Chloroform-ethanol Mixture Research Articles

Investigation of hexakis[2-formylphenoxy]cyclotriphosphazene structure by single crystal X-ray diffraction and computer simulation

Crystallization of hexakis [2-formylphenoxy]cyclotriphosphazene was carried out from its melt and its solution. It was found that single crystals of this compound could be obtained via the slow crystallization from a chloroform–ethanol mixture. The melting point of such crystals was determined by the DSC method. These crystals have been for the first time investigated using the single crystal X-ray diffraction analysis. It was found that the phosphazene cycle in hexakis [2-formylphenoxy]cyclotriphosphazene is not planar in contrast to the starting hexachlorocyclotriphosphazene. The results acquired by X-ray diffraction were used in theoretical calculations of the characteristics of molecule. It was revealed that the spatial configuration of substituents in hexakis [2-formylphenoxy]cyclotriphosphazene is highly symmetrical towards the phosphazene cycle. There are π-stacking interactions between some aromatic cycles. The molecular framework is formed mainly by the C⋯H, C⋯C and H⋯H intramolecular interactions. A deformation of the phosphazene cycle arises due to asymmetric intramolecular hydrogen bonds between the nitrogen atoms of phosphazene cycle and the hydrogen atoms of aromatic rings. Performed structural calculations revealed the diameter of a sphere circumscribing the phosphazene molecule, which was 1.5 nm. These results of structural investigations may be of interest for the molecular design, theoretical prediction of the properties of new compounds, synthesis of coordination compounds, and nanotechnology.

VAPOR-LIQUID EQUILIBRIUM DATA OF CHLOROFORM-ETHANOL MIXTURES INSIDE POLAR AND NONPOLAR POROUS PLATES

Vapor-liquid equilibrium (VLE) data of chloroform-ethanol mixtures at different temperatures were experimentally measured in 3 different macroporous plates: a 13.5-μm pore diameter, sintered, stainless-steel plate; a 30-μm pore diameter, porous, carbon plate; and a 30-μm pore diameter, porous, Teflon plate. The experimental results showed that the VLE of this system in the stainless steel plate was dramatically altered and the azeotropic point was eliminated. However, the effect of the porous Teflon plate or porous carbon plate on the VLE of this system was insignificant. The VLE for the studied system was predicted through the theory of Abu Al-Rub and Datta and gave a good agreement with the experimental data.

Preparation and characterization of porous poly(methacrylic acid) gel by dispersion polymerization

Porous poly(methacrylic-co-glycidylmethacrylate) (MAA-GM) was prepared by dispersion polymerization using benzoyl peroxide as an initiator and methacrylate terminated phthalate glycol polyester as a steric stabilizer in polar organic medium (chloroform–ethanol mixture). The prepared poly(methacrylic acid) dispersion was crosslinked by glycidylmethacrylate oligomers. The crosslinked copolymer (MAA-GM) was base hydrolyzed using hydroxyl amine, sodium methoxide, and triethyl amine. The metal binding behavior of the prepared polymer was examined by means of atomic absorption spectrophotometer. The thermal stability of the prepared polymers was examined by thermal gravimetric analysis (TGA). © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1793–1798, 1999

Inferring unresolved hyperfine structure in liquid solution EPR:14N hyperfine structure in the 1∶1 copper-calcimycin complex

Theoretical expressions for EPR line widths in liquids suggest the following two strategies for inferring unresolved hyperfine structure in near square planar copper(II) complexes and thereby identify the coordinating ligand atoms: (i) Increasing the resolution by reducing the line widths, by forming a mixed ligand complex of lower magnetic anisotropy. (ii) By demanding that the magnetic anisotropy determined from line widths, assuming unresolved hyperfine structure, should agree with that determined from frozen solution EPR spectrum.14N hyperfine structure from a coordinating cal (A N ∼ 12 G) in 1∶1 copper-calcimycin complex (Cu−cal) has been observed / inferred by the application of these strategies in 1∶1 chloroform-ethanol mixtures. It has been suggested that Cu−cal prepared in the presence of the bidentate ligand diethyldithiocarbamate (dtc−) is the mixed ligand complex Cu(dtc)(cal) in which cal is a bidentate ligand. The Cu−cal prepared in the presence of a monodentate anion AN (AN=NO 3 − , Br−, Cl− etc.) is Cu(AN)(cal) in which cal is a tridentate ligand. These complexes have near planar coordination geometry.

