Carbon Disulphide Solution Research Articles

Wet flue gas desulphurization using a new O-element design

Scrubbing by liquid sprayingis one of the most effective processes used for removal of fine particles and soluble gas pollutants (such as SO2, HCl, HF) from the flue gas. The primary function of venturi scrubber, which represents the first stage of the wet flue gas cleaning processes, such as in waste incineration plants, is to capture fine particles as well as remove HCl, HF or SO2 as a result of the decrease in the flue gas temperature before entering the absorption column. In this paper, a newly developed four-branch O-element is proposed as a replacement for venturi scrubber. By means of this device, sulphur dioxide (SO2) removal efficiency and pressure loss and temperature drop were experimentally calculated. The dependence of these variables on liquid–gas ratio was monitored. The simulated flue gas was prepared by the combustion of the carbon disulphide solution in toluene (1:1 vol.) in the presence of the flame in the reactor. Such prepared flue gas with temperature around 150 °C was processed in the laboratory-designed O-element scrubber. Water was used as an absorbent liquid. The maximal efficiency of SO2 removal achieved by this process was up to 70 %, which is far better in comparison with the commonly used venturi scrubbers. The pressure drop of our proposed newly designed wet scrubber is similar to that of the commonly used venturi scrubbers; nevertheless, the influence of the amount of the liquid on pressure drop is not so significant. In parallel, a mathematical model describing the mass transfer, enthalpy balance and pH change of the absorbing solution was also developed. Enthalpy balance was calculated by numerical iteration to determine the unknown outlet liquid temperature. Mass transfer calculation was used for the determination of complete Henry constant from all the subsequent SO2 absorption reactions.

Investigation of Fullerene Solutions by the Molecular Dynamics Method

Simulation of aqueous and carbon disulphide solutions of fullerene C60 was performed by molecular dynamics (MD). We proposed the correlation of fullerene solubility versus the mean force potential, ΔFC60–C60(r), obtained from the numeric experiment.

Conformational behaviour of trimethyl phosphate studied by infrared spectroscopy

The conformational behaviour of trimethyl phosphate was studied by infrared spectroscopy in the liquid phase and as 1% solutions in a wide range of solvents. Variable temperature studies carried out in carbon disulphide and liquid xenon solutions, and in the pure liquid phase, showed a reversal in the relative stability of the two conformers between liquid xenon and carbon disulphide solutions. In liquid xenon solution the less polar conformer II is ≈ 1.8 kJ mol −1 lower in energy, whereas in CS 2 solution the more polar conformer I is ≈ 1.4 kJ mol −1 more stable. In the pure liquid, the energy difference between the two conformers is similar to that in carbon disulphide solution. Ab initio calculations predict that conformer II has C 3 symmetry with all the methoxy groups in the gauche configuration, whereas conformer I has C 1 symmetry with one trans and two gauche methoxy groups.

Reactivity of Aluminium(III) Iodide Towards Some Esters and Ethers. Evidence of O-C Bond Cleavage Induced by Chelation

Abstract The reactions of aluminium(III) iodide with a number of common potentially chelating ethers and esters have been studied in diethylether or carbon disulphide solutions. Cleavage of the O-C bond occurred under very mild conditions. Differences in reactivity of aluminium iodide towards some closely related compounds suggest chelation is important in the mechanism of cleavage.

The C60-Catalysed Oxidation of Hydrogen Sulphide to Sulphur

Abstract Carbon disulphide is rapidly converted into sulphur by C60 deposited on neutral alumina, through formation of hydrogen sulphide which is then oxidised. C60 is more effective than graphite in this oxidation, which also occurs (though more slowly) in the absence of alumina. It is therefore essential to remove all traces of carbon disulphide traces when purifying C60 by column chromatography of soot extract deposited from carbon disulphide solutions.

Vibrational spectra and conformations of 1, 4‐dibromobut‐2‐yne and 1,4‐diiodobut‐2‐yne

