UV-Vis Spectrum and the Third-order Nonlinear Optical Properties of the Chiral Camphorderived β-diketonate Platinum Complexes

UV-Vis spectrum and the third-order nonlinear optical properties of the chiral camphor-derived β-diketonate have been studied at the B3LYP/6-31G＊ level. The results showed that the introduction of electron-drawing group -CF3 and -C3F7 on β-diketonate made the strongest absorption peak red-shift and the lowest energy absorption blue-shied. Introduction of -OC2H5 on the benzene or pyridine ring made the lowest energy absorption blue-shift. When the -C2H3 was introduced on the benzene or pyridine ring, the lowest energy absorption was red-shifted. Introduction of electron-donating group on β-diketonate can enlarge their nonlinear optical properties. On the contrary, the introduction of electron-drawing group dropped it down.

Study on the ultraviolet-visible spectral feature of tobacco leaves by pattern recognition

In order to differentiate regions, varieties, and parts of tobacco leaves, two pattern recognition methods through pattern classification modeling were developed based on the comprehensive information of ultraviolet-visible spectroscopy （UV-VIS） by employing one-way analysis of variance （ANOVA1） and wave range random combination （WRRC） technology from MATLAB. This proposed classification method has never been reported previously and the instrument and operation for this method is much more convenient and efficient than previous reported classification methods. The result of this paper demonstrated that the spectral features extracted by ANOVAI and WRRC methods could be used to differentiate tobacco leaves with different patterns. The ANOVAI method had a training recognition rate range of 75.00-87.50%,4 and a validation recognition rate range of 57.14-100%. The WRRC method had a training recognition rate range of 75.00-94.12% and a validation recognition rate range of 66.67-100%. The ANOVAI method is more convenient and efficient in model developing, while the WRRC method utilizes fewer model variables and is more robust.

Three New Coordination Polymers Constructed by Adjusting the Angles of Pyridyl or Imidazolyl-based Synthons： Structures and Solid UV-vis Properties

Three new 2D metal-organic frameworks, [M（BIDPE）2（bdc）2]n（M = Co for 1, Ni for 2） and [Ni（PIDPE）2（H2O）2（bdc）]n（3）（BIDPE = 4,4A-bis（imidazol-1-yl） diphenyl ether, PIDPE =4-（pyridyl）-4A-（imidazol-1-yl） diphenyl ether, bdc2- = 1,3-benzenedicarboxylate）, were characterized by single-crystal X-ray diffraction, elemental analysis, PXRD, IR spectroscopy and TGA analysis.Complex 1 crystallizes in monoclinic, space group P21/n, with a = 9.1568（12）, b = 16.943（2）, c =15.441（2） A, β = 104.049（2）°, V = 2323.9（5） A^3, Dc = 1.420 g/cm^3, Mr = 993.83, F（000） = 1026, μ =0.440 mm-（-1） and Z = 2. Complex 2 crystallizes in monoclinic, space group P21/n, with a =9.1395（17）, b = 17.019（3）, c = 15.473（3） A, β = 104.651（2）°, V = 2328.5（7） A^3, Dc = 1.414 g/cm^3,Mr = 991.58, F（000） = 1024, μ = 0.487 mm^-1, Z = 2. Complex 3 also belongs to the monoclinic system, space group P21/n, with a = 11.4365（16）, b = 18.346（3）, c = 11.7068（17） A, β = 91.022（2）°,V = 2455.9（6） A3, Dc = 1.422 g/cm^3, Mr = 1051.66, F（000） = 1092, μ = 0.468 mm^-1, Z = 2. All complexes 1, 2 and 3 are 2D layer structures constructed from intermolecular hydrogen bonds. In addition, the solid UV-vis properties of complexes 1, 2 and 3 were also studied.

Crystal Structure and Spectrum Character of Bis[1-(4-Methoxyphenyl)-3-(1H-1,2,4-Triazol-1-yl)-1-Propanone] dichorozinc(Ⅱ) Complex

The titled new complex was synthesized and determined by X-ray diffraction. The crystal belongs to monoclinic, P-I group, a=1.8997（4）nm, b-0.581 07（12）nm, c=2.4209（5）nm, β-90.65（3）°, V=2.672 2（9） nm^3, Z=4, Dc= 1.488 g/cm^3, It has C2 symmetry with the axis through the Zn atom, and the zinc atom is coordinated by two N atoms of the 1-（4-methoxyphenyl） 3-（ 1H-1, 2, 4-triazol-1-yl）-1-propanone ligands and two C1^- atoms, forming a slightly distorted tetrahedron. Intermolecular hydrogen bonds make the complex stable. IR and electronic spectra study of the target complex were also carried.