Co-ordination chemistry of 1,4-bis(o-aminobenzyl)-1,4-diazacyclohexane (L) with nickel(II), copper(II) and palladium(II)

1,4-bis(o-aminobenzyl)-1,4-diazacyclohexane (L) has been synthesized and its co-ordination chemistry with nickel(II), copper(II) and palladium(II) investigated. The reaction of L with Ni(ClO4)2·6H2O in a chloroform–ethanol mixture affords orange, diamagnetic [NiL][ClO4]21 which consists of the square-planar dication [NiL]2+ in the solid state and in weakly or non-co-ordinating solvents (nitromethane, acetone). In co-ordinating solvents (acetonitrile, pyridine, dimethylformamide) or in the presence of co-ordinating anions (NCS–) blue solutions of 1 are obtained from which blue, paramagnetic species were isolated as crystalline materials: [NiL(NCS)2]2 and [NiL(MeCN)2][ClO4]2·1.5 MeCN 3. Complex 2 was shown by X-ray crystallography to consist of neutral, octahedral [NiL(NCS)2]. Using Ni(NO3)2·4H2O as starting material both square-planar, orange [NiL][NO3]24a and blue, octahedral [NiL(NO3)2]4b containing two monodentate NO3– ligands were isolated. Reaction of L with Cu(ClO4)2·6H2O and Cu(NO3)2·4H2O in CHCl3–EtOH produced blue crystals of square-planar [CuL][ClO4]25 and five-co-ordinate [CuL(H2O)][NO3]2·H2O 7, respectively. Recrystallization of 5 from MeCN produced blue crystals of [CuL][ClO4]2·2MeCN 6. Palladium(II) acetate reacts with L in CHCl3–EtOH affording orange-brown crystals of [PdL][ClO4]28. The crystal structures of 1, 2, 5, 7 and 8 have been determined by X-ray crystallography. In the solid state the ligand is always equatorially co-ordinated in a transoid fashion where one of the two [graphic omitted]aniline chelate rings adopts a boat and the other a twist-boat conformation. This has been corroborated by solid-state 13C cross-polarization magic angle spinning NMR spectroscopy of 1 and 8.

Solvent Effects on Gel Characteristics of Conducting Polymer

The response time of volume change of poly(3-alkylthiophene) gel film is dependent on both film size and solvent used; that is, it becomes longer with increasing film size and shorter in a solvent of larger Taft parameter ?*, respectively. In chloroform-ethanol mixture, the response time becomes longer with increasing ethanol concentration. Poly(3-alkylthiophene) gel expanded in chloroform shrinks upon introduction of alcohol above the critical concentration and also with decreasing temperature below a critical temperature. The critical temperature increases with increasing concentration of alcohol. In terms of concentration dependence of volume change, the critical concentration of alcohol depends on the kind of alcohol used. That is, alcohol (CnH2n+1OH) with larger carbon number n exhibits larger critical concentration. These results are discussed in terms of the interactions between alkyl chains and solvent molecules and also between main chains and solvent molecules.

