Spectroscopic investigation of the donor-acceptor interaction between o-phenylenediamine and tetracyanoethylene in dichloromethane

The interaction between the electron donor o-phenylenediamine (o-phendn) and the pi-acceptor tetracyanoethylene (TCNE) has been investigated spectrophotometrically in dichloromethane at 25 degrees C. The results indicate that the reaction proceeds via two major steps. The formation of the 1:2 charge-transfer complex [(o-phendn)(2), (TCNE)(4)] in which two o-phenylenediamine molecules undergoes slow N-substitution by one TCNE forming the final reaction product 2,2-di-o-aminoaniline-1,1-dicyanoethylene and 2HCN molecules. The reaction was studied using electronic, infrared, photometric titration and cyclic voltametric measurements. A general mechanism for the reactions is proposed.     

Molecular dynamics modeling in quantum chemical calculations. Optical absorption spectra of 1,3-Dimethyl-1H-Pyrazolo[3,4-b]quinoline derivatives

Paper presents the quantum chemical modeling of the optical absorption spectra of 6-fluoro, 6-bromo, 7-trifluoromethyl, 6-cyano and 6-carboethoxy derivatives of 1,3-Dimethyl-1H-Pyrazolo[3,4-b]quinoline. The calculations are performed by means of the semiempirical quantum chemical methods (AM1 or PM3) in combination with molecular dynamics (MD) simulations at T=300 K. It is shown that a particular rotational dynamics of the methyl, trifluoromethyl or ethyl groups practically does not influence the optical absorption in the spectral range 200-500 nm whereas broadening of absorption bands may be well reproduced within MD simulations including all types of nuclei vibrations. The results of calculations are compared with the measured spectra of optical absorption. The quantum chemical method AM1 in combination with MD simulations gives for all dyes the best agreement between the calculated and measured spectral positions of the first absorption band (absorption threshold).     

Mononuclear and binuclear sandwich copper(II) complexes with poly(pyrazolyl)borate ligands: syntheses, structures and properties

A series of Cu(II) complexes Cu(2)[micro-pz](2)[HB(pz)(3)](2) (1), Cu[H(2)B(pz)(2)](2) (2), Cu[HB(pz)(3)](2) (3), Cu[HB(pz(Me2))(3)](2) (4), Cu[B(pz)(4)](2) (5) (pz=pyrazole), have been synthesized and characterized by elemental analysis, IR, UV-vis, X-ray diffraction, thermal analysis and theoretical analysis. The IR spectra give the Cu-N vibration modes at 322, 366, 344, 387, and 380 cm(-1) in complexes 1-5, respectively. The UV spectra show all the complexes have same UV absorption at 232 nm; there is another band at 332 nm for complexes 1, 2 and 4, while for complexes 3 and 5, the bands are at 272 and 308 nm, respectively. Complex 1 has a binuclear structure in which two pyrazole ligands bridge two Cu-Tp units. In 2-5, the Cu(II) centers are coordinated with dihydrobis(pyrazolyl)borate (Bp), hydrotris(pyrazolyl)borate (Tp), hydrotris(3,5-Me2pyrazolyl)borate (Tp'), tetrakis(pyrazolyl)borate (Tkp) respectively to form a mononuclear structure. The results of thermal analysis for complexes 1-5 are discussed too.     

含酰胺基团稀土配合物的红外光谱

本文合成了未见文献报道的氯化稀土丙酰胺配合物,剖析了ＬｎＣｌ３．３ＰＡ和聚（苯乙烯－丙烯酰胺）负载氯化稀土配合物（ＳＡＡ．ＬｎＣｌ３）的红外光谱和电子能谱,结果表明,含酰胺基团的配体均通过羰基氧与稀土离子配位。     

镧系四元混配化合物[Ln(BA)2(NO3)(phen)]2的合成、晶体结构和波谱研究

在酸性介质、含水溶剂中合成了四元混配化合物[Ln(BA)₂(NO₃)(phen)]₂(BA=苯甲酸根;Ln=La,Ce,Pr,Nd,Sm,Eu,Dy,Gd,Tb,Er),用元素分析、IR、DTA-TG等方法对配合物进行了表征.研究了配合物的顺磁性能和荧光性能.镨配合物的单晶衍射结果表明,配合物属三斜晶系,双核,Pr³⁺的配位数为9,4个BA呈二种配位方式,丰富了四元配合物的结构表现形式.     

