Syntheses and structures of two acridine orange polyiodide salts

Polyiodide salts of acridine orange were isolated from solutions of an acridine and I₂ in methylene chloride, ethanol, and acetone. The products from all solutions were found to contain both amorphous and crystalline material. The isolated crystalline product from methylene chloride and ethanol were identical (1), but the product isolated from acetone was different (2). Complex 1 was formulated as [C₁₇H₁₉ N ₃(H)]₂(I)₂ 3I₂. It crystallizes in the monoclinic space group P2₁/n, with a = 9.082(2) Å, b = 24.027(4) Å, c = 10.683(1) Å, = 107.20(1), and D _(calc) = 2.31 Mg/m³. Complex 2 was formulated as [C₁₇H₁₉ N ₃(H)]I₃. It crystallizes in the triclinic space group P – 1, with a = 10.498(2) Å, b = 11.265(2) Å, c = 9.287(1) Å, g 100.88(1), = 94.57(1), = 102.10(1), and D _(calc) = 2.05 Mg/m³.     

Infrared and raman spectra of 2,4,6-trichlorobenzonitrile

The infrared and Raman spectra of 2,4,6-trichlorobenzonitrile have been measured in the solid state and in solution. A complete vibrational assignment based on aC _2v symmetry was made using the Raman polarization data and by comparison with the spectra of benzonitrile. In the solid state, the spectra are consistent with the centrosymmetric monoclinic structure reported for the molecule. Thermodynamic functions have been calculated for the temperature range 1500-200 ° K for a rigid-rotator harmonic oscillator approximation.     

Reflection Spectra of the Crystalline Electron Donor-Acceptor Complexes of TCNQ

The polarized reflection spectra were measured on the crystals of TCNQ complexes with phenothiazine, anthracene, pyrene, acenaphthene, carbazole, hexamethylbenzene and 1,10-phenanthroline. The crystalline absorption spectra have been obtained by the K-K transformation of the reflection spectra. The charge transfer degree and the stabilization energy in the ground state were estimated for each complex by analysing the CT bands in the solid state.     

Structure of monoclinic acridine orange hydrochloride monohydrate,C17H19N3 · HCl · H2O

M_r = 319.82, monoclinic P2₁/a, Z = 4, a = 14.545(5), b = 15.562(6), c = 8.538(4) Å, β = 120.66(3)°, V = 1662(1) ų, D_m = 1.27 Mgm⁻³, D_x = 1.278 Mgm⁻³, λ(MoKα) = 0.71069 Å, μ(MoKα) = 0.24 mm⁻¹, T = 297 K. Final R = 0.049 for 1485 observed reflections. All hydrogen atoms were located and refined isotropically. Bond lengths (σ = 0.004 Å) and angles (σ = 0.3°) are normal. The substance is a derivative of acridine. The structure consists of chloride anions, bisdimethylaminoacridinium cations and water molecules. In the solid state the molecules are approximately planar. Pairs of cations form dimers with parallel planes connected by an I inversion centre and plane distances of 3.474 Å. They overlap with partial areas of all three six membered rings.     

A Comparison of the High Resoluton Crystal Structures of the π- Molecuar Complexes of Anthracene and Phenothiazine with Pyromellitic Dianhydride

The π-molecular complexes formed by aromatic molecules with three rings tend to form crystals of high purity and are therefore ideal for solid state spectroscopic and photocurrent studies. We have therefore undertaken an investigation of the detailed structures of a number of such complexes in order to facilitate the interpretation of such data and other physical properties and in order to better understand the large changes in physical properties generated by small changes in composition and molecular packing. The piezoreflection spectra of the anthracene-pyromellitic dianhydride complex (A-PMDA) has been studied by Eckhardt and Merski (1973). The photo-current excitation spectra of A-PMDA was reported by Karl and Ziegler (1975) and more recently the preparation, optical properties, absorption and photoconductivity properties of phenothiazine-pyromellitic dianhydride have also been studied. (Anthonj, Karl, Robertson and Stezowski, 1979).     