Preparation of enantiomerically pure 1,1'-binaphthalene-2,2'-diol and 1,1'-binaphthalene-2,2'-dithiol

A practical preparation of enantiomerically pure 1,1'-binaphthalene-2,2'-diol (1) and 1,1'-binaphthalene-2,2'-dithiol (2) is reported. Enantiopure 2 is obtained from enantiopure 1 via Newman-Kwart rearrangement of the thiocarbamoyl derivative 5 under controlled reaction conditions. The enantiopure starting diol 1 was obtained by a simple and inexpensive method engaging condensation of thiophosphoryl chloride and (S)-(-)-α-methylbenzylamine in pyridine and reaction of the resulting phosphoramidate 3 with racemic binaphthol 1 to give quantitatively a 1:1 mixture of diastereoisomers 4 that were cleanly separated by a single recrystallization from a chloroform-ethanol mixture in very high yield

Preparation and properties of β-galactosidase confined in cells of Kluyveromyces sp.

Lactase (β- d-galactosidase EC 3.2.1.23) was immobilized in yeast cells of the genus Kluyveromyces. Comparison of various solvents or polycations led to the selection of a chloroform-ethanol mixture for cell permeabilization. The lactase was confined inside the ghosts, with a minimum deactivation, by treatment with 0.4% glutaraldehyde. The combined procedure, permeabilization by chloroform-ethanol and confinement by glutaraldehyde, was applied to strain, K. lactis CBS 683, yielding a biocatalyst with an activity of 3.8 units ONP per milligram dry weight as calculated from V max. The biocatalyst could be stored in suspension at 4°C for 14 months with 20% deactivation. The K m, 4.2 m m, was comparable to the values published for the free enzyme, and the biocatalyst was found free of diffusion limitation for the hydrolysis of ONPG in the range of concentration from 0.3 to 50 m m. The pH activity profile showed a sharp optimum around pH 6.5; the storage stability in buffer at 35°C was very good for pH values above 6.1. The biocatalyst was used and recovered by centrifugation seven times without loss of activity, for the hydrolysis of 5% lactose solution in buffer at 30°C, with a conversion of about 80%.

Determination of Doxorubicin, Daunorubicin and some of their Metabolites in Mouse Plasma by High-Performance Reversed-Phase Liquid Chromatography with Amperometric Detection

Abstract A selective and sensitive reversed-phase liquid chromatographic method with electrochemical detection for the analysis of doxorubicin, daunorubicin and some of their metabolites in plasma is reported. A mobile phase consisting of acetonitrile-phosphate buffer solution-tetrahydrofuran (25–71,5–3,5) flowing at 1 ml/min through a Lichrocart RP 18 column was employed. The influence of various parameters on the separation (solvent composition, pH, tetrahydrofuran content) has been examined. An extraction of anthracyclines from plasma was performed using chloroform-ethanol mixture (4: 1) with high extraction efficiency; reproducible results were attained by working with a 1 M phosphate buffer which ensured a real buffering of the plasma samples. The sensitivity of amperometric detection makes this method suitable for analyzing small amounts of the parent drugs and their metabolites. The precision was better than 4% in the range 0.2 to 5 μg/ml plasma.

Analysis of bilirubins in biological fluids by extraction and thin-layer chromatography of the intact tetrapyrroles: application to bile of patients with Gilbert's syndrome, hemolysis, or cholelithiasis.

A method was developed to extract quantitatively the bilirubins from bile, urine, serum, stool, and preparations from liver with a chloroform-ethanol mixture at pH 1.8 in the presence of ascorbic acid and NaCl. Extracted pigment was submitted to thin-layer chromatography, and the separated bilirubins were either immediately eluted and determined spectrophotometrically or individually converted to ethyl anthranilate azo derivatives for thin-layer chromatographic analysis of each isolated pigment band. Bilirubins in duodenal bile of eight healthy adults comprised 1.5 +/- 1.3% unconjugated bilirubin-IX alpha, 69 +/- 6% bilirubin diglucuronide, and 16 +/- 4% bilirubin monoglucuronides. Mixed diconjugates containing one glucuronosyl moiety and either one xylosyl or one glucosyl group amounted to 10 +/- 3%. Most samples (6 of 8) contained trace amounts (0.6 +/- 0.6%) of unconjugated bilirubin-IX beta, in agreement with nearly exclusive cleavage of heme at the alpha-meso position. The composition of the bilirubins in bile was normal in 6 patients with cholesterol gallstones, 4 with chronic hepatitis, and 3 with hemolysis. In duodenal bile of individuals with Gilbert's syndrome (n = 10), the concentration of bilirubin conjugates was comparable to that in healthy adults, but the proportion of bilirubin diglucuronides (52 +/- 8%) was decreased. The concentration of unconjugated bilirubin-IX alpha showed a fair positive correlation with that of bilirubin monoglucuronide and was increased in half of the patients with Gilbert's syndrome.

