The microwave spectrum and structure of trifluoro-ethylene

The microwave spectrum of trifluoroethylene F₂C=CHF is reported, and a number of ground state and vibrationally excited state lines are assigned. The ground state rotational constants are: 10665.31, 3872.36, 2837.97 MHz. The dipole components are μ_a = 0.075 D, μ_b = 1.30 D, and μ_total = 1.30 D. Calculations of the inertia defect of the ground and excited states indicate that the equilibrium configuration is planar.     

The microwave spectrum and electronic structure of cyanogen azide

The rotational spectrum of cyanogen azide has been assigned and yields values of A = 38.06737 GHz, B = 3.18517 GHz and C = 2.93357 GHz. The measured dipole moment components of μ_a = 2.96 D, μ_b = 0.44 D. μ_total = 2.99 D are compared with those computed using a CNDO/2 approach for NCN₃ and several related molecules.     

The microwave spectrum,chlorine nuclear quadrupole resonance spectrum and structure of propiolyl chloride

The microwave rotational spectra of the two most abundant isotopic species of propiolyl chloride have yielded rotational constants and nuclear quadrupole coupling constants. These, in combination with the chloride nuclear quadrupole resonance spectra, have yielded the molecular structure.     

The microwave spectrum,structure and dipole moment of 1,4-pentadiyne

The microwave spectra of 1,4-pentadiyne and 1,4-pentadiyne-1,5-d₂ are assigned and rotational and centrifugal distortion constants obtained. A unique structure could not be determined. However, analysis of the moments of inertia indicates that the bond distances in C₅H₄ are close to typical values found in other related compounds. An interaction involving the acetylene moieties is evidenced by the derived bond angles. The data are consistent with either the central CCC angle being close to the tetrahedral value with the acetylene groups pushed away from linearity by approximately 3–4° or opening of the central CCC angle to about 113° along with linear acetylene groups. A range of structures between these two is also possible. The dipole moment is determined to be 0.516(5) D.     

Formation,microwave spectrum and preliminary structure of selenoketene

Hitherto unknown selenoketene, CH₂CSe, has been produced by pyrolysis of 1,2,3-selenodiazole and identified by observation of microwave absorption from CH₂C&.dbnd;⁸⁰Se and CH₂C⁷⁸Se. The CC and CSe bond lengths of selenoketene agree with bond lengths in ketene, CH₂CO, and in carbonyl sulphide, OCS.     

The microwave spectrum,structure and centrifugal distortion constants of 2-chloroacrylonitrile

The microwave spectrum of 2-chloroacrylonitrile has been studied in the 26.5–40 GHz region. A total of 99 a- and b-type rotational transitions have been measured and assigned for CH₂ =C³⁵Cl(CN),yielding values for the rotational constants (in MHz): A = 6973.27, B = 3148.16, C = 2165.95. For CH₂=C³⁷Cl(CN) a total of 53 transitions have been measured and assigned and the rotational constants obtained are (in MHz): A = 6909.35, B = 3081.17, C = 2127.98. The distortion effects have also been studied and the quartic distortion constants have been evaluated. From the observed hyperfine structure, the chlorine nuclear quadrupole coupling constants have been obtained. The structure of vinyl cyanide and vinyl chloride can be transferred to account remarkably well for the observed rotational constants.     

The microwave spectrum of tellurophene

The microwave spectrum of tellurophene, C₄H₄Te, has been recorded between 8 and 27 GHz. The rotational constants obtained from least-squares fitting of low-J lines are:

Figures in parentheses are uncertainties in last place of decimal (95% confidence limit). Corresponding inertial defects are 0.094 (7), 0.095 (6) and 0.097 (10) amu A² respectively, indicating the essential planarity of the molecule.Stark shift measurements correspond to a dipole moment of μ_a = 0.619 x 10^?30 C m (0.186 D).An approximate structure, based on bond lengths of CC and CH bonds adopted from related molecules, implies that r (Te - C) = 205.5 pm and ? C (5) TeC (2) = 82.53°.     

The microwave spectrum of selenoformaldehyde

The microwave spectra of the four major isotopic species of the unstable molecule selenoformaldehyde have been assigned. The limited number of isotopic variants yields the following structure: r(CSe) = 175.9 pm, ∠(HCH) = 120.4° and r(CH) assumed to be 109 pm. The dipole moment is 1.41 ± 0.01 D.     

Conformational study of allyl fluoride,allyl alcohol and allyl amine through the matrix-isolation technique

In a vibrational analysis of allyl compounds, which was made difficult because of autoassociation and conformational equilibrium, we have used the matr     

The microwave spectrum of chloroacetyl chloride

The microwave spectrum, rotational constants and centrifugal distortion parameters for CH₂³⁵ClCO³⁵Cl are reported. The nuclear quadrupole coupling constants of the two non-equivalent Cl atoms were determined from partially resolved quadrupole splittings. The molecule is planar in the conformation studied here and both Cl atoms occupy the trans position as shown from their substitution coordinates.     