单壁碳纳米管径向形变对介电常数和吸收光谱的影响

采用广义梯度近似方法中的PBE(J. Perdew、K.Burke和M. Ernzerhof)技术,对结构为(10,0)的锯齿型单壁碳纳米管在径向发生0.0～0.5扁率时的介电常数ε和光谱特性进行了理论研究.结果显示:(10,0)型单壁碳纳米管的径向形变对其介电常数峰值及光谱峰值的大小、位置和频率范围都有较大的影响.当入射光偏振方向垂直管轴时,介电常数峰值向低频区偏移,光谱峰值则依赖于初始位置.当入射光的偏振方向平行于管轴时,主要特征是介电常数幅值的变化和光谱范围的拓宽,同时,介电常数峰值向低频区偏移.     

Vibrational spectra and thermodynamic properties of 2,4,6-tribromobenzonitrile

The infrared and Raman spectra of 2,4,6-tribromobenzonitrile have been recorded in the solid state and in solutions. Assignments of the fundamental vibrations based on Raman polarization data and comparison with the spectra of benzonitrile and its trichloro derivative are given and discussed. The thermodynamic functions have been evaluated for a rigid-rotor harmonic oscillator approximation at several temperatures.     

Laser action and upconversion of Nd3+ in tellurite bulk glass

Laser action together with upconversion processes that produce green, orange, and red emissions in Nd³⁺-doped tellurite glass (TeO₂–TiO₂–Nb₂O₅) have been investigated. The upconversion processes were conducted in such a way that the dynamics of the visible fluorescence was analyzed under lasing and nonlasing conditions. The features observed in the time resolved upconverted emission show the existence of excited state absorption of both pump radiation and laser emission.     

Preparation and investigation of (CuInSe2)x(2ZnSe)1‐x and (CuInTe2)x(2ZnTe)1‐x solid solution crystals

The (CuInSe₂)_x(2ZnSe)_1‐x and (CuInTe₂)_x(2ZnTe)_1‐x solid solution crystals prepared by Bridgman method and chemical vapor transport have been studied. The nature of the crystalline phases, the local structure homogeneity and composition of these materials have been investigated by X‐ray diffraction (XRD) and Electron Probe Microanalysis (EPMA) methods. The analysis revealed the presence of chalcopyrite‐sphalerite phase transition between 0.6 ≤ X ≤ 0.7. Lattice constants, value of σ position parameter and bond length between atoms were also calculated. It was found that the lattice parameters exhibit a linear dependence versus composition. The transmission spectra of solid solution crystals in the region of the main absorption edge were studied. It was established that the optical band gap of these materials changes non‐linearly with the X composition. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

3-Aryloxypropiononitriles Intermediates: Crystal and Molecular Structure of 2- and 4-(2-Bromoethoxy)diphenylmethanes

The crystal structure of 2- and 4-(2-bromoethoxy)diphenylmethanes ( I and II respectively), intermediates in a novel synthesis of substituted 3-aryloxypropiononitriles, have been determined by single crystal X-ray diffraction at room temperature (r.t.) and at 150K. No significant changes in the crystal structure of I and II have been observed in going from r.t. to 150K. In both compounds the bromoethoxy group presents a gauche conformation and shows a short Br.O intramolecular interaction that allows to explain the very good reaction yields obtained in the novel synthesis. The three-dimensional structure of I is stabilized by two intermolecular hydrogen bonds and that of II by six. This difference in the crystal packing of I and II explains the variation in the m.p. The analysis of ¹H and ¹³C NMR spectra suggests that the molecular conformations in solution are similar to those found in solid state.     

First-principles calculations of the V3+ absorption spectra in LiAlO2 and LiGaO2

The systematic first-principles analysis of the energy level schemes and ground state absorption (GSA) of the V³⁺ ion in two oxide crystals LiAlO₂ and LiGaO₂ was performed. The recently developed first-principles approach to the analysis of the absorption spectra of impurity ions in crystals based on the discrete variational multi-electron method (DV-ME) [K. Ogasawara, T. Iwata, Y. Koyama, T. Ishii, I. Tanaka, H. Adachi, Phys. Rev. B 64 (2001) 115413] was used in the calculations. The method is based on the numerical solution of the Dirac equation; no phenomenological parameters are used in the calculations. As a result, complete energy level schemes of V³⁺ ion and its absorption spectra in both crystals were calculated, assigned and compared with experimental data.     