ChemInform Abstract: ELECTRON SPIN RESONANCE STUDY OF SOME COPPER(II) DITHIOCARBAMATES AND THEIR MIXED LIGAND COMPLEXES

AbstractDie ESR‐Spektren der Cu‐dithiocarbamate (I) wurden bei Raumtemp. und bei 1 13 K in CHC13/EtOH‐Mischungen aufgenommen.

Electron spin resonance study of some copper(II) dithiocarbamates and their mixed-ligand complexes

The e.s.r. spectra of seven copper(II) dithiocarbamates have been recorded in chloroform–ethanol mixtures at room temperature and at 113 K. It has been found that the addition of a range of salts to these dithiocarbamates destroys the complex forming a mixed-ligand complex, [Cu(S2CNR2)X], with a new e.s.r. spectrum. When X is Cl or Br the additional interaction of the unpaired electron with a single halogen nucleus is observed. The [Cu(S2CNEt2)Cl] complex forms a dipole–dipole coupled dimer and a computer simulation of the ΔMs= 2 absorption of this dimer has been obtained.

Magnetic susceptibility and magnetic anisotropy studies in some ferric dithiocarbamates exhibiting spin-crossover phenomena

The average magnetic susceptibility and magnetic anisotropy between 77 and 300 K on three ferric dithiocarbamates, Fe[RR’(dtc)13 (R, R’ = ethyl, n-butyl, and pyrrolidyl), crystallized from benzene have been reported. The systems exhibit spin crossover between two spin states, S = and 5/2. The average susceptibility measurements, on samples crystallized from benzene or chloroform-ethanol mixture, show a strong dependence on temperature and on the solvent molecules in the lattice. The effect is most significant in the n-butyl and pyrrolidyl derivatives. Magnetic anisotropy measurements show the existence of considerable rhombic distortion in the systems, contrary to the axial symmetry deduced from x-ray structural investigations. The experimental data have been analyzed by making appropriate modifications in the theory based on thermal equilibrium between 2Tz and 6A1 terms. The effects of trigonal distortion, namely (1) the splitting of ’T2 due to trigonal distortion (6J, (2) zero-field splitting of 6A1 (D), and (3) mixing of two sets of “e” orbitals ( q ) , were considered. The ratio of vibronic partition functions for the 6Al and ’T2 terms was introduced in the form of a parameter C. The parameter C was found essential for fitting the average susceptibility data. The various ligand field parameters such as the separation of 2Tz 6A1 (&), al, D, C, and q have been estimated. The average susceptibility data are rather insensitive to the sign of the a1 and it is shown that the magnetic anisotropy data provide a means of estimating the sign and magnitude of 6,. 61 was found to be negative in all the three derivatives crystallized from benzene. This is contrary to the earlier studies, where the average magnetic susceptibilities were fitted with positive values of hl.

Determination of ferrous ion in microsamples of hexagonal ferrites

A sensitive and accurate method is described for determining microgram amounts of ferrous iron associated with a large excess of ferric iron and various bivalent cations, in hexagonal ferrites. Ferrous iron is complexed with bathophenanthroline, extracted into a chloroform-ethanol mixture and spectrophotometrically measured at 540 nm against a 1∶3 v/v chloroform-ethanol mixture. Ferric iron is masked with ammonium dihydrogen phosphate. The analytical conditions are stated for determination of iron(II) in both solvents used for ferrites, viz., hydrochloric and phosphoric acids. Cobalt, copper, and nickel do not interfere if the procedures suggested are used. Ferrous iron down to 0.02% can be determined in samples weighing only a few milligrams.

