Search results for "Hydrogen chloride"
showing 10 items of 13 documents
Low-lying Rydberg states of HCl.
2008
Vertical excitation energies belonging to some different Rydberg series of hydrogen chloride have been determined with a coupled-cluster theoretical approach. These excitation energies have allowed us to calculate electric dipole transition intensities in HCl and allow additional assessment of the calculation approach presently used to provide an adequate description of the valence and Rydberg states of HCl. The molecular quantum defect orbital has been applied to the calculation of oscillator strengths. In particular, new insight is given on the assignment of states as the R1Pi, the 1Delta(4dpi and 5ppi), the 1Sigma+(4dpi), and the nddelta(1Pi, 1Phi) and 4f states.
ChemInform Abstract: Attempted Preparation of Trisphenol-II.
2010
Abstract Condensation of 4,4-bis-(4-methoxyphenyl)-2-methyl-2-pentanol with phenol, in the presence of hydrogen chloride, gives 1,3,3-trimethyl-1-(4-methoxyphenyl)-5-methoxyindan and tris-(4-methoxyphenyl)-ethane instead of expected 2,2,4-tris-(4-methoxyphenyl)-4-methylpentane (trisphenol-II). tris-(4-Hydroxyphenyl)-ethane was obtained, together with bisphenol-A, by condensation of phenol with acetylacetone.
Theoretical Study of the Elimination Kinetics of Carboxylic Acid Derivatives in the Gas Phase. Decomposition of 2-Chloropropionic Acid
1997
The reaction mechanism for the decomposition of 2-chloropropionic acid in the gas phase to form hydrogen chloride, carbon monoxide, and acetaldehyde has been theoretically characterized. Analytical gradients have been used by means of AM1 and PM3 semiempirical procedures and ab initio methods at HF and DFT (BLYP) levels with the 6-31G** basis set. The correlation effects were also included by using the perturbational approach at the MP2 level with the 6-31G** and 6-31++G** basis sets and the variational approach at the CISD/6-31G** level and by means of MCSCF wave functions with a (6,6) complete active space and the 6-31G** basis set. The global potential energy surface has been studied, an…
Influence of small amounts of polyvinylchloride on the recycling of polyethyleneterephthalate
1999
Abstract Polyethylene terephthalate (PET), and polyvinyl chloride (PVC), are commonly encountered in plastics stream coming from separate collections of plastic bottles. The presence of PVC in the recycled PET is very dangerous because of the chain scission provoked by the hydrogen chloride evolved from the macromolecules during degradation of PVC. Recycled PET must be free of PVC; contents of PVC as little as 100 ppm can induce degradation and discoloration of the polyester. PET, in its turn, is degraded when the processing is carried out in the presence of water. In previous work, however, the degradation of PET was eliminated and rather an increase of the molecular weight has been measur…
ChemInform Abstract: Cyclocondensation of 6-Acetyl-4,7-dihydro-5-methyl-7-phenyl[1,2,4]triazolo[1,5-a]pyrimidine with Hydroxylamine and Hydrazine.
2010
The cyclocondensation of 6-acetyl-4,7-dihydro-5-methyl-7-phenyl[1,2,4]triazolo[1,5-a]pyrimidine (3) with hydroxylamine or hydrazine leads to 3a,4,9,9a-tetrahydro-3,9a-dimethyl-4-phenylisoxazolo-[5,4-d][1,2,4]triazolo[1,5-a]pyrimidine (4a) and 3a,4,9,9a-tetrahydro-3,9a-dimethyl-4-phenyl-1H-pyrazolo[3,4-d][1,2,4]triazolo[1,5-a]pyrimidine (4b), respectively. In the presence of methanolic hydrogen chloride, 4b undergoes a cleavage of the pyrimidine ring to yield (5-amino-1,2,4-triazol-1-yl)(3,5-dimethylpyrazol-4-yl)phenylmethane (5). The structure determination of the compounds obtained is based on 1H and 13C nmr spectra including NOE measurements.
