Crystal and molecular structure of deoxypeganine hydrochloride dihydrate

The crystal structure of deoxypeganine DOP chloride dihydrate (1) has been established by the x-ray structural method (diffractometer, CuK radiation, 671 reflections, direct method, R = 0.094). A comparative analysis has been made of the crystal structure of (1) with that of another complex of deoxypeganine (DOP) -DOP-ZnCl₂ ·2HCl.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from khimiya Priodnykh Soedinenii, No. 3, pp. 421–425 May–June. Original article submitted June 20, 1994.     

Crystal and molecular structure of benzoaza-12-crown-4 hydrochloride

Journal of Structural Chemistry - The X-ray crystallographic analysis of benzoaza-12-crown-4 hydrochloride crystals is performed for the first time: space group P1, a = 7.7497(4) Å, b =...     

Medium effects on fluorescence of ciprofloxacin hydrochloride

The medium (pH, organic solvents, cyclodextrin (CD) or surfactants) effects on the fluorescence of ciprofloxacin hydrochloride (CPFX.HCl) were studied in detail. It is found that the three acid constants of ciprofloxacin (CPFX) are near to each other. Therefore the relation curve between pH and fluorescence intensity has no strident change and keeps relative stable in the pH range of 2-7. When pH was in the range of 5.5-6.0, the fluorescence intensity of CPFX reached the max. The kind and amount of organic solvent added to the luminescent system have various effects. Ethanol quenched fluorescence and the fluorescence excitation wavelength is red shift at first and then blue shift. Acetone has complicated effects on the fluorescence properties of CPFX.HCl solution. The experiment result shows that acetone is really a quencher when its volume content in the system is from 0 to 20%, but when its content is 90%, the signal intensity is unexpectedly one and a half times as much as that of no acetone. This means that there is a strong interaction between the acetone and CPFX; CPFX.H(+) could be included into the gamma-CD but the capping effect is not notable. The effect of cationic surfactant cetyltrimethylammonium bromide and non-ionic surfactant TX-100 and TX-80 on CPFX fluorescence was unimpressive, but the anionic surfactant's effect is aberrant. The fluorescence intensity of CPFX.HCl solution experiences three stages of increasing, decreasing and increasing in turn, as sodium dodecyl sulfate is adding gradually. But for sodium lauryl sulfonate, there are only two stages of decreasing and increasing with the concentration increasing. It is problematic to illustrate clearly the effect mechanism of acetone and anionic surfactant at present. Undoubtedly, the experimental results in this paper should be useful in practice works and the research is worth studying still further.     

Crystal and molecular structure of the hydrochloride of the diterpene alkaloid hetisine

The molecular and crystal structure of hetisine hydrochloride has been obtained and compared with those of the hydrobromide and perchlorate salts. These structures have been investigated as coordinatoclathrates and it has been shown that on changing from chloride to bromide and then to perchlorate a morphotropic transition is observed.Supplementary Data relevant to this article have been deposited with the British Library as Supplementary Publication No. SUB 82140 (9 pages).     

分子印迹-后化学发光法测定盐酸环丙沙星

以α-甲基丙烯酸为功能单体、乙二醇二甲基丙烯酸酯为交联剂合成了盐酸环丙沙星分子印迹聚合物, 并制备了在线富集发光流通柱. 建立了环丙沙星-Ce(Ⅳ)-亚硫酸体系的分子印迹-化学发光分析法. 盐酸环丙沙星浓度在5×10-7～5×10-5 mol/L 范围内与发光强度呈线性关系, 方法的检出限为5.2×10-8 mol/L. 方法已用于尿与鲅鱼样品中环丙沙星的检测.     

An axial t-butyl group: Crystal structure of 1-phenyl-c-4-t-butyl-r-cyclohexylpiperidine hydrochloride

The structure of 1-Phenyl-c-4-t-butyl-r-cyclohexylpiperidine hydrochloride $\text{1}$ is shown by X-ray crystallography to have an axial t-butyl group. The conformational deformations. are smaller than expected except for the outward bending of the alkyl substituent with a concomittant flattening of the corresponding half part of the chair.     

光散射分析技术测定盐酸环丙沙星含量

在pH 4.6的乙酸-乙酸钠缓冲溶液中,环丙沙星能与四苯硼钠作用生成沉淀产生光散射信号(LS)能应用普通荧光分光光度计检测,从而建立了环丙沙星的光散射分析法.LS光谱在385.0 nm处,具有特征散射峰,且增强的光散射强度(ΔILS)与0.03～0.2 μg/mL,0.2～2.5 μg/mL两个范围内的环丙沙星溶液呈线性关系,相对应的检出限分别为7.4,2.7 ng/mL.本实验中研究了酸度、聚乙二醇600溶液的浓度、四苯硼酸钠溶液的浓度以及共存物质对LS强度的影响.方法已用于盐酸环丙沙星片剂中环丙沙星的测定,RSD为0.3%～0.6%.     