溶胶-凝胶法制备Al^3＋掺杂ZnO薄膜的结构和光学性能

采用无机盐溶胶-凝胶方法在载玻片衬底上制备了ZnO:Al薄膜,利用X射线衍射(XRD)、紫外-可见光透射光谱(UV-Vis transmittance spectrum)和扫描电镜(SEM)研究了退火温度和Al3+掺杂浓度对ZnO:Al薄膜结构和光学性能的影响。结果表明,随退火温度的升高或进行适当浓度的Al3+掺杂,可使(002)衍射峰的强度增强,晶粒尺寸增大,半高宽减小,薄膜的结晶质量明显改善,且可见光透过率高。

Synthesis and photochemical properties of two ICT compounds with naphthalimide and diarylamine units

Two new diarylamine-substituted 1, 8-naphthalimide derivatives are synthesized by Cu I/18-crown-6/K2CO3 catalyst system and characterized by Fourier transform infrared （FT- IR）, ^1H-NMR and elemental analyses. The UV-vis absorption and photoluminescent （PL）spectra of the systems in n-hexane, tetrahydrofuran（THF）, and CH2Cl2 are investigated. These naphthalimide molecules have an absorption band centered at about 450 nm, which is assigned to an intramolecular chargetransfer （ICT）transition, and they emit light at 492, 501 nm in a nonpolar solvent such as n-hexane, and at 600, 620 nm in a polar solvent such as CH2Cl2. From the Lippert-Mataga equation, the difference of the dipole moment between the excited state and the ground state is estimated to be 9.2 and 9.8 D for 4- （ diphenylamine ）-N-（ 2-methoxyphenyl ）-1, 8-naphthalimide （ DMN-1 ） and 4-（ 2-naphthylphenylamine ）-N-（ 2- methoxyphenyl）-1, 8-naphthalimide （DMN-2）, respectively. This large change in the dipole moment upon excitation is typical for photoinduced ICT processes.

Online recognition of drainage type based on UV-vis spectra and derivative neural network algorithm

Optimizing sewage collection is important for water pollution control and wastewater treatment plants quality and efficiency improvement.Currently,the urban drainage pipeline network is upgrading to improve its classification and collection ability.However,there is a lack of efficient online monitoring and identification technology.UV-visible absorption spectrum probe is considered as a potential monitoring method due to its small size,reagent-free and fast detection.Because the performance parameters of probe like optic resolution,dynamic interval and signal-to-noise ratio are weak and high turbidity of sewage raises the noise level,it is necessary to extract shape features from the turbidity disturbed drainage spectrum for classification purposes.In this study,drainage network samples were online collected and tested,and four types were labeled according to sample sites and environment situation.Derivative spectrum were adopted to amplify the shape features,while convolutional neural network algorithm was established to conduct nonlinear spectrum classification.Influence of input and network structure on classification accuracy was compared.Original spectrum,first-order derivative spectrum and a combination of both were set to be three different inputs.Artificial neural network with or without convolutional layer were set be two different network structures.The results revealed a convolutional neural network combined with inputs of first and zero-order derivatives was proposed to have the best classification effect on domestic sewage,mixed rainwater,rainwater and industrial sewage.The recognition rate of industrial wastewater was 100%,and the recognition rate of domestic sewage and rainwater mixing system were over 90%.

Monitoring the hydrolyzation of aspirin during the dissolution testing for aspirin delayed-release tablets with a fiber-optic dissolution system

The purpose of this study was to investigate the hydrolyzation of aspirin during the process of dissolution testing for aspirin delayed-release tablets. Hydrolysis product of salicylic acid can result in adverse effects and affect the determination of dissolution rate assaying. In this study, the technique of differential spectra was employed, which made it possible to monitor the dissolution testing in situ. The results showed that the hydrolyzation of aspirin made the percentage of salicylic acid exceed the limit of free salicylic acid （4.0）, and the hydrolyzation may affect the quality detection of aspirin delayed-release tablets.