Cyclocondensation of 6-acetyl-4,7-dihydro-5-methyl-7-phenyl[1,2,4]triazolo[1,5-a]pyrimidine with hydroxylamine and hydrazine
1998
The cyclocondensation of 6-acetyl-4,7-dihydro-5-methyl-7-phenyl[1,2,4]triazolo[1,5-a]pyrimidine (3) with hydroxylamine or hydrazine leads to 3a,4,9,9a-tetrahydro-3,9a-dimethyl-4-phenylisoxazolo-[5,4-d][1,2,4]triazolo[1,5-a]pyrimidine (4a) and 3a,4,9,9a-tetrahydro-3,9a-dimethyl-4-phenyl-1H-pyrazolo[3,4-d][1,2,4]triazolo[1,5-a]pyrimidine (4b), respectively. In the presence of methanolic hydrogen chloride, 4b undergoes a cleavage of the pyrimidine ring to yield (5-amino-1,2,4-triazol-1-yl)(3,5-dimethylpyrazol-4-yl)phenylmethane (5). The structure determination of the compounds obtained is based on 1H and 13C nmr spectra including NOE measurements.
The tropospheric processing of acidic gases and hydrogen sulphide in volcanic gas plumes as inferred from field and model investigations
2007
Abstract. Improving the constraints on the atmospheric fate and depletion rates of acidic compounds persistently emitted by non-erupting (quiescent) volcanoes is important for quantitatively predicting the environmental impact of volcanic gas plumes. Here, we present new experimental data coupled with modelling studies to investigate the chemical processing of acidic volcanogenic species during tropospheric dispersion. Diffusive tube samplers were deployed at Mount Etna, a very active open-conduit basaltic volcano in eastern Sicily, and Vulcano Island, a closed-conduit quiescent volcano in the Aeolian Islands (northern Sicily). Sulphur dioxide (SO2), hydrogen sulphide (H2S), hydrogen chlori…
Partial Reduction and Selective Transfer of Hydrogen Chloride on Catalytic Gold Nanoparticles
2017
© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim HCl in solution accepts electron density from Au NPs and partially reduces at room temperature, as occurs with other simple diatomic molecules, such as O2 and H2. The activation can be run catalytically in the presence of alkynes to give exclusively E-vinyl chlorides, after the regio- and stereoselective transfer of HCl. Based also on this method, vinyl chloride monomer (VCM) can be produced in a milder and greener way than current industrial processes.
Attempted preparation of trisphenol-II
1998
Abstract Condensation of 4,4-bis-(4-methoxyphenyl)-2-methyl-2-pentanol with phenol, in the presence of hydrogen chloride, gives 1,3,3-trimethyl-1-(4-methoxyphenyl)-5-methoxyindan and tris-(4-methoxyphenyl)-ethane instead of expected 2,2,4-tris-(4-methoxyphenyl)-4-methylpentane (trisphenol-II). tris-(4-Hydroxyphenyl)-ethane was obtained, together with bisphenol-A, by condensation of phenol with acetylacetone.
2,5-Dialkoxysubstituierte Oligo- und Poly(1,4-phenylenethenylen)e
1994
2,5-Dialkoxy Substituted Oligo- and Poly(1,4-phenyleneethenylene)s O-Alkylation and regioselective Rieche formylation of 2-methylhydroquinone (1) yields the 2,5-dialkoxy-4-methylbenzaldehydes 4a–j. The corresponding azomethines 5a–j enter in a strongly alkaline medium a selfcondensation reaction leading to the title compounds 6/7a–j. These conjugated oligomers and polymers possess highly regular structures with exclusively (E)-configurated double bonds. GPC, IR, 1H-, 13C-NMR and MS-FD measurements were used for their characterization. Somewhat different results were obtained for the similarly prepared Schiff base 5l which contains chlorine substituents in the side chains. Cleavage of hydrog…