Magnetic properties and sensitized visible and NIR luminescence of DyIII and EuIII coordination polymers by energy transfer antenna ligands

Two coordination polymers, {[Ln(2-stp)(4,4′-bipy)(H₂O)].(H₂O)}, [Ln = Dy (1) and Eu (2), 2-stp = 2-sulfoterephthalate and 4,4′-bipy = 4,4′-bipyridine] have been characterized by solid state UV-vis, FTIR spectra, X-ray single crystal diffraction and solid state photoluminescence. Variable-temperature magnetic susceptibility and isothermal magnetization as function of external magnetic field is also studied for both complexes. After ligand-mediated excitation, both complexes show the characteristic visible and NIR luminescence of the corresponding Ln^III ions (Ln = Dy, Eu) which is due to efficient energy transfer from the ligands to the central Ln^III ions via an antenna effect. The indirect energy transfer in both complexes has been investigated and discussed in detail.     

Influence of γ-Irradiation on Some Properties of NaCl: Eu++ Crystals (I). Optical and Dielectrical Characteristics of the Dopant Ions

The present work opens a series of papers describing a variety of properties of the same material, and deals with the effect of Eu⁺⁺ ions, and y–irradiation on the optical and dielectrical characteristics of NaCl crystals. For nonirradiated crystals four types of Eu⁺⁺-related absorption spectra have been identified and correlated with I.V. dipoles and three types of precipitates stable in the well aged crystals. For the solution—treated samples the effect of irradiation was to diminish the concentration of I.V. dipoles and to change the absorption spectrum in a remarkable way. These changes are explained in terms of the formation of some dopant—related clusters different of those obtainable thermally. No spectroscopic evidences have been obtained for the radiation—induced changes of the valence state of the dopant irrespective of its dispersion degree.     

Time resolved valence band photoelectron spectroscopy of liquid palladium and molybdenum

Photoelectron spectroscopy measurements on liquid transition metals are not feasible by conventional steady state experiments because of the elevated vapor pressures of these metals at the melting point. However, dynamic experiments with surface melting induced by pulsed laser irradiation combined with time resolved photoelectron spectroscopy make these experiments possible for the first time. Valence band spectra of Pd and Mo have been obtained by this method in both the high temperature solid phase and the liquid phase under identical experimental conditions. Both the elements reveal distinct changes in the valence band spectra on melting. The shapes of the 4d bands of the two metals in the liquid phase are in good agreement with the calculated spectra based on the ab initio density of states (DOS) calculations.     

基于构象灵活的N-杂环配体构筑的3D拟卤化亚铜配合物的合成、结构和性质研究

溶剂热条件下,通过无机阶梯状链[Cu(SCN)]_n与柔性有机配体1,3-二(4-吡啶基)丙烷(bpp)自组装,得到了一例新型的3D有机-无机杂化配合物[Cu₄(SCN)₄(bpp)₂]_n (1)。值得关注的是,不对称单元中的bpp配体显示两种不同的构象(trans-gauche或trans-trans),并连接梯形的[Cu(SCN)]_n链形成结晶学独立的[Cu₂(SCN)₂(bpp)]_n (A和B)层。紧接着, 两个不同的层通过ABB′A′的顺序排列形成独特的三维褶皱结构。进一步对配合物1进行了红外光谱(FT-IR)、粉末衍射(PXRD)、热分析、固体紫外-可见漫反射光谱(UV-Vis)和光致发光性质研究。固体紫外-可见光谱表明配合物在紫外区有强的吸收并且具有半导体性质,带隙能E_g为3.20 eV。光催化性能测试结果表明,配合物1在紫外光照射下对中性红(NR)、甲基橙(MO)、天青I(AI)、亚甲基蓝(MB)和亮蓝(ED)这五种染料表现出不同的光催化活性,这可能与有机染料的尺寸和电荷差异有关。此外,荧光测试表明配合物在室温下表现出较强的绿色发光性质,在525 nm附近有强的荧光发射峰。这种发射可能与配体中心激发态有关,可能涉及金属到配体或配体到配体的电荷转移。     

