Solid-state IR-LD spectroscopy of codeine and N-norcodeine derivatives

Linear-dichroic infrared spectra (IR-LD) of 3-ethoxy-4-(N-norcodeino-)cyclobutene-1,2-dione (1) and codeine dihydrogenphosphate (Codeinum phosphoricum) (2), oriented as solid suspensions in nematic liquid crystals, have been measured. IR characteristic band assignments were made, and used in stereo-structural predictions. The results were compared with crystallographic structures of similar organic systems, and found to be in good agreement.     

High-Yield Synthesis of the Novel E,E-2,5-Dimethoxy-1,4-bis[2-(4-ethylcarboxylatestyril)]benzene by the Heck Reaction

The novel E,E-2,5-dimethoxy-1,4-bis[2-(4-ethylcarboxylatestyril)]benzene, 4, was obtained in good yield (92%), by the Heck cross-coupling reaction using Pd(dba)₂ and P(OPh)₃ like catalytic system. The high trans specificity of the product produced by the Heck reaction was confirmed by Fourier Transform–infrared and NMR. The methodology reported can be used as synthetic route for precursors to phenylenevinylene target systems with highly desired functional groups in their molecular structure, such as carboxylic, to build metal–organic frameworks and other applications within the supramolecular chemistry.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

Compound-Independent Calibration by Gas Chromatography-Atomic Emission Detection (GC-AED): Analysis of Molecules with 12 Carbon Atoms

ABSTRACT

This study was designed to demonstrate that Gas Chromatography–Atomic Emission Detection (GC-AED) can be used to set in a Compound-independent calibration (CIC) for quantifying organic compounds with various chemical functions using one reference compound. Experiments were carried out with thirteen organic molecules containing twelve atoms of carbon and different amount of hydrogen, oxygen or sulphur.

The results obtained show that the GC-AED technique allows to quantify a molecule of known chemical structure using the elemental response of C or H and another different molecule as the standard of calibration.     

HYDROXY AND/OR CARBOXY SUBSTITUTED PHOSPHONIC AND BISPHOSPHONIC ACIDS USABLE AS CORROSION AND SCALE INHIBITORS

Abstract

2-Dihydroxyphosphonyl-2-hydroxy-propionic acid (DHHPA), 1,4-bis[(dihydroxyphosphonyl)hydroxy-methyl]benzene (BDHB) and 2,3-bis(dihydroxyphosphonyl)-1,4-butanedioic acid (BDBA) were synthesized by acid catalyzed hydrolysis of the corresponding substituted phosphonates or bisphosphonates. The structure of these compounds was confirmed by elemental analysis as well as by infrared (IR) and proton nuclear magnetic resonance (¹H-NMR) spectroscopy. They can be used as corrosion and scale inhibitors.     

Organic mandelates as promising materials with non-linear optical application

The application of organic salts of mandelic acid (MA) as new materials for optical and non-linear-optical (NLO) application is discussed, using four novel organic salts, i.e. pyridinium-4-aldoxime mandelate (1), 1-aminoisoquinolinium mandelate mandelic acid (2), 2-amino-8-hydroxyquinolinium mandelate (3) and phenylalaninamide mandelate monohydrate (4). The crystal structures, optical and NLO properties are studied by the application of single crystal X-ray diffraction, UV–VIS–NIR spectroscopy, conventional and linear polarized infrared (IR-LD) spectroscopy, thermal methods as well as quantum chemical (ab initio and DFT) calculations.     

Detection of Casting Material on Historical Violins by Infrared Spectroscopy and Total Reflection X-Ray Fluorescence Spectrometry

Abstract

Infrared spectroscopy and total reflection X-ray fluorescence spectrometry are used for the analysis of historical varnishes. Total reflection X-ray fluorescence spectrometry is used in the analysis of the elemental composition; infrared spectroscopy is used to determine the inorganic and organic molecules of the binding media, pigments and additives. On historical violins made by A. Guarneri and L. Widhalm silicon and tin were found by total reflection X-ray fluorescence spectrometry. Silicon was proved to be present in the form of silicon rubber by infrared spectroscopy. A further experiment confirmed that the treatment of a violin with silicon rubber casting material is detectable.     

