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- electropolymerization
- polyporphyrin films
- quartz crystal microbalance method
- oxygen electroreduction.
- supercontinuum generation
- Nonlinear
- photonic crystal fiber taper
- Applied Chemistry
- Optoelectronic Information Science and Engineering
- Beijing University of Posts and Telecommunications (BUPT)
- G.A. Krestov Institute of Solution Chemistry of RAS
- University Union Nicola Tesla
- Ivanovo State University of Chemistry and Technology
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Synthesis and photoluminescence properties of different structural cuprous complexes regulated by benzoxazole ligands and halogen/pseudohalide ions
摘要： Reaction of 2-(2’-pyridyl)benzoxazole (2-PBO), 2-(4’-pyridyl)benzoxazole (4-PBO) and 2,2-(1,4-butanediyl)bis-1,3-benzoxazole (BBO) ligands with CuX (X = I, Br, SCN) afforded a binuclear copper(I) complex [Cu(2-PBO)(μ2-I)]2 (1) and three copper(I) coordination polymers [Cu4(4-PBO)4(μ3-I)4]n (2), {[Cu(4-PBO)(μ3-SCN)]2}n (3) and {[Cu(BBO)(μ2-Br)]2}n (4). The structural analysis revealed that the all copper(I) ions are four-coordinated and the geometric structure around the central copper(I) atom possessing slightly distorted tetrahedral geometry in complexes 1-4. Halogen or pseudohalide ions can not only act as counter anions, but also as ligands participation in coordination when the cuprous ion coordination sites are not saturated. Due to the different coordination modes of the benzoxazole ligands, in order to satisfy the tetra-coordination of cuprous ions, halogen or pseudohalide ions adopt μ2 and/or μ3-bridging modes to synergistically complete coordination. Photoluminescence investigation show that complexes 1, 3 and 4 have two emission peaks, the high energy band peak is attributed to MLCT[d10(Cu)→π*] and XMCT, the low energy band peak is caused by the 3CC emission. This may be due to the presence of μ2-X (X=I, Br, S) in these complexes. However complex 2 only had one emission peak, which may be attributed to MLCT[d10(Cu)→π*] and XMCT.
关键词： Cuprous complex,Charge-transfer,Photoluminescence,Crystal structure,Benzoxazole
更新于2025-09-23 15:23:52
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A triple alkoxo bridged dinuclear cobalt(III) complex mimicking phosphatase and showing ability to degrade organic dye contaminants by photocatalysis
摘要： A dinuclear cobalt(III) complex, [(N3)L1CoIIIL2CoIIIL1] (1), has been synthesized and characterized {H2L1 = 2-((1-hydroxybutan-2-ylimino)methyl)-4-bromophenol and HL2 = 2-amino-1-butanol}. Single crystal X-ray diffraction analysis confirmed its structure. Extended supra-molecular architectures were generated in the complex through weak noncovalent interactions. The energetic features of significant supramolecular interactions have been investigated using DFT calculation and further corroborated with NCI plot index computational tool. The complex has been found to mimic the role of phosphatase enzyme efficiently by transforming 4-nitrophenylphosphate to 4-nitrophenolate at room temperature. The reaction follows Michaelis–Menten enzymatic reaction kinetics with turnover numbers of ~1.4 s-1 in aqueous DMF (98% DMF, v/v) medium. The complex also acts as an efficient photocatalyst for degradation of organic pollutants. Methylene blue (MB), a widely used dye in various industries, was selected as a model pollutant in aqueous media to evaluate the photocatalytic effectiveness of the complex.
关键词： DFT calculation,phosphatase mimicking activity,Photocatalytic degradation of methylene blue (MB),Cobalt(III),Crystal structure
更新于2025-09-23 15:23:52
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A microporous Tb-MOF luminescent sensor based on a flexible tricarboxylate for highly sensitive detection of acetone and Fe3+ ions in aqueous and isopropanol
摘要： One novel microporous terbium (III) framework, [Tb(DBB)(H2O)2](1), has been prepared from 4-(3,5-dicarboxylatobenzyloxy) benzoic acid (DBB) with terbium salt under hydrothermal condition. Structural analysis shows complex 1 possesses three-dimensional frameworks based on 2D double sheets linking by DBB ligands into porous channels. The gas adsorption experiments of N2 and CO2 show that complex 1 possesses microporous properties. Fluorescence analyses exhibit the characteristic luminescence of Tb3+ ion both in solid state and in aqueous. In particular, the Tb-MOF can detect acetone for its luminescence entirely quenching in acetone. Furthermore, the ionic detection experiments indicate complex 1 could be a good sensor for highly and sensitively sensing Fe3+ ion in aqueous and isopropanol, and the detection limit could reach at 10?9 M in aqueous.