A thin-layer chromatographic method for the determination of capsaicin in ground paprika.

A method has been developed for the analysis of samples containing capsaicin in amounts above and below 10 mg per 100 g. The same thin-layer procedure is used for all samples, but preliminary extraction varies according to the level of capsaicin in the sample.For levels above 10 mg per 100 g, the sample is extracted with diethyl ether; for lower levels, the ether is removed by distillation, the residue dissolved in ethanol and the solution shaken with light petroleum to remove colouring matter. The ethanolic solution containing the capsaicin is evaporated to dryness and the residue extracted with ether.The extract is transferred on to a Kieselgel G layer and developed with a chloroform-ethanol mixture. The capsaicin is made visible with iron(III) chloride-potassium ferricyanide reagent.

The Tissue Distribution of Tritiated Digoxin in Human Subjects.

s1 May 1966The Tissue Distribution of Tritiated Digoxin in Human Subjects.James E. Doherty, M.D., F.A.C.P., William H. Perkins, M.D., F.A.C.P.James E. Doherty, M.D., F.A.C.P.Search for more papers by this author, William H. Perkins, M.D., F.A.C.P.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-64-5-1158_2 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail ExcerptTen patients given tritium-labeled digoxin for congestive heart failure subsequently died from 3½ hours to 6 weeks after receiving the medication. Postmortem examination was done and samples of heart, liver, kidney, adrenals, thyroid, lung, brain, pancreas, spleen, skeletal muscle, and diaphragm were obtained. The tissues were homogenized, lyophilized, and extracted with chloroform. The extract was passed through an alumina column and eluted with a chloroform-ethanol mixture. This method will recover 96% of digoxin, its metabolites or both. The highest concentration of digoxin per gram of wet tissue was present in heart muscle in patients with an elevated blood urea nitrogen... This content is PDF only. To continue reading please click on the PDF icon. Author, Article, and Disclosure InformationAffiliations: Little Rock, Arkansas PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics 1 May 1966Volume 64, Issue 5Page: 1158-1158KeywordsKidneysLiverLungsMetabolitesMyocardiumPancreasSkeletal musclesSpleenThyroidTissue distribution Issue Published: 1 May 1966 PDF DownloadLoading ...

クロマトグラフィーによるマオウ・アルカロイドの分離定量 (第1報)

Separatory determination of Ephedra alkaloids has not been established as yet. By the application of partition column chromatography or adsorption chromatography, Separatory determination of l-methylephedrine from l-ephedrine or d-pseudoephedrine was successfully carried out. In the case of partition chromatography, Celite 545 was used as the carrier, buffer solution of pH 6.4 as the stationary phase, and chloroform as the moving phase to separate l-methylephedrine from the sample of alkaloid mixture. The use of chloroform-ethanol mixture (5:1 by volume) as the moving phase then separated l-ephedrine or d-pseudoephedrine. In adsorption chromatography, Brockmann's alumina was used as the adsorbent and the mixture sample was developed with 85% butanol-ether mixture (1:50 by volume) to separate l-methyl-ephedrine. Development with 85% ethanol-ether mixture (1:1 by volume) eluted the remaining l-ephedrine or d-pseudoephedrine. Each of the alkaloids separated by chromatography was determined by nonaqueous or neutralization titration.

Additions and Corrections - Vapor-Liquid Equilibrium. II. Chloroform-Ethanol Mixtures at 35, 45, and 55 degrees

Additions and Corrections - Vapor-Liquid Equilibrium. II. Chloroform-Ethanol Mixtures at 35, 45, and 55 degrees