-Cyanoindene Cations.

2-Cyanoindene is one of the few specific aromatic or polycyclic aromatic hydrocarbon (PAH) molecules positively identified in Taurus molecular cloud-1 (TMC-1), a cold, dense molecular cloud that is considered the nearest star-forming region to Earth. We report cryogenic mid-infrared (550-3200 cm-1) and visible (16,500-20,000 cm-1, over the D 2 ← D 0 electronic transition) spectra of 2-cyanoindene radical cations (2CNI+), measured using messenger tagging (He and Ne) photodissociation spectroscopy. The infrared spectra reveal the prominence of anharmonic couplings, particularly over the fingerprint region. There is a strong CN-stretching mode at 2177 ± 1 cm-1 (4.593 μm), which may contribute to a broad plateau of CN-stretching modes across astronomical aromatic infrared band spectra. However, the activity of this mode is suppressed in the dehydrogenated (closed shell) cation, [2CNI-H]+. The IR spectral frequencies are modeled by anharmonic calculations at the B3LYP/N07D level of theory that include resonance polyad matrices, demonstrating that the CN-stretch mode remains challenging to describe with theory. The D 2 ← D 0 electronic transition of 2CNI+, which is origin dominated, occurs at 16,549 ± 5 cm-1 in vacuum (6041.8 Å in air). There are no correspondences with reported diffuse interstellar bands.

Structure of Ni(II) Inclusion Complex in Solid/Solution States and the Enhancement of Catalytic Behavior in Electrochemical Hydrogen Production.

In this article, we investigate the encapsulation of K2[Ni(maleonitriledithiolate)2] (1) within a host molecule, β-cyclodextrin (β-CD), via single-crystal X-ray analysis. An inclusion complex, K2{[Ni(maleonitriledithiolate)2]@(β-CD)2} (2), was constructed from 1 and two β-CDs. The anion guest Ni complex included a host cavity, constructed using two β-CDs, and the Ni atom of the anion was located between the two hydrophilic primary rims. Ultraviolet-visible absorption spectroscopy revealed that inclusion complex 2 exhibited a 2:1 (host:guest) stoichiometry in the solution, which is consistent with the result obtained from X-ray crystallography. The association of the host and guest occurred in two steps, and the association constants for the first and second steps were 1.1(7) × 104 and 1.8(5) × 104 mol-1 dm3, respectively. The catalytic behavior of 1 and 2 was investigated for electrochemical hydrogen production in the aqueous solution of an acetate buffer (pH = 4.72). During the catalytic reaction, inclusion complex 2 was observed to have a better catalytic reaction rate than 1. The study findings provide insights into the effects of the encapsulation of guest molecules within host structures.

Electronic Spectroscopy of the Halogenated Criegee Intermediate, ClCHOO: Experiment and Theory.

A chlorine-substituted Criegee intermediate, ClCHOO, is photolytically generated using a diiodo precursor, detected by VUV photoionization at 118 nm, and spectroscopically characterized via ultraviolet-visible (UV-vis)-induced depletion of m/z = 80 under jet cooled conditions. UV-vis excitation resonant with a π* ← π transition yields a significant ground state depletion, indicating a strong electronic transition and rapid photodissociation. The broad absorption spectrum peaks at 350 nm and is attributed to contributions from both syn (∼70%) and anti (∼30%) conformers of ClCHOO based on spectral simulations using a nuclear ensemble method. Electronic structure theory shows significant differences in the vertical excitation energies of the two conformers (330 and 371 nm, respectively) as well as their relative stabilities in the ground and excited electronic states associated with the π* ← π transition. Natural bond orbital analysis reveals significant and nonintuitive nonbonding contributions to the relative stabilities of the syn and anti conformers.

Vibronic Conical Intersection Trajectory Signatures in Wave Packet Coherences.

