Study of Vibronic Spectra of Tetrabenzoporphin Based on Normal-Coordinate Analysis

The quasi-line fluorescence spectra have been measured and analyzed in detail for the molecules of tetrabenzoporphin and its N-deuterated derivative in n-octane. The calculations of the normal modes of these molecules have been carried out with the use of the valence force fields of porphin and phenanthrene. Sufficiently good agreement of the calculated and experimental frequencies of the modes has been obtained without variation of the force constants. Detailed interpretation of the fluorescence spectra is given.     

Vibrational structure of quasiline fluorescence and absorption spectra of bisanthene molecules

The quasiline spectra of the fluorescence and absorption of bisanthene in n-hexane are obtained at 77 and 4.2 K, and their vibration analysis is carried out. Substantial violation of the mirror symmetry of the fluorescence and S₁ ← S₀-absorption bands with respect to both the frequencies and intensities is found. This allowed the conclusion that the S₂-level is localized in the region of vibronic sublevels of the S₁-state with . Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 4, pp. 488–491, July–August, 2000.     

双原子分子电子光谱的振动结构分析

从电子振转能级的光谱项出发,分析了双原子分子电子振动谱带序和电子振动谱带列的规律,并归纳出德兰德斯表(Deslandres table)及其主要性质。以C₂分子电子振动光谱的斯簧谱带系作为实例,说明了如何对电子振动光谱的测量值进行标识,并将它们按振动结构规律整理成德兰德斯表,从而获得有关分子光谱不同态的非谐性常数、振动频率等重要参数以及任意谱带的波数公式。     

Effect of the Pyranose Ring Conformation on the Vibrational Spectra of Sugar Epoxides

Normal vibrations of two sugar epoxides — methyl 2,3-anhydro-4-deoxy--D-ribohexopyranoside and methyl 3,4-anhydro--D-talohexopyranoside — have been carried out by the molecular mechanics method. Parametrization of the force field used has been performed and the parameters of the oxirane ring for sugar epoxides have been determined. A good agreement between the experimentally observed and calculated frequencies has been obtained. The IR spectral absorption bands of the molecules under investigation in the 1500–400-cm^–1 range have been assigned on the basis of the potential energy distribution function of normal vibrations. The investigation of the potential energy surface of these molecules has shown that their pyranose ring can take conformations close to half-chair, boat, skew boat, and twist forms. Comparative analysis of the normal vibrations of various conformers has revealed that the form of the pyranose ring influences the vibrational spectra of sugar epoxides.     

Physicochemical Studies on Solid Products of Reactions of Chromyl Chloride and Chromyl Acetate with Alkylaromatics. Part II. Electronic Absorption Spectra

The electronic absorption spectra of some chromium(IV) complexes as the products of chromyl chloride and chromyl acetate reaction with alkylaromatics have been studied in some organic solvents. A detailed computer analysis of the spectra including resolution into component bands as well as calculation of crystal field parameter Dq, Racah's parameter B and Franck-Condon analysis of the vibronically structured charge-transfer O—Cr band have been performed. The solvent effect on the Dq parameter has been established.     

Vibrational Spectra and Normal Coordinate Analysis for an Imidazole Bridged Copper,Zinc Binuclear Complex

Abstract

The normal coordinate analysis of a model compound for Cu, Zn-SOD: [(dtma)CuImZn(dtma)]CIO₄ · 2.5H₂O (where dtma = 4-diethylenetriamineacctate; Im = imidazolate) has been carried out by using a Urey-Bradley force field. According to the molecular structure, 240 internal coordinates were established and 174 theoretical vibrational frequencies were calculated. Due to introducing an appropriate set of internal coordinates and force constants in the course of calculation, the calculated frequencies agree well with the observed values, with the average difference 4.40cm^?1 and the maximum deviation 24.2cm^?1 between them, although the structure of the title compound is complicated. Some structural and spectral properties are here discussed.     