关键词： The microporous Tb-framework,Luminescent sensor for acetone and Fe(III) ion,Crystal structure
更新于2025-09-23 15:23:52
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Enhancing Diamond NV Center Density in HPHT Substrate and Epitaxy Lateral Overgrowth Layer by Tungsten Pattern
摘要： The Nitrogen Vacancy (NV) center distribution in epitaxial lateral overgrowth (ELO) single crystal diamond layer grown on tungsten patterned HPHT substrate by microwave plasma chemical vapor deposition (CVD) system has been investigated. It has been found that in ELO diamond layer densities of NV0 and NV- center above the tungsten metal are enhanced. Meanwhile, in patterned high-pressure and high-temperature (HPHT) substrate the density of NV- center beneath the tungsten metal is much higher than that of NV0. The HPHT substrate doesn't contain NV centers before CVD growth, and there is almost no NV center in the region without tungsten metal after growth.
关键词： Defects,Carbon materials,Epitaxial growth,Luminescence,Crystal growth
更新于2025-09-23 15:23:52
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Identification and structures of the X-ray induced luminescence centers in the zeolites Zr,X,Cs,Na-LTA, X = Cl, Br, and I
摘要： Zr4+ and halide anions were introduced into zeolite A (LTA) by treating Cs,Na-A with ZrX4(g), X = Br and I, under anhydrous conditions. The crystal structures of Zr,Br,Cs,Na-A and Zr,I,Cs,Na-A were determined by single-crystal crystallography with compositional confirmation by scanning electron microscopy energy-dispersive X-ray (SEM-EDX) analysis. Their X-ray induced luminescence (XIL) properties were thoroughly studied. These structures and XIL properties were compared with those of previously reported Zr,Cl,Cs,Na-A. In both structures, most Na+ and Cs+ ions occupy positions similar to those found in Cs,Na-A and Zr,Cl,Cs,Na-A. About 9% of the large cavities of Zr,Br,Cs,Na-A are centered by ZrBr6 2- ions. In Zr,I,Cs,Na-A, about 6% are centered by ZrI6 2-. These octahedral ZrX6 2- ions are each held in place and stabilized in their large cavities by 24 bonds between all six of its halide ions and eight surrounding Cs+ ions. They are further bridged by 8-ring Cs+ ions to form a cubic 3-dimensional Cs11ZrX6 9+ continuum in the surface volume of the crystal. Their XIL domain peaks have red-shifted from 495 nm for Zr,Cl,Cs,Na-A, to 520 nm for Zr,Br,Cs,Na-A, and to 640 nm for Zr,I,Cs,Na-A. This may be because the self-trapped excitons (STE) of ZrBr6 2- and ZrI6 2- have smaller band gaps than that of ZrCl6 2-, a result of the valence band maximum 4p energy level in Br- being higher (5p in I- even higher) than the 3p energy level in Cl-.
关键词： ZrBr6 2- and ZrI6 2-,Crystal structure,Extraframework Zr4+,Luminescence,Zeolite A
更新于2025-09-23 15:23:52
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Synthesis, crystal structures, second harmonic generation response and temperature phase transitions of two noncentrosymmetric Cu(II)-hybrid halides compounds: [(R)-C7H16N2][CuX4] (X?= Cl or Br)
摘要： (R)-(+)-3-aminoquinuclidine was used in the synthesis of [(R)-C7H16N2][CuCl4] (1) and [(R)-C7H16N2][CuBr4] (2), which both contain similar [CuX4]2- anions (X = Cl or Br). The structures of the two compounds were determined using single-crystal X-ray diffraction. The use of enantiomerically pure sources of (R)-C7H14N2 forces crystallographic noncentrosymmetry. These materials crystallize in the chiral space group P212121 (No. 19), which exhibits the enantiomorphic crystal class 222 (D2). In the molecular arrangement, the [CuX4]2- anions are linked to the organic cations through N-H...X and C-H...X hydrogen bonds to form cation-anion-cation molecular units, which are held together by means of offset face-to-face interactions giving a three-dimensional network. Thermal stability of the crystals was ascertained by TG measurement. Compounds (1) and (2) display several phases transition with higher transition temperature at T = 100°C. The Kurtz and Perry powder method using Nd:YAG laser shows that their second harmonic generation (SHG) efficiencies are about 0.81 and 0.82 times as large as that of KH2PO4 (KDP), respectively. Such a chiral hybrid metal halides skeleton could provide a new platform for future engineering in the areas including information storage, light modulators and optoelectronic functionalities.