AbstractThe Raman spectra of 1,4‐dibromobut‐2‐yne (BrBr) as a liquid at various temperatures and as an amorphous and crystalline solid at low temperatures were recorded in the 3200‐10 cm−1 region. IR spectra of the liquid at room temperature and of the amorphous and crystalline solids at low temperatures (4000‐50 cm−1) were obtained. Additional IR spectra of the vapour were recorded (4000‐500 cm−1). The spectra of the liquid phase showed characteristic, broad bands below 500 cm−1. No temperature dependence was detected in these, and the spectra of the amorphous solid at 90 K are almost identical with the room temperature spectra of the liquid. A shoulder on the Rayleigh line was observed at ca. 20 cm−1 in the Raman spectrum of the amorphous BrBr at 90 K which tentatively, has been interpreted as the torsional mode. In the crystal an anti conformer was present, while the spectra of the vapour and the liquid were interpreted in terms of large torsional freedom. The Raman and IR spectra of the very unstable 1,4‐diiodobut‐2‐yne (II) as a crystalline solid were recorded in the 4000‐20 cm−1 range at low temperatures. Spectra of carbon disulphide solutions at temperatures 250–260 K were obtained and additional IR spectra of II in Nujol mulls and in KBr pellets were also recorded. In the region below 500 cm−1, Where other 1,4‐dihalobut‐2‐ynes have characteristic, broad bands, a high irregular background was observed in the Raman spectrum of II in solution. The spectra agree with an anti conformer present in the crystal and nearly free internal rotation in the liquid. The vibrational assignments are supported by force constant calculations and by a correlation diagram for the vibrations of the six skeletal bending modes in 1,4‐dichlorobut‐2‐yne, BrBr and II.

ESR studies of radical cations produced on doping discotic liquid crystals with Lewis acids

Abstract We have shown previously that doping the Dhd phase of 2,3,6,7,10,11-hexahexyloxytriphenylene (HAT6) with 1–5 mole per cent of a Lewis acid converts it from an insulator to a p-type semiconductor. Herein, ESR spectroscopic studies establish that this and related oxidation reactions produce radical cations, but that these radical cations can be of several types. For instance, oxidation of the parent hydrocarbon triphenylene (TP) with aluminium trichloride in carbon disulphide solution gives a non-covalently bonded dimer (TP)2 + in which the charge is delocalized over two aromatic nuclei. Oxidation of HAT6 in solution gives either charged aggregates (HAT6). n + or the monomeric radical cation (HAT6). +. Formation of (TP).2+, (HAT6). n +, or (HAT6).+ involves removal of an electron from a π-orbital. An alternative reaction is revealed by studies of 2,3,6,7,10,11-hexahexyl-thiotriphenylene (HTT6): removal of an electron from a [sgrave]-orbital. In this case a cation with a novel two-centre, three-electron, sulphur-sulphur bond is formed. Electronic conduction in doped neat HAT6 involves a mechanism in which the charge carrier hops between localized states. These localized states may be discrete (HAT6).+ ions but are more probably (HAT6). n + aggregates or polarons.

Radial distribution function analyses of polythiohydroquinone

In recent years, the RDF analysis [1-4] of X-ray diffraction patterns has become a powerful tool for studying the structures of non-crystalline disordered materials. This technique may be applied to systems for which the average radial distribution function is spherically symmetrical, such as pure liquids, solutions, glasses and finely divided powders. It yields information not only about structural parameters but also many physical parameters such as Debye temperature, coupling coefficients, coordination numbers and interatomic potentials. The polymer, polythiohydroquinone, reported here does not crystallize and therefore single crystal techniques cannot be used to obtain structural information. Hydroquinone and excess sulphur were mixed thoroughly and poured into a glass tube. The tube was flushed several times with nitrogen and placed in a furnace in a nearly horizontal position. The issuing hydrogen sulphide gas was trapped in a lead acetate solution. After several hours the tube was removed and allowed to cool. The material was washed with concentrated sulphuric acid, followed by concentrated alkali solution to remove low molecular weight products and finally with hot carbon disulphide solutions to remove excess sulphur. The yield was about 70%. X-ray diffraction patterns for the present sample were recorded with the help of a Phillips diffractometer on a strip chart, the scanning rate being 2 ° min -1 , using MoK~ radiation in the range s = 0.77 to s = 8.96 (where s = 4re sin 0/4). The background radiation was suppressed with the aid of a discriminator by running the diffractometer once without sample. Then the sample was mounted and the intensities recorded. Other corrections for polarization and absorption were carried out using procedures described by Kaelble [2]. Tubulated values of atomic scattering factors [5] and incoherent scattering factors [6] were used for obtaining independent scattering curves. The corrected intensities were scaled to electron units by the method described by Kroughmoe [7]. The contribution of the flat-faced diffractometer sample in the small-angle region and that due to multiple scattering were subtracted following the method described by Warren [8]. Following the procedure described by Kaelble, the radial distribution function for polyatomic samples, 47t?2~0(r) is given by