Conical intersections are ubiquitous in the energy landscape of chemical systems, drive photochemical reactivity, and are extremely challenging to observe spectroscopically. Using two-dimensional electronic spectroscopy, we observe the nonadiabatic dynamics in Wurster's Blue after excitation to the lowest two vibronic excited states. The excited populations relax ballistically through a conical intersection in 55 fs to the electronic ground state potential energy surface as the molecule undergoes an intramolecular electron transfer. While the kinetics are identical on both vibronic energy surfaces, we observe different patterns of coherent oscillations after traversing the conical intersection indicating distinct nonadiabatic relaxation pathways through the conical energetic funnel. These coherences are not created directly by the excitation pulses but are the result of the dynamical trajectories projecting differently on the conical intersection vibrational space. Our spectroscopic data offers a fresh perspective into the complex conical intersection topology and dynamics that emphasizes the critical involvement of the intersection space in dictating the dynamics.

Enhancing the Performance of Biodegradable Lignin Nanoparticle/PVA Composite Films via Phenolation Pretreatment of Lignin Using a Novel Ternary Deep Eutectic Solvent

As an environment-friendly biodegradable material, poly (vinyl alcohol) (PVA) has been focused on improving performance and expanding its applications. In this study, improved performance lignin nanoparticle/PVA composite film was prepared by phenolation of bagasse lignin (BL) using a novel ternary deep eutectic solvent (DES). The effects of introduction of DES-phenolated lignin (DL) nanoparticles with different additions (1, 3, 5, 10 wt%) on the properties of DL/PVA composite film were comprehensively studied by mechanical performance test, UV-shielding performance test, contact angle measurement, thermogravimetric analyses and DPPH free radical scavenging activity. The experimental results indicated that lignin nanoparticles (LNPs) were homogeneously distributed in a biodegradable PVA matrix due to hydrogen bonds between the PVA matrix and lignin nanoparticles. With the introduction of DES pretreatment on native bagasse lignin, the various performances of DL/PVA composite films, such as tensile strength, surface hydrophobicity, UV-shielding and thermal stability, were enhanced in comparison with both pure PVA film and BL/PVA composite film incorporated with DES-untreated BL. The tensile strength of DL/PVA composite film with 3 wt% addition increased to 97.79 MPa from 69.41 MPa for pure PVA film, and the water contact angle increased from 43.7° to 84.2°. DL/PVA composite film with 10 wt% addition shielded 95.8% of the UV spectrum (400–200 nm). Moreover, after incorporating the DL nanoparticles into the PVA matrix, the as-obtained DL/PVA composite films displayed good antioxidant activity by eliminating most of the DPPH free radicals. With 10 wt% addition of DL nanoparticles, the DPPH radical scavenging activity of DL/PVA composite film increased by about 76% compared with pure PVA film. These enhanced properties were attributed to the more phenolic hydroxyl groups of DL nanoparticles than of BL and the hydrogen-bonding interactions. In conclusion, the DES-phenolation pretreatment of lignin clearly improved the properties of PVA composite films. Furthermore, as both lignin and PVA are biodegradable, the lignin nanoparticle/PVA composite film may be a promising candidate for fully biodegradable robust coating materials with vital potential applications, such as UV-shielding and food packaging, etc.

High-pressure band-gap engineering and structural properties of van der Waals BiOCl nanosheets.

van der Waals BiOCl semiconductors have gained significant attention due to their excellent photochemical catalysis, low-cost and non-toxicity. However, their intrinsic wide band gap limits visible light utilization. This study explores high-pressure band-gap engineering, a "chemical clean" method, to optimize BiOCl's electronic structure. Utilizing in situ high-pressure ultraviolet-visible (UV-vis) absorption spectra, Raman spectroscopy and XRD, we systematically investigate the effects of compression on band gap and crystal structure evolution of BiOCl. Our results demonstrate that pressure efficiently narrows the band gap from 3.44 eV to 2.81 eV within the pressure range of 0.4-44 GPa. The further Raman and XRD analyses reveal an isostructural phase transition, leading to a significant change in the compressibility of the lattice parameters and bonds from anisotropic to isotropic. These findings provide a potential pathway to tune the bandgap for enhancing the photocatalytic efficiency of BiOCl.