波长40—60nm的高电离态硫离子某些能级跃迁谱线的实验研究

波长４０－６０ｎｍ的元素高电离态离子光谱实验中,观测到１０多条光谱线,这些谱线是ＳＸＩ到ＳＸⅣ离子的一些激发能级发射的,其中９条谱线还没有人报道实验结果,实验分析结果与理论符合得较好。     

An electronic spectroscope for classroom displays of visible spectra

This article is an electronic publication in Spectrochimica Acta Electronica (SAE), a section of Spectrochimica Acta Part B (SAB). The hardcopy text is accompanied by an electronic archive, stored on the SAE homepage at http://www.elsevier.nl/locate/sabe. The archive contains program, data and text files. The hardcopy text describes a program that has been developed to accept data from a compact electronic spectrograph and translate the data into a display on a computer screen. The computer display mimics the view seen through a direct vision spectroscope. Atomic spectra appear as vertical lines of the appropriate color dispersed on a black field. A conventional plot of intensity versus wavelength is simultaneously displayed. The update of the display is sufficiently rapid that the image on the screen is essentially a real-time representation of the light entering the spectrograph. The system was designed for use in conjunction with video projection equipment in demonstrations to large groups of students.     

Hg2+处理对经NBS修饰前后BSA光谱性质的影响

pH7.0时Hg^2 处理导致BSA紫外吸收增加,出现LMCT带,强度随处理时间增加而增强,蛋白质内源荧光强度下降。而Hg^2 处理对经NBS修饰的BSA的紫外吸收LMCT带强度随处理时间增加而降低,278nm波长光激发所得最大荧光发射峰位置出现蓝移,也与处理时间相关。表明重金属Hg^2 对BSA除Trp残基附近外还有多个作用部位。     

Zweikernige Antimon(V)-Komplexe mit Diphenylphosphato-Brückenliganden

Binuclear Antimony(V) Complexes with Bridging Diphenylphosphato Ligands The binuclear antimony(V) complexes Cl₃Sb(O)[(C₆H₅O)₂PO₂]₂SbCl₃ ( 1 ), Cl₃Sb(O)[(C₆H₅O)₂PO₂](OCH₃)SbCl₃ ( 2 ), Cl₃Sb(O)[(C₆H₅O)₂PO₂](OH)SbCl₃ ( 3 ) and Cl₄Sb[(C₆H₅O)₂PO₂]₂SbCl₄ ( 4 ) are prepared by reaction of diphenylphosphoric acid with antimony(V) chloride, water and methanol in different molar ratios. The progress of the reactions was controlled by the ³¹P-NMR signals. 1 crystallizes triclinic in the space group P1 with a = 918.8, b = 1312.9, c = 1395.8 pm, α = 91.91, β = 101.36, γ = 95.90° and Z = 2. 2 to 4 crystallize in monoclinic space groups: 2 : C2/c, a = 2753.4, b = 1156.1, c = 1476.7 pm, β = 98.01° and Z = 8; 3 : P2₁/c, a = 1234.8, b = 1471.8, c = 1263.4 pm, β = 107.15° and Z = 4; 4 : P2₁/n, a = 1943.8, b = 940.8, c = 2015.6 pm, β = 109.87° and Z = 4 resp. The NMR spectra are discussed and some IR data are communicated.     

Kristallstruktur von (Me4N)3[Ir(SCN)6], Schwingungsspektrum und Normalkoordinatenanalyse

Crystal Structure of (Me₄N)₃[Ir(SCN)₆], Vibrational Spectra and Normal Coordinate Analysis From a mixture of the linkage isomers [Ir(NCS)_n(SCN)_6–n]^3–, n = 0–2, pure [Ir(SCN)₆]^3– has been isolated by ion exchange chromatography on diethylaminoethyl cellulose. The X-ray structure determination on a single crystal of (Me₄N)₃[Ir(SCN)₆] (trigonal, space group R3, a = 14.838(2), c = 23.827(1) Å, Z = 6) reveals the presence of two crystallographically independent complex anions which C_3i symmetry correlates with the cation/anion ratio 3 : 1. The thiocyanate ligands are exclusively S-coordinated with the average Ir–S distance of 2.384 Å and the Ir–S–C angle of 106.4°. The torsion angles S–Ir–S–C are 17.5 and 42.1°. The IR and Raman spectra of the (n-Bu₄N) salt are assigned by normal coordinate analysis based on the molecular parameters of the X-ray determination. The valence force constant f_d(IrS) is 1.57 mdyn/Å.