Updated Analysis of Gallium Chelate and Vanadium Chelate Solutions with 4‐(2‐Pyridylazo)Resorcinol and Xylenol Orange

The characteristic factors of the gallium and vanadium chelates with the ligands 4(2pyridylazo)resorcinol (PAR) and xylenol orange (XO) have been determined with the aid of the principle of correction, which makes it possible to eliminate the influence of the surplus ligand in the solution of its chelate with methane (which makes calculation easier) and thereby provides a more acceptable method in comparison with others. The real molar coefficients of extinction of the chelates Ga and V with PAR and XO have been determined and a detailed calculation of the stoichiometric ratios of chelates has been made. The results have shown that the chelates formed have the following structure: Ga(PAR), Ga(XO), V(PAR)₂, and V(XO).     

A Spectroscopic Study of 2-[4′-(Dimethylamino)phenyl]-benzothiazole Binding to Insulin Amyloid Fibrils

The spectroscopic properties of 2-[4′-(dimethylamino)phenyl]-benzothiazole (BTA-2) in solution and in the presence of amyloid fibrils were investigated using absorption and fluorescence spectroscopy. Solution studies show that BTA-2 forms micelles in aqueous solutions, but that the dye can be solvated upon the addition of acetonitrile (CH₃CN). BTA-2 binds to amyloid fibrils in solution leading to a characteristic blue-shift in the emission spectrum and an increase in fluorescence intensity. However, in solutions with increasing CH₃CN concentration, there was a marked decrease in binding of the BTA-2 to fibrils. Studies demonstrating the effect of BTA-2 concentration on binding were performed. A comparison with the standard amyloid fluorescent marker, thioflavin T (ThT), showed that BTA-2 is more fluorescent, making it an excellent dye to label amyloid samples.     

[Cu(en)_2][KFe(CN)_6]·H_2O的磁性分析

合成了氰根桥联配合物[[Cu(en)2][KFe(CN)6].H2O,使用元素分析、红外光谱等对配合物进行了表征。首次通过对该配合物的磁化率测定表明金属离子通过氰根传递弱反铁磁作用,计算求得分子磁体χmT的实验值与理论值。并根据Curie-Weiss定律拟合获得居里常数C=0.42cm3.K.mol-1和顺磁居里温度=-0.54K。     

[Co(en)_3][Fe(CN)_6]·H_2O的磁性研究

合成了氰根桥联配合物[Co(en)3][Fe(CN)6]·H2O,使用元素分析、红外光谱等对配合物进行了表征。首次通过对该配合物的磁化率测定表明金属离子通过氰根传递弱反铁磁作用,计算求得分子磁体有效磁距μeff的实验值与理论值。并根据Curie-Weiss定律拟合获得居里常数C=0.45968emu·K/mol,顺磁居里温度θ=-8.23117K。     

Molecular structure and vibrational spectra of [2-Oxo-2-(4-acetyl) phenyl amino] ethylene methacrylate by density functional theory and ab initio Hartree–Fock calculations

The molecular geometry and vibrational frequencies of the [2-Oxo-2-(4-acetyl) phenyl amino] ethylene methacrylate (APEMA) were examined theoretically using the Hartree–Fock and Density function method (B3LYP) with 6-31G(d) basis set. The calculated geometrical parameters of the investigated molecule were compared with experimental data. Both the calculated structural parameters and vibrational frequencies are in good agreement with the available experimental data.     

First-principles Study on the Magnetic,Half-metal and Thermoelectric Transport Properties of Inorganic-Organic Hybrid Compounds [C4N2H12][Fe4Ⅲ(HPO3)2(C2O4)3]

The electronic structure, magnetic and half-metal properties of inorganic-organic hybrid compound [C₄N₂H₁₂][Fe₄^Ⅲ(HPO₃)₂(C₂O₄)₃] are investigated by using the full-potential linearized augmented plane wave (FPLAPW) method within density-functional theory (DFT) calculations. The density of states (DOS), the total energy of the cell and the spontaneous magnetic moment of [C₄N₂H₁₂][Fe₄^Ⅱ(HPO₃)₂(C₂O₄)₃] are calculated. The calculation results reveal that the low-temperature phase of [C₄N₂H₁₂][Fe₄^Ⅲ(HPO₃)₂(C₂O₄)₃] exhibits a stable ferromagnetic (FM) ground state, and we find that this organic compound is a half-metal in FM state. In addition, we have calculated antiferromagnetically coupled interactions, revealing the existence of antiferromagnetic (AFM), which is in agreement with the experiment. We have also found that [C₄N₂H₁₂][Fe₄^Ⅲ(HPO₃)₂(C₂O₄)₃] is a semiconductor in the AFM state with a band gap of about 0.40 eV. Subsequently, the transport properties for potential thermoelectric applications have been studied in detail based on the Boltzmann transport theory.     