Simple and cost-effective determination of ciprofloxacin hydrochloride by electrical micro-titration

By employing an electrical micro-titration system, in which a capacitively coupled contactless conductivity detector(C4D) was used to monitor the reaction process in real time, herein a novel method for determining ciprofloxacin hydrochloride(CIPHCl) was developed for the first time. Mode 1: Standard CIPHCl solutions at different concentrations were loaded into reaction cells, respectively, and were titrated with standard Ag+. Upon the titration, the formation of a precipitate alters the number of ions in the solution, raising the change of conductivity, which was monitored by a special C~4 D to construct a titration curve. The endpoint of the titration was located from the peak of the curve. Between the elapsed time and the initial concentration of titrand, a linear relationship was established over the range of2.0–8.0 mmol/L. Mode 2: Standard Fe~(3+) took the place of Ag~+, and was used as titrant to recognize ciprofloxacin contributed to the formation of complexation, which also resulting a change of solution conductivity. Under optimized conditions, a working range of 1.0–5.0 mmol/L CIPHCl was found. Because the reaction solutions were isolated from the working electrodes, this pioneer work shows significant simplicity and cost-effectiveness, by eliminating the requirements for detector exchange/renewal between different measurements, and by involving no auxiliary chemicals. Both of the two approaches were applied successfully to determine CIPHCl in tablet samples. And the results were in good agreement with those obtained by reference method.     

Crystal and molecular structure of 2-chloro-1-methyl-4-phenyl-α-carboline hydrochloride

A compound with the composition C₁₈H₁₆Cl₂ON₂ was subjected to an x-ray diffraction study. All of the rings in themolecule are planar. Both of the six-membered rings of the carboline system are inclined slightly and identically with respect to the central pyrrole ring, forming angles of 3 ° with it and 6 ° with one another. The phenyl ring is turned at an angle of 52.7 ° relative to the average plane of the carboline system.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp, 779–782, June, 1984.     

Crystal structure of dibenzoyl diselenide.

C14H10O2Se2 is monoclinic, P2(1)/c. The unit-cell dimensions at 293 K are a = 12.795(2), b = 12.126(2), c = 9.0179(13)A, beta = 107.074(6)degrees, V = 1337.5(3)A3, and Z = 4. The R value is 0.048 for 2319 observed reflections. The dihedral angle between the plane C4-C7(O2)-Se1 and C9-C8(O1)-Se2 is 85.6(2)degrees, keeping the Se atom unshared electron pairs in a more stable configuration with the rest of the molecule. The packing in the crystal is entirely due to van der Waals forces.     

The 7.25-hydrate oftert-butylamine. A semi-clathrate and complex variant of the cubic 12 Å structure type

Of the various hydrates oftert-butylamine, the title compound has been identified as the second-highest, melting incongruently at –19°C. Its crystal structure (orthorhombic, space groupPca2₁,Z=32 formula units per unit cell,a=24.80,b=16.440,c=25.29 Å) and the exact composition have been determined from X-ray diffraction at –150°C. The hydrate is a rather complex semi-clathrate, with the amine molecules not merely encaged, but also hydrogen-bonded, in a three-dimensional water host structure, which in turn is not fully four-connected. Nevertheless, it bears a clear relationship to the basic and genuine clathrate-hydrate cubic 12 Å type.Dedicated to Professor G. A. Jeffrey on his 80th birthday. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82196 (8 pages).Part 14 of the seriesHydrates of Weak and Strong Bases; for part 13 see [1].     

Crystal structures of vasicinone and peganidine hydrochloride

Crystal structures of the alkaloids vasicinone and peganidine hydrochloride were studied by x-ray structure analysis. The configurations of asymmetric centers C4 and C9 in peganidine were determined. The hydroxyl and acetonyl groups were mutually syn-positioned relative to the tricyclic plane. H-bonds involving the Cl ion, which connected molecular cations transformed by 2₁ screw axes, were formed in the peganidine hydrochloride crystal. H-bonds between the C4 carbonyl and the C9 hydroxyl transformed by a glide plane were formed in the vasicinone crystal. The N1 atom was not involved in forming intermolecular H-bonds.     

Crystal structure of zwitterionic trimethylammoniopropane sulfonate.

Crystal structure of zwitterionic trimethylammoniopropane sulfonate (Z1-Methyl) was determined by single-crystal X-ray diffractometry. Z1-Methyl crystallized in the monoclinic system, space group P2(1), with a = 6.3639(2), b = 10.9237(4), c = 8.1505(4) A, beta = 111.078(2) degrees, V = 528.69(4) A3, Z = 2. An inter-molecular ionic association was observed in the crystal. The shortest distance between the methyl protons of the trimethylammonium group and the oxygens of the sulfonate group was 2.51(2) A.