Organometallic Ru(III) Catalysts for α-Alkylation of Carbonyl Compounds using Alcohols: Mechanistic Insights via Detection of Key Intermediates.

Three novel cyclometalated ruthenium complexes ([Ru.L(9)] [Ru.L(10)] and [Ru.L(11)]) featuring azo functionalities were synthesized and characterized using a variety of spectroscopic techniques, namely FT-IR, electronic absorption spectroscopy, and ESI-MS. Representative solid-state structures of the acquired complexes were determined through X-ray crystallography. These complexes were evidenced to be efficient catalysts for the synthesis of various α-alkylated compounds utilizing simple acetophenone derivatives with easily affordable and economically viable alcohols, which were isolated and characterized via 1H and 13C NMR spectroscopy. The optimum reaction conditions were found by employing toluene as solvent and potassium tert-butoxide as a base at 115 °C temperature utilizing 0.8 mol % of catalyst [Ru.L(10)]. The yield of the desired compounds was found to be in the range of 83-97 %. Additionally, mass spectrometry provided insights into the in-situ generated ruthenium hydride and ruthenium alkoxy intermediates, shedding light on the catalytic mechanism.

Phase-cycling and double-quantum two-dimensional electronic spectroscopy using a common-path birefringent interferometer

Ultrafast spectroscopy provides unique access to the coherent dynamics of atomic, molecular, and solid state quantum systems. A most powerful, yet experimentally challenging tool for this is two-dimensional electronic spectroscopy (2DES), allowing to isolate excitation pathways and to selectively probe coherent and incoherent couplings by controlling the phase of the ultrashort pulses that interact with the system. Its experimental implementation can in principle greatly be simplified by employing inherently phase stable birefringent in-line interferometers (TWINS), which, however, are thought to lack sufficient phase control. Here, we demonstrate an adaptation of TWINS providing full phase-cycling capabilities for 2DES. This is demonstrated by recording rephasing, non-rephasing, zero-quantum, and double-quantum 2DES on a molecular J-aggregate. This easy-to-implement extension opens up new experimental possibilities for TWINS-based 2DES in multidimensional all-optical and photoemission spectroscopy and microscopy.

Improvement of the Electrical Properties of ZnO Nanomaterials with Fe by Co-precipitation Method

Fe-doped ZnO nanomaterials were prepared by the co-precipitation method. The experiments used a solution of 0.5 M for ZnCl2, doped with FeSO4 in proportions of 0-100 wt.%, followed by the addition of 1 M for NaOH solution until a pH of 12 was reached. Next, the precipitated substances were calcinated at 550ºC for 3 h in air. SEM image analysis showed that the nanoparticles formed in the condition of pure ZnO and Fe2O3 whereas rod-shaped formed with Fe doping. Nanoparticles of ZnO transformed into nanorods when doped with Fe. EDS analysis detected Fe under the conditions of 3 and 5 wt.% doping. XRD patterns of ZnO and all doping of Fe in ZnO nanostructures were corresponded to a hexagonal wurtzite structure of ZnO which showed crystallite size in the range of 25-29 nm. The electrical properties of Fe-doped ZnO nanostructures were identified by the spectroscope measurements of fluorescence and ultraviolet-visible absorption, and the electrical conductivity was calculated. It was found that Fe doping at 3 wt.% produced the lowest energy band gap (based on spectroscopy results) and this condition was associated with the highest electrical conductivity of 0.21 x 10-3 (Ω.cm)-1 which was calculated from the measurement of electrical resistance by two probes. Therefore, Fe doping can improve the electrical properties of ZnO nanostructures.

Biosynthesis, Characterization, and Antibacterial Activity of Gold, Silver, and Bimetallic Nanoparticles Using Annona squamosa L. Leaves.