关键词： nonlinear optics,second harmonic generation,crystal structure,chiral hybrid halide,phase transitions
更新于2025-09-23 15:23:52
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A nonlinear photonic crystal fiber for liquid sensing application with high birefringence and low confinement loss
摘要： This paper presents a nonlinear Photonic Crystal Fiber (PCF) based sensor to detect liquid analytes. An extensive analysis has been presented at wide range of wavelength (0.6 μm?1.6 μm) in order to investigate the impact of some design parameters. The numerical investigation has been done using the full vector Finite Element Method (FEM). The proposed model provides an outstanding nonlinear coefficient value with high birefringence, high sensitivity, and low confinement loss. The designed model can be used in sensing and bio-sensing research and their applications.
关键词： Effective Area,Sensitivity,Nonlinearity,Confinement loss,Photonic Crystal Fiber,Birefringence
更新于2025-09-23 15:23:52
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Fracture strength of silicon torsional mirror resonators fully coated with submicrometer-thick PECVD DLC film
摘要： In this work, we attempted to enhance the torsional fracture strength of single crystal silicon (SCS) resonators for micro mirrors application by introducing a 300 nm-thick diamond-like carbon (DLC) coating. The SCS torsional beams of the resonators were 20 μm wide and 9 μm thick, and fully coated with DLC films using plasma enhanced chemical vapor deposition (PECVD) at three different deposition bias voltages. The resonators were driven by a piezoelectric actuator and their angular amplitude was measured by a custom-made torsional test system. Average nominal torsional fracture strength of DLC coated resonators was 11.1–30.0% higher than that of bare SCS, reaching a value of 2.93 GPa. The torsional fracture strength of resonators exhibited a good agreement with the tensile fracture strength. Deviations in torsional strength were reduced with increasing deposition bias voltage due to the compressive residual stress of DLC films.
关键词： Single crystal silicon,Micro mirror resonator,Diamond-like carbon film,Strength deviation,Torsional fracture strength
更新于2025-09-23 15:23:52
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Reduction and compensation of humidity measurement errors at cold temperatures using dual QCM humidity sensors based on graphene oxides
摘要： One of the difficulties in measurements of relative humidity in a variety of environments is temperature-dependence especially at cold temperatures. Here, we report on the reduction and the compensation of temperature effects on humidity measurements using dual humidity sensors based on quartz crystal microbalance (QCM). Graphene oxide film is coated on quartz crystals as a humidity sensing layer for the detection of water sorption by the change of resonance frequency. Relative humidity in a test chamber, where dual QCM humidity sensors are located, is precisely controlled using a humidity generator at the temperature range from 20 °C to ?60 °C. It is found that single QCM humidity sensors measure humidity significantly higher than reference relative humidity by the generator as temperature is lowered due to the temperature-dependent resonance of quartz crystals. In an attempt to cancel out the temperature-dependent oscillation of QCM sensors, the ratio of resonance frequencies of dual QCM humidity sensors is used. Consequently, temperature-dependent errors in humidity measurement at low temperatures are evidently reduced. For the compensation of the remaining errors in the humidity measurement by dual QCM humidity sensors, a single formula is empirically obtained. After the compensation of low temperature effects, the dual QCM humidity sensors provide the measurement capability in terms of residual errors less than 1.1%rh throughout temperatures from 20 °C to ?60 °C. This study provides a useful insight to extend the applicability of QCM-based humidity sensors to environments with cold temperatures.
关键词： Compensation,Graphene oxide,Cold temperature,Quartz crystal microbalance,Humidity measurement,Humidity sensor
更新于2025-09-23 15:23:52
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Shining light on growth-dependent surface chemistry of organic crystals: a polarised Raman spectroscopic and computational study of aspirin
摘要： Understanding and controlling crystal surfaces is a critical problem in contemporary materials science. Organic crystal surfaces present the additional complexity of multiple terminations with different functional groups. These alternate terminations influence the surface chemistry and exert control on many material properties. While established tools for surface characterization exist, few provide the chemical information required to unambiguously identify functional groups. Polarized Raman spectroscopy is a versatile tool that can provide detailed chemical information on molecular materials, and, when used in a microscope configuration, can be used to map substrates on a micron scale. In this work, we demonstrate the use of polarized Raman to study the surface chemistry of aspirin. By analyzing crystals grown under a variety of conditions, we relate the growth solvent to the surface termination and reconcile the conflicting results in the literature on the nature of the <100> surface. Our results are supported by detailed first-principles modelling of the surfaces and their vibrational spectra. This study establishes the potential of polarized Raman microscopy as a tool for organic surface science that, when combined with predictive modelling, provides a powerful means to understand and ultimately control surface chemistry.
关键词： aspirin,first-principles modelling,crystal growth,polarized Raman spectroscopy,surface termination,lattice dynamics
更新于2025-09-23 15:23:52