微分谱结合独立成分分析对三维荧光重叠光谱的解析

多组分三维荧光重叠光谱是三维荧光光谱的数据解析中的难点之一。本文基于二维微分谱的计算原理, 充分利用三维荧光光谱具有激发光谱和发射光谱的特点, 获得了三维荧光光谱展开后的激发微分谱和发射微分谱. 之后利用独立成分分析对激发光谱或发射光谱的多组分混合微分谱分别进行解析, 得到了单一组分的激发微分谱和发射微分谱。其中三次样条插值有效的弥补了实测激发波长数据点少的缺点, 而粗糙惩罚平滑技术的引入则很大程度上减少了发射光谱的噪声,为微分谱的计算提供了有利的条件。单一组分的标准谱与解析谱的相似性系数的计算表明, 利用独立成分分析对微分谱进行解析更有利于多组分混合三维荧光光谱所含成分的识别。     

Computer Resolution and Franck-Condon Analysis of the Electronic Absorption Spectrum of KMnO4 in Water

Abstract

The electronic absorptíon spectrum of KMnO₄ in water solution was analyzed. The spectral contour was resolved into component bands and then Franck-Condon approach was applied. In the investigated range of 13000–48000 cm^?1 a presence of three structureless and of two vibronic strong bands was stated. The change in the Mn-O equilibrium bond length was found to be 10.5pm for 2e·1t₁ transition (vibronic band about 18000cm^?1) and to be 16pm for the 2e·3t₂ transition (vibronic band about. 30000cm_?1). The appropriate wavenumber of the vibrational mode in these excited electronic states was found to be 735cm^?1 and about 780cm^?1, respectively. The ground electronic state wavenumber of the totally symmetric vibrational mode was fitted to be equal to 828cm^?1. Details of the proposed method of computer elaboration of electronic spectra with vibrational structure were discussed.

Electronic absorption spectra of some inorganic comppunds consist of a number of strongly overlapped bands due to their vibronic structure.^1–5 A detailed analysis of spectral contours of such compounds provides some useful information about their structure in both ground excited electronic states.

The electronic spectrum of permanganate ion is the typical example of vibronic spectra.¹ The main part of the past works based on the analysis of permanganate ion spectra in low temperatures and different polarizations. In such conditions the vibronic structure is rather good resolved and can be effectively studies.^1,3,6 Spectra of solutions as a rule are relatively poor resolved so their analysis has to be more sophisticated.

The main purpose of this work is a presentation of a new computer method for an effective study of vibronic spectra of solutions. This method has been applied to the electronic absorption spectrum of KMnO₄ in water. The method allowed us to fit the geometric parameters of spectral contour, to establish the origins and parameters of two progressions in the UV/VIS range as well as to calculate the changes in the Mn-0 equilibrium bond lengths and vibrational energy resulting from the electronic excitations of the soluted permanganate ion.     

煎炸食用油质量变化的同步荧光光谱研究

利用同步扫描荧光光谱法,并结合红外吸收光谱法对经过高温煎炸的几种食用油进行了分析和研究.实验发现,与新油相比煎炸后的食用油在370~380 nm附近的荧光峰消失,表明一些营养物质（如维生素E）的挥发或分解;而461 nm和479 nm附近出现的新荧光峰,和红外光谱区1745 cm附近的红外吸收增加表明油样中含有羰基C＝O基团的物质的增加.从而表明荧光光谱方法可以用来对煎炸食用油进行检测.     

Structure of the Absorption and Fluorescence Spectra of Solutions of Silico-Organic Polymers

The spectroscopic characteristics of new -linked polymers, whose main chain contains tetracoordinated silicon, acetylene groups, and 1,4-biphenyl or 2,7-fluorene, in chloroform have been investigated. It has been established that the spectral features of the absorption, fluorescence, fluorescence excitation, and fluorescence polarization spectra of these polymers are due to the inhomogeneous broadening of the electronic states of the centers of two types formed in the disordered polymer chain.     