Structural characterization,thermal, ac conductivity and dielectric properties of (C7H12N2)2[SnCl6]Cl2·1.5H2O

(C₇H₁₂N₂)₂[SnCl₆]Cl₂·1.5H₂O is crystallized at room temperature in the monoclinic system (space group P2₁/n). The isolated molecules form organic and inorganic layers parallel to the (a, b) plane and alternate along the c-axis. The inorganic layer is built up by isolated SnCl₆ octahedrons. Besides, the organic layer is formed by 2,4-diammonium toluene cations, between which the spaces are filled with free Cl^? ions and water molecules. The crystal packing is governed by means of the ionic N—H···Cl and Ow—H···Cl hydrogen bonds, forming a three-dimensional network. The thermal study of this compound is reported, revealing two phase transitions around 360(±3) and 412(±3) K. The electrical and dielectric measurements were reported, confirming the transition temperatures detected in the differential scanning calorimetry (DSC). The frequency dependence of ac conductivity at different temperatures indicates that the correlated barrier hopping (CBH) model is the probable mechanism for the ac conduction behavior.     

[Cu~ⅡEDTA]~(2-)与[Fe~Ⅱ(CN)_6]~(4-)反应产物的分子光谱研究

按1:1(摩尔比)混合[Cu EDTA]~(2-)和[Fe(CN)_6]~(4-)溶液(pH=8)时,得到一种深红棕色溶液。测定并讨论了此红棕色溶液的电予光谱和红外光谱,据此确定此溶液中生成了不太稳定的氰桥配合物——[EDTA Cu~Ⅱ—NC—Fe~Ⅱ(CN)_5]~(6-)。     

Theoretical studies of vibrational spectra of [N(CH3)4]2ZnCl4−yBry compounds with y = 0, 2 and 4

The infrared and Raman spectra of [N(CH₃)₄]₂ZnCl_4?yBr_y, where y = 0, 2 and 4, have been analyzed with ab initio calculations of the vibrational characteristics of constitutive polyhedra, tetramethylammonium [N(CH₃)₄]⁺ and [ZnCl_4?xBr_x]^2? (x = 0, 1, 2, 3 and 4) tetrahedra. The optimized geometries, calculated vibrational frequencies, infrared intensities and Raman activities are calculated using Hartree–Fock and density functional theory B3LYP methods with 3-21G, 6-31G(d) and 6-311G⁺(d,p) basis sets. Calculation of the root mean square difference δ_rms between the observed and calculated frequencies allows to give scaling factors and to deduce that the best agreements are obtained by B3LYP/6-311G⁺(d,p) for [N(CH₃)₄]⁺ and B3LYP/3-21G for [ZnCl_4?xBr_x]^2?. The present study establishes a strongly reliable assignment of the vibrational modes of [ZnCl_4?xBr_x]^2? tetrahedra based on comparison between experimental and ab initio calculations, both of the frequencies and the intensities of the Raman signals.     

Benzyl-para-di-[5-methyl-4-(n-octylamino) pyrimidin-2(1H)one] as an interferon beta (IFN-β) modulator

Molecular Diversity - IFN-β is a cytokine that plays a significant role in the immune system. Inhibition of IFN-β might be used as a therapeutic approach to treat septic shock. A...     

Crystal structure of cholesteryl 4-[4-(4-n-hexylphenylethynyl)-phenoxy]butanoate – a liquid-crystalline unsymmetric dimer

Cholesteryl 4-[4-(4-n-hexylphenylethynyl)-phenoxy]butanoate, which exhibits the phase sequence: Cr 119.3°C (42.4?J?g^?1) SmA 196.4°C (1.1?J?g^?1) TGB–N* 202.4°C (5.4?J?g^?1) I, crystallizes in the triclinic space group P1 with unit cell parameters: a?=?10.527(1), b?=?13.151(2), c?=?16.991(2)?Å, α?=?86.13(1)°, β?=?98.96(1), γ?=?105.43(1)°, Z?=?2. The crystal structure has been solved by direct methods using single-crystal X-ray diffraction data and refined to R?=?0.0618. There are two crystallographically independent molecules, I and II, in the asymmetric unit. In both the molecules the phenyl rings are planar. The dihedral angle between the two phenyl rings is 12.16° and 18.14° for molecules I and II, respectively. In both the molecules, the six-membered rings of the cholesterol moiety are conformationally very similar. However, pronounced differences are observed in the conformation of the five-membered ring, which is intermediate between half-chair and envelope in molecule I, and half-chair in molecule II. The packing of molecules in the crystalline state is found to be a precursor to the Smectic A phase structure. The molecules in the crystal are held together by van der Waal's interactions.     

Analysis of the Coriolis interaction between ν6 and ν4 bands of ethylene-cis-d2(cis-C2H2D2) by high-resolution FTIR spectroscopy

The Fourier transform infrared (FTIR) spectrum of the ν₆ band of ethylene-cis-d₂(cis-C₂H₂D₂) was recorded with a unapodized resolution of 0.0063 cm^?1 in the 990–1100 cm^?1 region. A total of 609 transitions were assigned to this band centred at 1039.7682 ± 0.0003 cm^?1. The ν₆ band was found to be coupled to the ν₄ band by a-type Coriolis resonance. Both perturbed and unperturbed transitions were assigned and fitted to give eight rovibrational constants with high accuracy for the v₆ = 1 state with a standard deviation of 0.00097 cm^?1 using a Watson’s A-reduced Hamiltonian in the I^r representation. From a rovibrational analysis of the Coriolis interaction between the ν₆ band and non-infrared active ν₄ band of cis-C₂H₂D₂, the band centre of ν₄ at 984.9 ± 0.2 cm^?1 was derived. Furthermore, the second-order a-type Coriolis coupling constant between the two bands was obtained for the first time.     