Tautomeric investigations and crystal structure analysis of chlorzoxazone

The crystal structure and infrared spectra of the compound has been reported. Infrared spectra of the compound were examined in various solvents. The results of the crystal structure analysis and IR spectra assignments showed that the compound has the amino tautomeric form in the solid state and in studied solutions.     

d-f and f-f transition bands of praseodymium and samarium ions in silica glasses

d-f and f-f transition bands of Pr and Sm ions in silica glasses have been studied by the absorption, excitation and emission spectra. In particular, Sm-doped silica glasses were treated with different atmospheres around the T_g temperature. The change of the valency state and the transition band shown after the treatments are discussed.     

Growth and high frequency dielectric study of pure and thiourea doped KDP crystals

Non linear optical (NLO) materials have acquired new significance with the advent of a large number of devices utilizing solid‐state laser sources. Several NLO materials have been used for this kind of technological applications. The Potassium di‐hydrogen phosphate (KDP) one of NLO material having superior non linear optical properties has been exploited for variety of applications. In the present investigation we have grown KDP crystals from aqous solution with thiourea, an organic non linear optical material. We could enhance the SHG efficiency of thiourea doped KDP crystal. It was 1.99 times more that of pure KDP. We observed more enhancements in nonlinearity for low concentration of thiourea.The crystal structure and cell parameters of grown crystal were determined from Powder XRD.The incorporation of thiourea in the grown crystals was qualitatively analyzed from FT‐IR study. The absorption spectra of pure and thiourea doped KDP crystal reveal that thiourea doped KDP crystals would be a better nonlinear optical (NLO) material for second harmonic generation (SHG) than pure KDP. The thermal decomposition and weight loss of pure and thiourea doped KDP crystal was observed by thermogravimetric (TGA) analysis and Differential Scanning Calorimetry (DSC). The high frequency dielectric study of pure KDP crystal, thiourea doped KDP crystals and organic additive thiourea was carried out using X‐band at frequency 8GHZ and 12GHZ by transmission line wave guide method. We observed low dielectric constant of thiourea doped KDP crystal when it is doped with 2mole% of thiourea. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Single crystals growth and absorption spectra of Cr-doped Al2−xInx(WO4)3 solid solutions

The growth conditions of pure and Cr³⁺-doped Al_2−xIn_x(WO₄)₃ single crystals, using top-seeded solution growth (TSSG) technique, have been studied. A series of experiments have been performed at different In concentrations, x=0.0, 0.3, 0.6 and 1.0, as well as at different concentrations of Cr³⁺ (0.0, 0.1, 0.2, 0.5 and 1.0) in at% with respect to the initial total concentration of Al and In in the starting solutions. The basic parameters of the crystal growth are varied over a wide range: seed orientation, speed of rotation, axial and radial temperature differences in the solution and the solution cooling rate. The investigated relations between the basic defects in the crystals and these parameters result in determination of the optimal conditions for growth of defect-free crystals. Distribution coefficients of Al, In and Cr have been determined, so the growth of crystals with given compositions is possible. Values of Dq/B (crystal field strength) for the various crystal compositions are calculated from the optical absorption spectra. The calculated values show that the discussed solid solutions have weak crystal field and are suitable for media with broadband emission spectra.     

Influence of Substituents in the Solid State of Radical Cations of Two Phenothiazine Derivatives

The optical, EPR and magnetic susceptibility of the cation radicals of two phenothiazine derivatives have been investivated as a function of R₂ and R₁₀ substituents. We have tried to relate all of the above with the conductivity of these compounds and their slight dependence of the conductivity on the temperature. The diffuse reflectance spectra show a charge transfer between 600 adn 1200 nm. This CT band shows the R₂ and R₁₀ substituents influence. The EPR shows the existence of the radical cation and the dependence of the bandwidth on the R₁₀ subsituents. X static measurements give different quantities of free unparied electrons on each radical in the solid state, also related to the R₁₀ substituents.