The Synthesis,Vibrational Spectra,Electronic Spectra,and Thermal Analysis of Some Mixed Complexes with Planar Dithiooxamides

Planar Pd(LH)₂ complexes (LH₂ = H₂N C S C S N H₂, CH₃HNCSCSNHCH₃) form mixed polymeric complexes with Ni(II), Cu(II), Zn(II) and Cd(II) in alcalic media, where the planar Pd(LH)₂ complexes act as tetradentates with N-coordination. The electronic spectra and thermal behaviour are discussed, a thorough investigation of the i.r. spectra is presented and special attention has been given to the H/D, CH₃/CD₃ and ⁵⁸Ni/⁶²Ni, ⁶³Cu/⁶⁵Cu and ⁶⁴Zn/⁶⁸Zn isotopic shifts.     

大气湍流波前低阶模式的时间功率谱分析

引入规格化的相位谱,推导了大气湍流波前低阶模式（Ｚ－倾斜和Ｇ－倾斜、离焦、像散以及彗差）的时间功率谱,并就水平大气传输、星体目标观测、空间目标监测等几种情况作了实际的数值计算及分析,此外还给出实验结果,分析结果表明：对于水平大气传输模式,倾斜功率谱曲线的低频阶段的指数下降因子为４／３－６β／１１（β为相位谱空间频率的指数下降因子）,离焦、像散和彗差项的功率谱低频段指数下降因子为０;水平大气传输工作     

Spectral-luminescent properties and photoinduced transformations of bisanthene and bisanthenequinone

Based on the study of photochemical transformations of bisanthene in oxygen-containing solutions, it was established that the final product of this reaction is bisanthenequinone. It is shown that in the course of this oxidation reaction the intermediate compounds endomonoperoxide and bisanthene endobiperoxide are formed. Quantum-chemical calculation of the geometrical structure and electronic spectra of the endoperoxides has shown that they have a nonplanar structure, and their absorption spectra experience a large hypsochromic shift. The absorption and fluorescence spectra of solutions of bisanthene in different solvents at 300 and 77 K were investigated. The large Stokes shift of the fluorescence spectra of the solutions of bisanthene in benzene and in its methyl derivatives is explained by the action of intermolecular interactions. The quasi-line fluorescence spectra of solutions of bisanthene in the matrices of saturated hydrocarbons were recorded. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 2, pp. 176–182, March–April, 2000.     

乙酰苯胺分子的拉曼、红外光谱和简正振动分析

分别在3 500～50和3 500～600 cm-1范围内实验测量了乙酰苯胺(ACN)分子的拉曼和红外光谱。运用密度泛函理论(DFT)采用B3LYP 混合泛函和6-311G(d, p)基函数组,计算了该分子的平衡构型和振动频率。结果表明：理论计算的分子最优化构型参数与以往文献报道的实验数据吻合,优于以往由6-31G(d)基函数组计算得到的参数;理论计算的振动频率值和本实验的观测值吻合得较好。运用简正振动分析方法得到了ACN 分子各振动频率的势能分布(PED),对ACN 分子的振动频率归属做出了全面、准确指认。     

Excitation of Forbidden Electronic Transitions in Atoms by Hermite–Gaussian Modes

Photoexcitation of trapped ions by Hermite–Gaussian (HG) modes from guided beam structures is proposed and investigated theoretically. In particular, simple analytical expressions for the matrix elements of induced atomic transitions are derived that depend both on the parameters of HG beams and on the geometry of an experiment. By using these general expressions, the ${}^2{S}_{1/2}\to {}^2{F}_{7/2}$ electric octupole (E3) transition is investigated in an Yb⁺ ion, localized in the low–intensity center of the HG₁₀ and HG₀₁ beams. It is shown how the corresponding Rabi frequency can be enhanced by properly choosing the polarization of incident light and the orientation of an external magnetic field, which defines the quantization axis of a target ion. The calculations, performed for experimentally feasible beam parameters, indicate that the achieved Rabi frequencies can be comparable or even higher than those observed for the conventional Laguerre–Gaussian (LG) modes. Since HG-like modes can be relatively straightforwardly generated with high purity and stability from integrated photonics, these results suggest that they may form a novel tool for investigating highly-forbidden atomic transitions.     