1H and 13C n.m.r. Conformational Analysis of Adrenergic Drugs. Part 2. N-Isopropyl-N- {3-[4(4-Methoxybenzoylamino)Phenoxy]-2-Hydroxypropyl} Ammonium Chloride,a New β1-Blocking Agent

Abstract

Dynamic and structural features of N-Isopropyl-N- {3-[4(4-Methoxybenzoylamino)Phenoxy]-2-Hydroxypropyl} Ammonium Chloride in [²H₆]DMSO were investigated by measuring ¹³C and ¹H spin-lattice relaxation rates and ¹³C- {¹H} and ¹H- {¹H} n.O.e. Correlation times for main and internal reorientational motions were interpreted in terms of internal rotation around the two planal axes. Selective and double-selective ¹H spin-lattice relaxation rates were measured, wherefrom relevant proton-proton intramolecular distances were calculated. It was shown that the β₁? blocking agent assumes a preferred conformation where extensive intramolecular H-bonding prevents segmental motion along the quaternary ammonium sidechain.     

The FeH radical: rotational assignment of the a6A Δ(ν = 2) and b6II (ν = 1) levels

A dispersed fluorescence study of the FeH radical at near ambient (～450 K) temperature has identified the g⁶Φ-a ⁶δ (0, 2) and g⁶Φ-b⁶II (0, 1) bands in the orange region of the spectrum. The corresponding bands with upper state e⁶II are located at about 640nm in the red. High resolution measurements in LIF have enabled the assignment of around 275 lines to these four transitions. Analysis of these bands has provided a second vibrational interval for the a⁶δ state and a first vibrational interval for the b⁶II state as 1536cm^?1 and 1542cm^?1, respectively. Term values have also been measured for a set of levels with a tentative assignment to c⁴Φ_9/2 (ν = 1).     

Luminescent Properties of the Hexakis(Nitrito)Europate(Iii) Ion [Eu(No2)6]3−

Abstract

The 12-coordinated hexakis(nitrato)europate(III) ion displays a luminescence spectrum compatible with T_h, symmetry, with essentially a single emission line at 16 873 cm^?1 arising from the ⁵D₀→⁷F₁ transition. At low temperature (4.2 - 170 K), the lifetime of the ⁵D₀ level amounts to 10.9 ms and then sharply decreases because of vibrational de-excitation processes (E_a = 2 250 ± 1 490 cm^?1). The forbidden ⁵D₀→⁷F₀ transition displays an extensive pattern of Stokes and anti Stokes vibrational components and its energy reflects a nephelauxetic parameter for the nitrite ions δO(NO₂) equal to -14.4, slightly larger than the one associated to the nitrate ion in [Eu(NO₃)₆]^3-. The ligand excitation spectrum contains several bands displaying extensive vibrational structure mostly due to the δ(NO₂) vibrational mode.     

3-苯基-6-(4-甲苯基)-1,2,4-三唑[4,3-b]-1,2,4-三嗪晶体结构及其光电性能

为了开发稠环化合物3-苯基-6-(4-甲苯基)-1,2,4-三唑[4,3-b]-1,2,4-三嗪的光电性能,本文利用Gaussian程序研究了该化合物的晶体结构,采用密度泛函理论B3LYP方法选取6-31G(d)基组对其性能进行了量子化学计算研究,得到了稳定的几何构型和键长、键角且数据与实验值相符.从电荷转移、前线轨道能量和电子发射光谱等性质探讨了6位苯环上含有不同取代基时化合物性能的变化,含不同取代基时化合物分子的发射波长介于512～521 nm之间,并对含不同取代基化合物的光电性能进行分析.不同取代基以诱导和共轭效应协同作用于化合物上,通过改变电荷转移数量来影响化合物光电性能.根据计算结果预见该类化合物可以用来做光电材料.     

A Preliminary Investigation of the Complexation of Dopamine by p‐Sulfonated Calix[4, 6] Arene and β‐Cyclodextrin Using Fluorescence Spectrometry

The inclusion complexes of p‐sulfonated calix[4, 6] arene and β‐cyclodextrin with dopamine were studied by fluorescence spectrometry in aqueous media. It was found that the fluorescence intensity of dopamine regularly decreased upon the addition of p‐sulfonated calix[4, 6] arene, on the contrary, it increased upon the addition of β‐cyclodextrin. ¹H NMR spectra were applied to verify the formation of the complexes. According to the experimental results, 1:1 stoichiometry for the complexes was established and their association constants at 25°C were calculated by applying a deduced equation. Judging from the magnitude of their inclusion constants, the p‐sulfonated calix[4, 6] arene showed better inclusion capability than β‐cyclodextrin. The probable interaction mechanisms are proposed.