Use of an Infrared Laser in a Detection System for Liquid Chromatography

Abstract

A liquid chromatography detection system based on an infrared laser has been constructed and some tentative evaluations of its performance have been made. Although restricted to use with a very few solvents (mainly halocarbons), this system should be applicable whenever chloroform or a halocarbon solvent of lower strength (polarity) can be used. Injected sample quantities as small as one microgram have been detected on elution.     

Enantioselective HPLC separation of bioactive C5-chiral 2-pyrazolines on lux amylose-2 and lux cellulose-2: Comparative and mechanistic approaches

Stereoselective analytical HPLC separations have been developed for a series of biologically active chiral 2-pyrazolines (1-22) to be used in monitoring their resolution reactions or to custom semipreparative HPLC separations prior to biological assessment of both enantiomers. Polysaccharide-based chiral stationary phases (CSPs), namely, Lux amylose-2 and cellulose-2, have been used. Both normal (n-hexane/ethanol) and polar organic (ethanol, methanol, acetonitrile, or mixtures thereof) elution modes were very beneficial for the achievement of baseline separations. The impact of various chemical moieties embedded in the structures of 2-pyrazolines 1-22 and the adopted stationary phases on chiral recognition has been investigated. A case of reversed order of elution following alterations in either stationary phase or elution mode has been observed. Our findings recommend that normal elution mode can be used for optimizing semipreparative HPLC methods whereas polar organic mobile phases (such as acetonitrile and ethanol) are more suited to stereoselective reactions monitoring, routine quality control work, or for pharmacological and toxicological assays. These results settle the implementation of polysaccharide-based CSPs using different elution modes and declare the practicality of such CSPs in stereoselective HPLC.     

Molecular recognition of organic guest vapor by solid adamantylcalix[4]arene

A series of inclusion compounds prepared by saturation of the solid adamantyl[4]calixarene (host 1) with vaporous organic guests at 298 K was studied by thermal gravimetry and static headspace GC analyses. The sorption isotherms of guests by host 1, the stoichiometry of the guest—host inclusion compounds, and the Gibbs energies of their formation were determined. The data obtained give evidence of the molecular recognition of the guest shape by host 1. Hence, compound 1 can be used in sensors for recognizing volatile organic compounds with no strong hydrogen or donor-acceptor bonds involved.     

Synthesis and structure of a new polyoxometalate-based inorganic–organic hybrid and application as a chemically bulk-modified electrode

A new Keggin-type polyoxometalate-based inorganic–organic hybrid, [Cu(H₂O)₂(daphen)]₂[SiW₁₂O₄₀]·9H₂O (1) (daphen?=?5,6-diamino-1,10-phenanthroline), was hydrothermally synthesized, and characterized by single-crystal X-ray diffraction, elemental analysis, infrared spectroscopy, fluorescence spectra, and thermal analysis. Single-crystal X-ray diffraction analysis reveals that in 1, [SiW₁₂O₄₀]^4? is a tetradentate ligand with its four terminal oxygens coordinating to four Cu(II)–daphen fragments to form a 2D sheet with (4,4) topology. On the basis of the insolubility of 1 in water and common organic solvent and its reversible multielectron redox processes, 1 was used to fabricate a bulk-modified carbon paste electrode (1-CPE) by direct mixing. Electrochemistry indicated that 1-CPE is stable over hundreds of cycles and possessed electrocatalytic activity toward the reduction reactions of nitrite.     

A pillar-layered Cd(II) metal-organic framework for selective detection of organic explosives

The detection of explosives is crucial for homeland security, environmental cleaning, and military issues. As a new class of porous materials, metal-organic frameworks (MOFs) are promising platforms for the detection of organic explosives. In this work, a new pillar-layered Cd(II) MOF, [CdL_0.5dpe_0.5]·2H₂O (BUT-202, H₄L = 4,8-disulfonaphthalene-2,6-dicarboxylic acid, dpe = 1,2-bis(4-pyridyl)ethylene), was synthesized and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis, infrared spectroscopy, and elemental analysis. BUT-202 has good fluorescent properties, which can be selectively quenched by trace amounts of 2,4,6-trinitrophenol (TNP) in DMF with low detection limit of 0.2 μM.     