Indirect band gap investigation of orthorhombic single crystals of sulfur

Single crystals of pure and selenium doped orthorhombic sulfur crystal were prepared from carbon disulphide solution. They were investigated at two temperatures (6°C and 85°C) in an optical absorption apparatus. The optical absorption increased with temperature and it was found to be higher for Se doped crystals within the same range of temperatures. The indirect allowed band gap transitions and assisting phonons were observed. Their values were found to shift toward lower energy with increasing temperatures. They are also lower for doped samples. At 6°C, the indirect allowed band gaps are 2.61 eV and 2.56 eV for pure and selenium-doped crystals, respectively. At 85°C, they are 2.44 eV and 2.40 eV for pure and doped crystals, respectively. The phonons associated with the optical transitions could be attributed to the stretching band of S 8 rings.

Molecular properties of acetone in carbon disulphide solution (1:124)

Some results for the acetone molecule diluted in carbon disulphide liquid have been obtained using a model, previously developed by us, which links Quantum Chemistry and Statistical Mechanics. The atom-atom radial distribution functions used to carry out the calculations has been evaluated whit the Monte-Carlo method. An analytical i n termolecular potential directly obtained from the Perturbation The o ry, has been employed in the Simulation.

Vibrational spectra and structure of chlorine substituted cyclopropanes: Part I. cis-1,2,3-Trichlorocyclopropane

The synthesis of cis-1,2,3-trichlorocyclopropane is reported. The infrared spectra have been recorded between 4000 and 400 cm−1 in the polycrystalline solid phase, and between 4000 and 200 cm−1 in the gas phase. The spectrum of a solution in carbon disulphide was measured from 1400 to 400 cm−1. The Raman spectrum has been obtained between 4000 and 100 cm−1 in the solid phase. An assignment of the fundamentals of the title compound is proposed and compared with similar molecules. The spectrum unequivocally proves the CJV structure of the molecule.

Flame ionization detector response to coeluting hydrocarbons and carbon disulphide and its application to the determination of the sum of C6-C11 alkanes and cycloalkanes in air

The flame ionisation detector response to C6-C11 aliphatic hydrocarbon solutions in carbon disulphide in the concentration range between 1.3-9.5 mg ml-1 retained lineary despite the excess of solvent entering the detector simultaneously with the analyte. Pure carbon disulphide exhibited a small positive detector response which did not interfere in calibration procedure and which, under certain GC conditions, inverted to negative values. This response was not proportional to the injected volume and was strongly influenced by the column temperature and/or bleed. On the basis of these findings, a method compatible with the widely used charcoal tube carbon disulphide desorption procedure was developed and evaluated. It consists of static desorption of the sum of aliphatic alkanes and cycloalkanes from the activated charcoal after which an internal standard is added to the supernatant eluate. The resulting carbon disulphide solution is analysed on a highly polar stationary phase 1,2,3-tris(2-cyanoethoxy)propane where the solvent and the analyte coelute in a single peak, the height of which is practically proportional to the sum of alkanes and cycloalkanes present. This also makes determinations of other substances present in the sample more simple. The field test of the proposed method yielded values comparable in precision and accuracy with a control infrared spectrophotometric method.

Helical dislocations in α-sulphur single crystals

Abstract Dislocation helices have been observed in crystals of sulphur grown from solution in carbon disulphide at temperatures close to ambient temperature. Their formation is discussed in terms of the low lattice and high dislocation core diffusion in this solid.

Far infrared and microwave spectral studies on the molecular dynamics and interactions of methyl iodide in carbon disulphide solution

The far-infrared and microwave spectra of methyl iodide in dilute solution (0.1 mf) in carbon disulphide have been used to measure the relaxation times and correlation function for dipole reorientation in this particular medium. It is shown that rotation is faster than in the liquid phase due to removal of intermolecular correlations. The short time part of the correlation function is shown to be distinctly non-exponential and this part of the power spectrum is fitted to a model which enables the intermolecular mean square torque to be determined. The spectral second moment agrees well with that calculated using the classical rotational energy indicating that induced dipole absorption is not of major importance in this solution.

High resolution 1H NMR spectra of 2,2′‐biquinoline

AbstractFrom analysis and refinement by the LAOCOON III program of the 220 MHz 1H spectrum of 2,2′‐biquinoline, recorded as a saturated solution in carbon disulphide, most derived chemical shifts and coupling constants are close to corresponding values in quinoline. However, H‐3 is at 1.5 ppm lower field in 2,2′‐biquinoline than in quinoline and the ortho‐coupling 3J(34) in the heterocyclic ring is 0.5 Hz larger in 2,2′‐biquinoline than in quinoline; fairly free rotation about the 2,2′ bond is inferred.