Electronic Structure and Physical Characteristics of Dioxin Under External Electric Field

Dioxin is a highly toxic and caustic substance,which widely existed in the atmosphere,soil and water with tiny particles.Dioxin pollution has become a major problem that concerns the survival of mankind,which must be strictly controlled.The bond length,bond angle,energy,dipole moment,orbital energy level distribution of dioxin under the external field are investigated using DFT(density functional theory)on basis set level of B3LYP/6-31G(d,p).The results indicate that with the increase of the electric field,the length of one Carbon-Oxygen bond increases while another Carbon-Oxygen bond decreases.The energy gradually decreases with the electric field,while the change of the dipole moment has an opposite trend.In the infrared spectra,the vibration frequency decreases with the electric field increasing and shows an obvious red shift.Moreover,the ultraviolet-visible absorption spectra under different electric fields are analyzed with TD-DFT(time-dependent density functional theory)method.The wavelength of the strongest absorption peak increases and occurs red shift with the increase of the electric field.All the above results can provide reference for further research on the properties of dioxin under different external electric field.

Spectroscopic Studies on Co(Ⅱ),Ni(Ⅱ),Zn(Ⅱ) Complexes with 4,4'-Bipyridine

Fourier-transform infrared（FTIR）,Raman and ultraviolet-visible spectra of 4,4＇-bipyridine and its me-tal-organic coordination compounds synthesized from 4,4＇-bipyridine and nitrate of Co（Ⅱ）,Ni（Ⅱ） and Zn（Ⅱ） were measured and analyzed,respectively.The main FTIR and Raman bands were assigned in detail.The relationship between these characteristic bands and the structure of ligands and coordination compounds were discussed.

Spectra of Linear Polyene Molecule-canthaxanthin

Raman spectra and ultraviolet-visible（UV-Vis） absorption spectra of linear polyene molecule-canthaxan-thin in n-hexane are measured and analyzed.In addition,the optimized structure of canthaxanthin was calculated via density functional theory（DFT） functional B3LYP.With decreasing the concentration,Raman scattering cross section （RSCS） of fundamental frequency is extremely high,and the UV-Vis absorption bands become narrower.The results of coherent weakly damped electron-Lattice vibration model were analyzed.

Construction of J- and H- Aggregates of meso-Tetrakis (4-hydroxyphenyl) porphyrin Diacid (H_4THPP^(2+))

UV-Vis spectrum was utilized to study the aggregation behaviors of H4THPP2+ inDMF-chloroform mixture and water. It was found that J-aggregation of H4THPP2+ was formed inDMF-chloroform mixture and H-aggregate was formed in aqueous solution with highionic-strength, as indicated by different spectral characteristics of different H4THPP2+ aggregates.

Density Functional Theory Study of Infrared and Ultraviolet Spectra of Urea L-Malic Acid

Urea L-malic acid, a new second order nonlinear optical crystal, was studied using density functional theory （DFT）. PBEPBE/6-31＋G（d,p） method, the optimal method for comparing the results from the several DFT methods, was chosen to study the molecular structure. Infrared and ultraviolet-visible spectra were obtained and compared with experiments. The ultraviolet-visible spectrum was also analyzed by the molecular orbital population. The geometries, and the infrared and ultraviolet-visible spectra in water were studied using DFT methods in combination with the polarized continuum model to predict the perturbations by the solvent effect.

Synthesis and Spectral Characteristics for Zinc Tetraphenylporphyrin Modified Zinc Oxide Nanowires

A nest-like architectures(ZnO NAs)were prepared onto the conductive glass(ITO)by hydrothermal method.A metal-free porphyrin,tetraphenylporphyrin(H2TPP),was synthesized via Adler method.Zn ions with Zn-unsaturated coordination bonds on the surface of ZnO NAs were used as a template,and also H2TPP was used as"molecular fragments".Zinc tetraphenylporphyrin(ZnTPP)molecules were obtained on the surface of ZnO NAs by in-situ method.ZnO NAs direct provides of zinc source makes ZnTPP stably coated on the surface of ZnO NAs nanosheet,formed a tight composite materials(ZnTPP/ZnO NAs).Due toZnTPP with four phenyls in meso position,the surface of ZnTPP/ZnO NAs was with hydrophobic property.In the photocatalytic experiment,the degradation selectivity for phenol(hydrophobicity)in the mixture of phenol and rhodamine B(hydrophily)was increased under visible irradiation.

Synthesis and Spectroscopic Properties of a Series of New tetra-Substituted Metal Phthalocyanines

A new class of metal phthalocyanines（MPcs） containing four 8-quinolinol（8-QH） derivative moieties were successfully synthesized and characterized by mass spectroscopy, IR, UV-Vis and element analysis, the results of which were consistent with the proposed structures. All of them can dissolve in common organic solvents, such as dichloromethane, chloroform, and acetone. The effect of metal ion on the absorption of Q band was studied with UV-Vis spectra. The fluorescent properties for those complexes were also investigated.