The utilization of nano-sized drug delivery systems in herbal drug delivery systems has a promising future for improving drug effectiveness and overcoming issues connected with herbal medicine. As a consequence, the use of nanocarriers as novel drug delivery systems for the improvement of traditional medicine is critical to combating infectious diseases globally. In line with this, we herein report the biosynthesis of silver nanoparticles (AgNPs), gold nanoparticles (AuNPs), and bimetallic nanoparticles (BMNPs) as antibacterial agents against pathogenic bacterial strains using Annona squamosa L. leaf extract as a bio-reductant and bio-stabilizing agent. The as-synthesized metal nanoparticles were characterized by transmission electron microscopy (TEM), ultraviolet-visible (UV-Vis) absorption spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and the dynamic light scattering (DLS) method. The as-synthesized MNPs had an average particle size of 6.98 nm ± 2.86 nm (AgNPs), 21.84 ± 8.72 nm (AuNPs), and 2.05 nm ± 0.76 nm (BMNPs). The as-synthesized AgNPs and BMNPs showed good antibacterial activity against pathogenic bacterial strains of Gram-positive Staphylococcus aureus (ATCC 25923) and Gram-negative Escherichia coli (ATCC 25922). The obtained results offer insight into the development of benign nanoparticles as safe antibacterial agents for antibiotic therapy using Annona squamosa L. leaf extract.

Photosynthetic Energy Transfer: Missing in Action (Detected Spectroscopy)?

In recent years, action-detected ultrafast spectroscopies have gained popularity offering distinct advantages over their coherently detected counterparts, such as spatially resolved and operando measurements with high sensitivity. However, there are also fundamental limitations connected to the process of signal generation in action-detected experiments. Here we perform fluorescence-detected two-dimensional electronic spectroscopy (F-2DES) of the light-harvesting II (LH2) complex from purple bacteria. We demonstrate that the B800-B850 energy transfer process in LH2 is weak but observable in F-2DES, unlike in coherently detected 2DES where the energy transfer is visible with 100% contrast. We explain the weak signatures using a disordered excitonic model that accounts for experimental conditions. We further derive a general formula for the presence of excited-state signals in multichromophoric aggregates, dependent on the aggregate geometry, size, excitonic coupling and disorder. We find that the prominence of excited-state dynamics in action-detected spectroscopy offers a unique probe of excitonic delocalization in multichromophoric systems.

Probing structural, surface morphological, optical, low temperature magnetic studies and electrochemical studies on gadolinium tellurite (GdTeO3)

Abstract Gadolinium tellurite (GdTeO3) has been synthesized by hydrothermal process. It displays both tiny nanorods and spherical particles embedded in a structure resembling flakes. Using a particle size analyzer, the size of the particle is found to be 142.5 nm. GdTeO3 has a cubic structure. Urbach energy is 0.4566 eV, energy gap is 5.797 eV, and refractive index is 1.890. The sample is suitable as UV filter and an effective applicant of optoelectronics. The bands observed in UV spectrum are assigned with the transitions between energy levels of Gd and attributed to different surface defects. The bands seen in the spectrum are linked to Gd’s energy level transitions and have various surface imperfections. The sample contained tellurite in an oxide matrix containing gadolinium. Magnetic analysis indicates that GdTeO3 may be undergoing a phase transition and may contain a small impurity. At 300 K, the M−H curve demonstrates paramagnetic and weak ferromagnetic characteristics with aligned cooperative Gadolinium spins. Pseudocapacitive behavior is shown by the cyclic voltammogram and Cp analysis. The sample exhibits 0.90 V potential window. It has been observed that specific capacitance is 139.34 Fg−1 from cyclic voltammogram and 112.93 Fg−1 from Cp analysis. Analysis of impedance reveals a pseudo-capacitive character.