1H and 13C NMR chemical shifts of methyl-substituted benz[ a]anthracenes

High-resolution 1H NMR spectra are described for 1-, 2-, 3-, 4-, 5-, 6-, 8-, 11-, and 12-methyl-and 1,12-, 3,9-, and 3,10-dimethylbenz[ a]anthracenes recorded at 220 MHz in carbon disulphide solution. 1H shifts reflect ortho and para substituent effects as well as molecular distortions, especially in the bay regions of the 1-, 12-, and 1,12- compounds. 13C NMR resonances are reported for 4-,5-, and 12-methyl-, and 1,12-, 3,9-, and 3,10-dimethylbenz[ a]lanthracenes. The protonated aromatic 13C shifts show γ- and δ-steric effects; γ shieldings also cause higher field (20 ppm) CH 3-resonances in 4- and 5-methylbenz[ a]anthracenes than for unhindered methyl groups (∼ 21.6 ppm) in 3,9- and 3,10-dimethylbenz[ a]anthracenes.

Influence of chemical exchange on the temperature dependence of Eu(fod)3‐induced shifts

AbstractTemperature dependences of the paramagnetic shifts induced by Eu(fod)3 in 1H NMR spectra of ethylene oxide in carbon disulphide solution are obtained in the temperature range from +40 to − 100°C at 100 MHz and from +30 to −60°C at 60 MHz. The influence of chemical exchange leads to a decrease of the observed paramagnetic shifts with decreasing temperature. It is shown that a modified Swift and Connick equation can be used to describe the observed dependences. Upper limits of the mean lifetimes of the Eu(fod)3‐ethylene oxide adduct are τp < 1·7 × 10−8 s at 14 °C and τp < 1 × 10−8 s at 20 °C, respectively. The corresponding activation energy is equal to Va = 13·7 kcal/mol.

ChemInform Abstract: VIBRATIONAL ASSIGNMENT, INFRARED ABSORPTION INTENSITIES, GAUCHE DIHEDRAL ANGLE AND ENERGY DIFFERENCE BETWEEN ROTATIONAL ISOMERS OF CHLOROACETONE

Abstract Infrared absorption intensities of fundamental bands of chloroacetone CH3COCH2Cl have been measured in carbon disulphide solution, and intensity data have been analysed to determine the energy difference between the rotational isomers by applying the absolute intensity method. The value determined for the energy difference is in good agreement with that obtained by the temperature variation method. Further, in order to determine the dihedral angle of the gauche isomer, normal frequencies and absolute band intensities have been computed for various rotational angles and compared with observed values. As a result, the gauche dihedral angle has been determined as 150° ± 10°, which is in good agreement with that obtained by previous authors.

Vibrational assignment, infrared absorption intensities, gauche dihedral angle and energy difference between rotational isomers of chloroacetone

Infrared absorption intensities of fundamental bands of chloroacetone CH 3COCH 2Cl have been measured in carbon disulphide solution, and intensity data have been analysed to determine the energy difference between the rotational isomers by applying the absolute intensity method. The value determined for the energy difference is in good agreement with that obtained by the temperature variation method. Further, in order to determine the dihedral angle of the gauche isomer, normal frequencies and absolute band intensities have been computed for various rotational angles and compared with observed values. As a result, the gauche dihedral angle has been determined as 150° ± 10°, which is in good agreement with that obtained by previous authors.

Dislocations in α-sulphur

Abstract A study has been made of the solvent etching of naturally-occurring (001), (011), {111} and {113} faces and prepared (110) faces of orthorhombic sulphur crystals grown from solution in carbon disulphide. No pitting was observed on the (011) and {113} faces. Etching of the remaining faces revealed crystallographically-shaped pits, the shapes and distributions of which were consistent with their formation at the emergent ends of dislocations in the lattice. The probable geometry of the dislocations is discussed. Deformation by point indentation indicated that slip occurs predominantly on {111} glide planes. An X-ray topographic study is also reported, which complements the above results. Direct evidence is presented on the geometry of the active slip systems and on the mobility of individual dislocations. Of the observed slip systems it is shown that only (11) [110], (11) [110], (111) [110], (11) [10] are facile; {111} 〈10〉 or 〈01〉 and (001) [100] or 〈10〉 are much more difficult to activate. The ex...