Vibrational Spectra of Arsenates and Phosphates of the Type Kcaln(XO4)2

The infrared and Raman spectra of polycrystal-line samples of different compounds of the types KCaLn(AsO₄)₂ and KCaLn(PO₄)₂, belonging to the hexagonal LaPO₄, structural modification, were recorded and discussed. A complete vibrational assignment, based on a factor group analysis, is proposed. The influence of the different lanthanide cations on the internal vibrations of the XO₄ groups is briefly discussed and some comparisons with related compounds are also made.

It is well known that simple lanthanide arsenates, phosphates, vanadates and cnromates (V) of the type LnXO₄ belong to two different structural types.     

亚已基硫脲分子的拉曼、红外光谱和简正振动分析

实验测量了亚乙基硫脲分子的拉曼和红外光谱, 用量子化学方法计算了分子的几何构型以及振动频率, 以实验频率为标准对分子内力场进行了标度, 采用简正振动分析方法得到了各振动频率的势能分布, 从而对亚乙基硫脲分子的振动频率归属做出了全面指认。     

二甲基硅硼烷,o-(SiMe)_2B_(10)H_(10),振动光谱的理论研究

本文利用高斯 94从头计算程序在 6- 31 G基组下对二甲基硅硼烷 ,o- (Si Me) 2 B1 0 H1 0 ,进行几何优化及振动光谱的理论计算 ,并对主要谱带特性进行指认 ,结果与实验基本符合。振动模式分析表明 450 cm-1 以下的两个强带中 32 6cm-1 (计算值为 369cm-1 )似乎是两个 Si原子相对笼骨架中其余 B原子整体的伸缩振动 ,而 399cm-1 (计算值为 42 1 cm-1 )则为 Si- Si(及其联带的 C原子一起参与的 )对称伸缩振动。优化几何及振动光谱的研究表明重的杂原子硅占据二十面体硼笼骨架位置后使笼结构的刚性弱化     

血清白蛋白与小分子化合物相互作用的荧光光谱研究

以牛血清白蛋白-Triton X-100和牛血清白蛋白-盐酸西布曲明两个体系为实例,考察了以血清白蛋白和小分子化合物为荧光检测对象所获得的相互作用信息的差异。发现两种方法获得的分子间结合常数差异显著,说明在以血清白蛋白为检测对象的传统荧光光谱法中,以色氨酸基团的荧光光谱所表达的信息来代表整个蛋白分子的相互作用信息是不准确的。文章提出了以荧光小分子化合物为检测对象的改进荧光光谱方法和荧光背景扣除方法,前者能全面表达相互作用过程中分子的整体信息,后者实现了荧光光谱交叠体系的荧光光谱法相互作用分析。     

槲皮素-Sn(II)配合物荧光、紫外及红外光谱的测量与分析

以NH4Cl-NH3.H2O为缓冲液,十六烷基三甲基溴化铵(CTAB)为荧光增强剂,用荧光分光光度计分别采集槲皮素、槲皮素-Sn(II)配合物溶液、槲皮素-Sn(II)-NH4Cl-NH3.H2O、槲皮素-Sn(II)-NH4Cl-NH3.H2O-CTAB溶液以及将其溶液分别静置7h和21h后的荧光光谱,并对光谱进行分析。在不加CTAB的条件下,用紫外分光光度计分别测量加入缓冲液前后的紫外光谱。用漫反射方法测定配合物的红外光谱,并对其结构进行初步分析。在缓冲液的作用下,槲皮素-Sn(II)配合物的结构发生了变化;通过分析,发现与缓冲液发生反应的主要基团为酚羟基,红外光谱中酚羟基的消失和NH4+基团的出现,说明了配合物中的酚羟基与NH4+发生了取代反应。