Determination of the structure of a new potentially active pharmaceutical substance

Introduction. The development of methods for analyzing new potentially active pharmaceutical substances is an important part of substance standardization. An integrated approach to confirming the structure of a substance is especially important when the substance may exist in different tautomeric forms, since the properties of the substance may change depending on tautomerism, affecting, among other things, the pharmacological activity.Aim. The aim of our study was to determine the tautomeric composition of the potential active pharmaceutical substance 5-butyl-6-hydroxy-2,3-diphenylpyrimidin-4(3H)-one in solid state and solution for the subsequent development of its dosage form and determination of bioavailability.Material and methods. The object of the study was the substance 5-butyl-6-hydroxy-2,3-diphenylpyrimidin-4(3H)-one. Spectra were taken to confirm the structure: infrared on a PerkinElmer Spectrum 3 device (PerkinElmer Inc., USA) in the frequency range from 4000 to 400 cm–1, nuclear magnetic resonance 1H and 13C on a pulsed broadband spectrometer Bruker AM-500 (400 and 100 MHz) (Bruker, Germany) in DMSO-d6 solvent, ultraviolet using SF-2000 (LLC "OKB Spektr", Russia) in the wavelength range of 250–400 nm, and high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) was also carried out.Results and discussion. A feature of pyrimidine hydroxy derivatives is the presence of tautomeric forms, which can affect both the physicochemical properties of the substance and its pharmacological activity. The study found that in the solid state, 5-butyl-6-hydroxy-2,3-diphenylpyrimidin-4(3H)-one is in equilibrium between the diketo form and the enol form, and when the substance is dissolved in dimethyl sulfoxide (DMSO), the enol form is predominant. The purity was confirmed by HPLC-MS/MS.Conclusion. The structure of 5-butyl-6-hydroxy-2,3-diphenylpyrimidin-4(3H)-one was confirmed by IR and NMR spectroscopy. UV spectra were obtained, and HPLC-MS/MS was performed to exclude possible absorption of ultraviolet radiation by impurities.

Oxidative stress-induced cytotoxicity of HCC2998 colon carcinoma cells by ZnO nanoparticles synthesized from Calophyllum teysmannii

The field of green synthesis, namely using plant extracts for the production of metal nanoparticles, is rapidly gaining traction. Therefore, this study investigated the process of producing zinc oxide nanoparticles (ZnO NPs) using a water-based extract derived from the stem bark of Calophyllum teysmannii. Notably, this is the first documented utilization of this particular plant source. The presence of a distinct Ultraviolet-Visible (UV-Vis) absorption peak at 372 nm provided evidence for the creation of ZnO nanoparticles. The X-ray Diffractometer (XRD) and Field Emission Scanning Electron Microscopy (FESEM) investigations indicated that the nanoparticles exhibited sizes ranging from 31.5 to 59.9 nm and had spherical morphologies. Energy Dispersive X-ray Diffractometer (EDX) analysis verified the elemental composition of the ZnO nanoparticles, whereas the Fourier Transform Infrared (FTIR) spectra showed clear peaks, demonstrating their production. The FTIR examination of the C. teysmannii extract revealed peaks at around 3370 cm− 1, indicating the presence of phenolic compounds. These chemicals are likely responsible for the reduction and stabilization of the ZnO NPs. The high-resolution X-ray Photoelectron Spectroscopy (XPS) spectra clearly revealed separate peaks corresponding to Zn 2p and O 1s, providing confirmation of the chemical states and bonding contexts. The Raman Spectroscopy analysis revealed a distinct peak at around 425 cm⁻¹, confirming the presence of the wurtzite structure. The harmful effects of ZnO nanoparticles on HCC2998 (a kind of human colon cancer) and Vero (a type of monkey kidney epithelial) cells were evaluated using 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT), dichlorodihydrofluorescein diacetate (DCFH-DA), and boron-Dipyrromethene (BODIPY) assays. The cancer cells underwent cell death due to oxidative stress in a dose-dependent manner, as confirmed by microscopic and flow cytometry investigations.

Insights into the Metabolism, Disposition, and Quantitative Profile of mGlu5 NAM AE90015 with Metabolite Identification and a Novel Integration Method.