The microwave spectrum of dichloroacetic acid

The microwave spectrum of dichloroacetic acid consists of many weak absorption lines, of which only a small number has been identified. From the measured frequencies only two rotational constants could be obtained. Determination of the nuclear quadrupole coupling constants of the two chlorine atoms was not possible, since no line splittings were observed.Isotopic substitution of the two chlorine and the two hydrogen atoms shows that the assigned absorption lines belong to the conformation with the hydrogen atom gauche with respect to the hydroxylic group, while the carboxylic group has the common trans geometry. Substitution of the hydrogen atom of the dichloromethyl group by deuterium decreases the inertial moment I_c by 0.2 u Ų, indicating that structure determinations can be hampered by vibrational effects to an almost incredible extent.     

The microwave spectrum of acetaldehyde cyanohydrin

The microwave spectrum of acetaldehyde cyanohydrin shows two series of μ_aR branch transitions of almost equal intensity which are accompanied by similar patterns of vibrational satellites. The most probable explanation of these two series of lines consistent with the expected conformational behaviour of acetaldehyde cyanohydrin is that they belong to the two non-equivalent rotamers in which the hydroxyl group is gauche to the cyanide group.     

Estimation of allyl alcohol by chloramine-T

A simple but rapid and accurate method for the estimation of allyl in aqueous solution has been developed, based on its oxidation with chloramine-T at room temperature, in 0.5-1.0M hydrochloric acid medium. The reaction involves a two-electron change. The effect of such variables such as pH of the medium, presence of foreign ions and perchloric or sulphuric acid on the rate of oxidation is discussed.     

The microwave spectrum of methane sulphonyl chloride

The microwave spectrum of SO₂ClCH₃ was observed by means of Stark modulation and double resonance modulation. Rotational constants, centrifugal distortion parameters and nuclear quadrupole coupling constants are reported for the ³⁵Cl and ³⁷Cl species. An unambiguous choice between three possible electron diffraction structures could be achieved by the determination of the O-O distance.     

Kinetics and mechanism of oxidation of allyl alcohol byN-bromosuccinimide

The kinetics of oxidation of allyl alcohol byN-bromosuccinimide (NBS) has been studied at 35 °C in aqueous medium. The reaction shows first order dependence on bothNBS and allyl alcohol. In fairly high acid concentration, there is no change in the rate of the reaction but at low acid concentration, the rate is considerably enhanced. There is no primary salt effect. At varying mercuric acetate concentrations, the rate constant remains the same. But in the absence of mercuric acetate, the rate is enhanced. The kinetic parameters,E _a,Arrhenius factorA, H, G and S have been calculated. A rate law in agreement with experimental results has been derived. A mechanism is proposed.

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Kinetik und Mechanismus der Oxidation von Allylalkohol mixN-Bromsuccinimid

Zusammenfassung Die Kinetik der Oxidation von Allylalkohol mitN-Bromsuccinimid (NBS) wurde bei 35 °C in wäßrigem Medium untersucht. Die Reaktion zeigt erste Ordnung gegenüberNBS und Allylalkohol. Bei relativ hoher Säurekonzentration zeigt sich keine Änderung der Reaktionsgeschwindigkeit, bei niedriger Säurekonzentration wird die Reaktionsgeschwindigkeit beträchtlich erhöht. Es wurde kein primärer Salzeffekt festgestellt. Bei varriierender Quecksilberacetatkonzentration bleibt die Reaktionsgeschwindigkeit gleich, bei Abwesenheit von Quecksilberacetat wird jedoch die Geschwindigkeitskonstante erhöht. Die kinetischen Parameter,E _a, derArrheniusfaktorA, H , G und S wurden bestimmt. Ein Geschwindigkeitsgesetz in Übereinstimmung mit den experimentellen Befunden wurde abgeleitet und ein Mechanismus vorgeschlagen.

     

The microwave spectrum and dipole moment of 1,1-diflurobenzocyclopropene

The rotational spectrum of 1,1-difluorobenzocyclopropene, measured in the X- and R-bands, has been analysed to give the rotational constants in the ground and first four vibrational states. These constants are in agreement with a structure based on those of crystallographically determined related molecules. Indirect evidence is adduced that the carbon skeleton is indeed planar. The dipole moment in the ground (3.57₂ ± 0.02 D) and first excited state (3.54 ± 0.03 D) has been determined through an analysis of the second-order Stark effect. This high value implies considerable polarisation of the π-electron framework.     

含长叶烯结构硫氰酸烯丙酯和异硫氰酸烯丙酯的合成

研究ω-氯甲基长叶烯与不同硫氰酸盐的取代反应,选择性合成了含长叶烯结构的ω-硫氰甲基长叶烯和ω-异硫氰甲基长叶烯,采用FTIR、UPLC-QTOF/MS、1H NMR和13C NMR对产物进行结构表征.结果 表明,硫氰酸盐类型和反应体系对产物的选择性有较大影响.在60℃加热搅拌条件下,硬酸型阳离子K+、Na+和NH4+...