Synthesis,Crystal Structure and Photoluminescence of Ethyl Coumarin-3-carboxylate Derivatives

The ethyl coumarin-3-carboxylate （1） and its two derivatives, ethyl 7-methoxy-2- oxo-2H-chromene-3-carboxylate （2） and ethyl 7-（3-methylbut-2-enyloxy）-2-oxo-2H-chromene-3- carboxylate（3）, were synthesized, characterized and their UV-vis spectra and photoluminescence were investigated. Compound 2 crystallizes in the monoclinic system with space group C2/c, a = 25.884（4）, b = 6.8365（11）, c = 13.816（2） A, β = 104.876（2）°, V= 2362.9（7） A3, Z = 8, Dc= 1.396 g/cm3, Mr. = 248.23, F（000） = 1040 and g = 0.108 mm-1. Compound 3 crystallizes in the monoclinic system with space group P21/c, a = 15.685（6）, b = 8.373（3）, c = i3.063（5） A, β = 111.862（6）°, V= 1592.2（10） A3, Z = 4, Dc = 1.261 g/cm3, M,.= 302.31, F（000） = 640 and p = 0.093 mm^-1. Both the absorption and emission of the two derivatives were stronger than that of ethyl coumarin-3-carboxylate due to the larger conjugation of their electron donor group moiety at the 7-position. Under ultraviolet light excitation, the two derivatives exhibit strong blue-violet emission.

Different J-Type Aggregates of meso-Tetrakis (4-hydroxyphenyl) porphyrin (H_(2)THPP) Formed in Different Solvents

The aggregation of meso-tetrakis(4-hydroxyphenyl)porphyrin (H2THPP) in dimethyl- formamide (DMF)-water solution and in DMF-chloroform solution was studied by UV-vis absorption spectroscopy. The red shift of Soret band indicates the formation of J-type aggregates of H2THPP in these two solutions. However, different shift extent of Soret band, 12 nm in DMF-water solution and 32 nm in DMF-chloroform solution, implies structural difference between these two J-type aggregates. The hydrogen bond between hydroxyl group and N-H bonds in porphyrin ring is thought as the main cause to the formation of J-type aggregate in DMF- chloroform solution, whereas the π?σ interaction between two adjacent porphyrin cores is thought as the main cause of the formation of J-type aggregate in DMF-water solution

Size-controlled flow synthesis of metal-organic frameworks crystals monitored by in-situ ultraviolet-visible absorption spectroscopy

Size-controlled flow synthesis of nanoporous particles are of considerable interest for future industrial applications,however,is facing challenges due to lack of in-situ method for size-characterization in fluidic environment.We present that ultraviolet-visible(UV-vis)absorption spectroscopy can be integrated into a flow-synthesis system which was produced by femtosecond laser micro machining.The shift of the absorption peak position of the ex-situ and in-situ UV-vis spectra correlates to variation of size of porous metal-organic frameworks crystals.ZIF-67 crystals with a size in the range from 200 nm to1025 nm are fabricated with the assistance of tri-ethylamine under monitoring of in-situ UV-vis spectra.The ZIF-67 crystals are converted into nanoporous carbons particles with controlled sizes.These materials show size-dependent performance in Na-ion battery and size-independent performance in metal/H_(2)O seawater battery.

Construction of a 3D Co(Ⅱ) Framework Based on Two Types of V-shaped Bidentate Ligands

A three-dimensional （3D） coordination polymer {[Co（bdc）（dpb）]·H2O}n （1） was prepared by solvothermal reaction of 1,3-dipyridyl benzene （dpb） with deprotonated 1,3-benzene- dicarboxylate （H2bdc）, and was characterized by elemental analysis, IR spectroscopy, and X-ray single-crystal diffraction. It crystallizes in the monoclinic system, space group C2/c with α = 15.478（6）, b = 12.865（5）, c = 24.091（10） ？, β = 95.599（5）°, V = 4774（3） ？3, C24H18CoN2O5, Mr = 473.34, Dc = 1.267 g/cm3, F（000） = 1864.0, μ = 0.748 mm-1 and Z = 8. Each Co（II） ion links three bdc2- anions to form an infinitely 1D ladder-shaped chain containing binuclear [（COO）Co]2 cluster, and dpb links adjacent 1D chains to form a 3D pcu framework. In addition, the UV-vis of 1 was also studied.