The Determination of Total C-H by Near Infrared Analysis

Abstract

A method for determining total hydrogen bonded to carbon has been developed, employing the 1st overtone of the C-H stretch which occurs in the near infrared spectral region. Six different hydrocarbons have been employed; all gave satisfactory results. Mixtures can be studied with an accuracy of approximately 10%. The method should find application in the study of pollution by organic materials.     

Fire impact on forest soils evaluated using near-infrared spectroscopy and multivariate calibration

The assessment of physico-chemical properties in forest soils affected by fires was evaluated using near infrared reflectance (NIR) spectroscopy coupled with chemometric methods. In order to describe the soil properties, measurements were taken of the total organic carbon on solid phase, the total nitrogen content, the organic carbon and the specific absorbences at 254 and 280 nm of humic substances, organic carbon in humic and fulvic acids, concentrations of NH₄⁺, Ca²⁺, Mg²⁺, K⁺ and phosphorus in addition to NIR spectra. Then, a fire recurrence index was defined and calculated according to the different fires extents affecting soils. This calculation includes the occurrence of fires as well as the time elapsed since the last fire. This study shows that NIR spectroscopy could be considered as a tool for soil monitoring, particularly for the quantitative prediction of the total organic carbon, total nitrogen content, organic carbon in humic substances, concentrations of phosphorus, Mg²⁺, Ca²⁺ and NH₄⁺ and humic substances UVSA₂₅₄. Further validation in this field is necessary however, to try and make successful predictions of K⁺, organic carbon in humic and fulvic acids and the humic substances UVSA₂₈₀. Moreover, NIR coupled with PLS can also be useful to predict the fire recurrence index in order to determine the spatial variability. Also this method can be used to map more or less burned areas and possibly to apply adequate rehabilitation techniques, like soil litter reconstitution with organic enrichments (industrial composts) or reforestation. Finally, the proposed recurrence index can be considered representative of the state of the soils.     

Comparison of Two Novel Techniques for Eliminating Liquid Chromatography Gradient Ghost Peaks

Abstract

Distilled water to organic gradients in reversed phase liquid chromatography are often plagued with UV-detectable “ghost” peaks that can obscure sample peaks and complicate interpretation of results.^3,4 These contaminants usually come from the distilled water³ although it is possible for them to originate in the organic eluent⁴. The ghost-peak problem can be eliminated by using specially prepared “LC-grade” water, although this is expensive. In addition water can be cleaned with the Milli-Q ion-exchange system, containing a carbon absorption column⁵ but not where these systems contain buffers or organic amine eluting agents such as triethylamine phosphate. Gurkin and Ripphahn have shown that a C-8 silica column can be used off-line in a low- pressure mode to clean water⁶.     

Novel sulfonated hydrophilic indium(III) and gallium(III) phthalocyanine photosensitizers: preparation and investigation of photophysicochemical properties

The new tetra-non-peripherally benzenesulfonic acid-substituted hydrophilic gallium chloride and indium chloride phthalocyanine complexes have been synthesized by cyclotetramerization of 4-(2,3-dicyanophenyl)benzenesulfonic acid (1). The newly synthesized phthalocyanines have been characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, mass and UV–vis spectroscopy techniques. The water-soluble gallium(III) phthalocyanine derivative (2) was aggregated in aqueous media but was fully disaggregated in the presence of a surfactant Triton X-100. The incorporation of sulfonate moieties of the phthalocyanine macrocycle provides hydrophilic character to the new compounds, which is useful for drug administration and serves as crucial in PDT application. So, the photochemical properties (singlet oxygen quantum yields and photodegradation quantum yields) and photophysical properties (fluorescence behavior) of the complexes were reported in different solutions (DMSO and water). The results of spectral measurements showed that both np-GaPc (2) and np-InPc (3) can be used as sensitizers in PDT because of their singlet oxygen efficiencies.     