AE90015 is a highly specific and effective negative allosteric modulator (NAM) for the human mGlu5 receptor, showing significant promise for treating Parkinson's disease. An in vivo rat oral dose study was conducted on AE90015, which involved the collection of urine and bile samples over a 24 h period. At the study's endpoint, plasma, liver, brain, and renal tissues were also collected. A total of 30 metabolites of AE90015 were identified and structurally characterized or detected using high-resolution LC-MS/MSn. These metabolites fall into four categories: mono-hydroxyl, di-hydroxyl, mono-hydroxyl glucuronide, and di-hydroxyl glucuronide. This study provided a comprehensive overview of the metabolism, excretion, and disposition of AE90015, a promising NAM. The primary clearance pathway for AE90015 is mono-oxidation, accounting for 96% of the total, while direct excretion via renal and bile routes accounted for only 0.5%. Bile emerged as the predominant excretion route, at 65%, for metabolites and a minor amount of parent compound, which contrasts with the common assumption that urine would be the primary excretion pathway, which accounted for 26%. Each adamantyl and pyrazine moiety of AE90015 undergoes a one-time oxidation, while the pyridyl portion remains unmetabolized. Secondary metabolites, such as di-hydroxylated forms and glucuronide conjugates, do not contribute to clearance. In this work, a new quantification method combining UV and mass spectra integration was developed, allowing for the quantification of overlapping metabolite peaks. This novel approach proved to be highly effective for metabolite identification in early preclinical studies.

Synthesis of Bis(alkenyl)oligosilanes via Double Hydrosilylation and Their Structures and Photophysical Properties

AbstractA series of novel bis(alkenyl)oligosilanes was synthesized via ruthenium‐catalyzed double hydrosilylation of alkynes with dihydrooligosilanes. The structural and photophysical features of the bis(alkenyl)oligosilanes were studied by X‐ray crystallography and UV and fluorescence spectra. The functional groups on the alkenyl moieties significantly affect not only their conformation and arrangement in crystals but also the UV and fluorescence spectra.

Synthesis and characterization of multi-responsive iron oxide nanoparticles: Evaluation of antibacterial properties and photocatalytic activity

Cape gooseberry (CG) plant leaf extract-mediated iron oxide nanoparticles (CG-IO NPs) were fabricated for antibacterial research. The ideal concentration of the precursor salt, pH (11) of the reaction mixture, reducing agent to precursor salt ratio, and the production time of iron oxide nanoparticles were 5 mM, 9.0, 3:7, and 25 min, respectively. The iron oxide nanoparticles were tested using ultraviolet–visible absorption spectroscopy, photoluminescence (PL) spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric/differential thermal analysis (TG/DTA), and Fourier transform infrared (FTIR) spectroscopy. FTIR spectroscopy was used to identify functional groups of the compounds, including the carbonyl, CH, and OH bands that reduced and produced nanoparticles. The size and shape of the synthesized CG-IO NPs were determined by TEM and dynamic light scattering, with the median and mean size of 13.9 nm and 15.8 nm, respectively. The thermal stability of the synthesized CG-IO NPs was assessed using TG/DTA in a nitrogen atmosphere. The elements and oxidation states of the CG-IO NP components were examined by XPS. The luminosity of the CG-IO NP was examined using PL spectroscopy. The synthetic CG-IO NPs exhibited strong antibacterial effects against dangerous bacteria, such as Salmonella enterica (S. entirica), Escherichia coli (E. coli), Streptococcus agalactiae, and Staphylococcus aureus. CG-IO NPs assisted in water reclamation by decomposing Malachite Green dye under solar light irradiation.

A homeopathic potency transfers its water structure to aqueous ethanol without physical contact as revealed by electronic and vibrational spectroscopy

Background: A Homeopathic potency kept in contact with aqueous ethanol through water can transform the aqueous ethanol into that potency. Can a potency produce the same effect on aqueous ethanol without direct physical contact? The present experimental study addresses this question. Methods: Two potencies 30 cH and 200 cH of Thuja occidentalis in 90% EtOH were diluted with deionized and distilled (DD) water 1:100, and kept separately in two coloured 30 ml bottles. A test tube containing 90% EtOH diluted with DD water 1:100, was dipped into each of two bottles. After one hour exposure each test tube was taken out and its content aqueous ethanol was analysed by UV and FT-IR spectroscopy. The samples were also tested before one hour exposure. Baseline was set for UV spectroscopy with 90% EtOH diluted with DD water 1:100 for each experiment. Results: Spectroscopic characteristics of aqueous EtOH in each test tube after one hour exposure to a potency exactly matched those of Thuja 30 c H and Thuja 200 c H. but with higher absorption intensity. Discussion: Electromagnetic radiation (EMR) passing through a potency may carry the information of the potency and transfer it to aqueous ethanol in the test tube. Conclusion: Thuja 30 c H and Thuja 200 c H can transform water structure of aqueous ethanol into the said potencies without direct physical contact. Keywords: Homeopathic potencies, Thuja 30 c H., Thuja 200 c H., Water structure, Aqueous ethanol, Transformation, UV and FT-IR spectra.

Synthesis of a β-Nitrile-BODIPY from its β-Aldoxime Through Dehydration by Triphosgene: Comparative Spectroscopic Characterization

A high yielding (84%) transformation of a β-aldoxime-Boron dipyrromethenes (BODIPY) to its β-nitrile was achieved through a dehydration reaction employing in situ generated phosgene (from triphosgene and triethylamine). The two new organic dyes were comparatively and comprehensively characterized by 1H and 13C nuclear magnetic resonance, high-resolution mass spectrometry, infrared spectroscopy, Ultraviolet-vis absorption, and fluorescence emission spectroscopy (both steady-state and time-correlated). The significantly reduced emission and shorter excited-state lifetimes of β-oxime- BODIPY, compared to the β-nitrile derivative, were attributed to non-radiative decay processes facilitated by C=N bond isomerization in the excited state. This study highlights the effectiveness of triphosgene in facilitating the seamless, rapid conversion of the β-aldoxime to β-nitrile functionality in the model 1,3,5,7-tetramethyl-BODIPY dye under mild reaction conditions.. KEYWORDS :Aldoxime, Boron dipyrromethenes dyes, Dehydration reaction, Fluorescence, Nitrile, Phosgene.

Supersaturation Behavior: Investigation of Polymers Impact on Nucleation Kinetic Profile for Rationalizing the Polymeric Precipitation Inhibitors.

Although nucleation kinetic data is quite important for the concept of supersaturation behavior, its part in rationalizing the crystallization inhibitor has not been well understood. This study aimed to investigate the nucleation kinetic profile of Dextromethorphan HBr (as an ideal drug, BCS-II) by measuring liquid-liquid phase segregation, nucleation induction time, and Metastable Zone width. Surfeit action was examined by a superfluity assay of the drug. The concentration was scrutinized by light scattering techniques (UV spectrum (novel method) and Fluorometer (CL 53)). The drug induction time was 20 min without polymer and 90 and 110 min with polymers, such as HPMC K15M and Xanthan Gum, respectively. Therefore, the order of the polymer's ability to inhibit nucleation was Xanthan Gum > HPMC K15M in the medium (7.4 pH). Similarly, the drug induction time was 30 min without polymer and 20, 110, and 90 min with polymers, such as Sodium CMC, HPMC K15M, and Xanthan Gum, respectively. Therefore, the order of the polymer's ability to inhibit nucleation was HPMC K15M > Xanthan Gum > Sodium CMC in SIFsp (6.8 pH), which synchronizes the polymer's potentiality to interdict the drug precipitation. The HPMC K15M and xanthan Gum showed the best crystallization inhibitor effect for the maintenance of superfluity conditions till the drug absorption time. The xanthan gum is based on the "glider" concept, and this shows the novelty of this preliminary research. The screening methodology used for rationalizing the best polymers used in the superfluity formulations development successfully.