Statistical Model for Organic Chromatographic Trace Analysis of Complex Samples. A Case Study: Plant Extracts

Abstract

The use of pooled plant extracts is described in the estimation of matrix interference in HPLC (UV and EC) determinations of organic compounds in plant extracts. An extract from freeze dried leaves of 134 different plant species was used for this purpose. It was split in different subgroups with solid extraction clean-up procedures. UV, EC and chromatographic data of the subgroups were used in the calculation of minimum concentrations of organic compounds which are still accurately determinable in plant samples with HPLC methods. The UV and/or EC characteristics of the compound must be known. The contribution of the solid phase extraction procedures and of the analytical system to the selectivity of the method can be estimated. Information is also supplied which allows rapid comparison of the selectivity of the UV and EC (single, or dual parallel) detectors for the determination of a specified compound.     

Cellulosic-based hydrogel from biomass material for removal of metals from waste water

Abstract

Cellulose and carboxymethyl cellulose (CMC), prepared from rice straw, were used for hydrogel preparation, separately or in a mixture of both of them in a ratios of 1:1, 1:4, 1:9, 2:3 and 3:7 (by weight).They were polymerized with partially neutralized acrylic acid (AA) in the presence of potassium persulphate, as initiator, and vinylsulphone (VS), as cross-linker. Moreover, glutaraldehyde, N,N-methylene bis acrylamide (MBA) and Epichlorohydrin (ECH) were used as cross-linker for the mixture of 1:1 of Cellulose: CMC. The mechanism of the polymerization was studied and the resulted hydrogels were characterized for their appearances, yields percentage, and water absorbencies. The Fourier transform infrared spectroscopy (FT-IR) and XRD analysis were also investigated for the hydrogel samples. Since the textile industry produces large volumes of wastewaters which contain hazardous compounds such as dyes, heavy metals like Cu(II), and surfactants, so we aimed in this research to use the hydrogel samples for Cu²⁺ absorption that can be presented in the wastewater. The FT-IR spectrum, before and after absorption, indicated that the prepared hydrogels were able to absorb the Cu²⁺. The Cu²⁺ ions can be recovered and dried to be reused again as well as the hydrogel samples can be available again for reuse.     

Effect of Phosphorus Amount on the Particle Size and Catalytic Performance of Heterogeneous Nickel(II) Schiff-Base Complex in Aldol Condensation Reaction

Abstract

The organic–inorganic hybrid of citric acid, tetraethoxysilane (TEOS), and triethylphosphate (TEP) doped by a nickel Schiff-base complex was prepared by sol–gel method. The prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmittance electron microscopy (TEM), scanning tunnelling microscopy (STM), and infrared spectroscopy (IR). In order to determine the phosphorus amount effect on the catalytic activity of the prepared composites, the aldol condensation was used as a model reaction. The results revealed that the composite with 10% phosphorus is a better catalyst in comparison with other composites.

[Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the following free supplemental files: Additional figures file.]     

Infrared Examination of Gas Chromatography Effluent using a Dual Beam,Single Detector Interference Spectrometer

Abstract

An infrared interference spectrometer set to operate in a dual beam, optical nulling mode can be used with a single detector. The use of such instrumentation for the examination of gas chromatography effluent was explored, and found promising.     

Cu(II)-triggered release of paclitaxel from a supramolecular complex

The research on the stimuli-responsive property of biological or synthetic macromolecules in a wide range of scientific fields is a crucial subject for the achievements of the targeted drug release and the precise control of the functions of the supramolecules at a molecular level. We used an anthraquinone-functioned cyclodextrin (1) bridged by an aza-arm to solubilise paclitaxel (PTX) by forming a supramolecular complex (1/PTX). The possible inclusion mode was given based on the experimental results of ultraviolet–visible spectroscopy, Fourier transform infrared, X-ray diffraction, fluorescence spectra, nuclear magnetic resonance, transmission electron microscope, scanning electron microscope and dynamic light scattering characterisations. The controlled release of PTX can be achieved by adding Cu²⁺ to the solution. This study provides useful references in developing stimuli-responsive drug-carrying and drug-releasing materials.