VOCl3 Research Articles

Thermochemistry of vanadium oxytrichloride and vanadium oxytrifluoride by mass spectrometry

Thermochemistry of vanadium oxytrichloride and vanadium oxytrifluoride by mass spectrometry

Die Molekülstruktur des Vanadium-(N-chlorimid)-trichlorids, Cl3V=NCl, und des Vanadiumoxidtrichlorids, Cl3V = O, in der Gasphase / The Gas Phase Molecular Structure of Vanadium(N-Chlorimide)Trichloride, Cl3V=NCl, and Vanadium Oxide Trichloride, Cl3V=O

The molecular structures of Cl3V = NCl and Cl3V = O were determined by gas-phase electron diffraction. For both molecules the rα 0-structure was converted to restructure. In the case of Cl3V=O the necessary corrections were taken from the literature while for Cl3V=NCl an approximate force field was evaluated from the infrared spectra of the solid compound for calculating these corrections. The following rα0 parameters were derived for Cl3V = NCl: V = N = 1,651 (6), N-Cl = 1,597 (8), V - Cl = 2,138 (2), ⦓ ClVCl = 113,4° (0,3) and ⦓ VNCl = 169,7° (4,2). The most interesting result of this investigation is the structure of the V = N -Cl group which is almost linear and has a very short N -CI bond distance. Concerning the VNCl group the gas-phase results agree very well with the crystal structure. For vanadyl chloride the following rα0-values were obtained: V = 0 = 1,571 (4), V - Cl = 2,137 (1) and ⦓ ClVCl = 111,0° (0,1°). The error limits given in thousandth parts of an Angstrom or degrees are the threefold standard deviations of the least squares analysis.

Molecular structure of vanadyl(V) chloride as studied by gas electron diffraction

The molecular structure of OVCl 3 has been determined as follows by an analysis of electron diffraction intensities combined with the rotational constants for OV 35Cl 3, OV 37Cl 3 andOV 35Cl 2 37Cl determined in a previous microwave study: r g(VCl) = 2.142 ± 0.002 Å, r g(OV) = 1.570 ± 0.005 Å, r g(Cl⋯Cl) = 3.530 ± 0.002 Å and <ClVCl (r av) = 111.3 ± 0.1°. The uncertainties represent estimated limits of error. An isotopic difference in the VCl distance, r av(V− 35Cl)−r av(V− 37Cl), is estimated to be (6 ± 4) ×10 -5 Å.

Studies on proaporphine and aporphine alkaloids. Part V. Synthesis of (±)-glaziovine by 8,1′-ring closure of 1-benzylisoquinoline derivatives

A new, convenient synthesis of (±)-glaziovine (N-methylcrotsparine)(1) has been devised, involving as the key steps the nitration of (±)-4′-O-benzyl-N-methylcocclaurine (21), followed by catalytic hydrogenation to (±)-8-amino-N-methylcoclaurine (23), diazotization, and irradiation of the o-diazo-oxide (24). The synthesis of (±)-glaziovine by irradiation of (±)-8-bromo-N-methylcolaurine has been reinvestigated and improved. An attempted phenolic coupling reaction of (±)-N-trifluoroacetylcrotsparine (2) by vanadium oxide trichloride resulted in 8-chlorination and 4-hydroxylation [to give compounds (8) and (9)].

Schwingungsberechnungen der isotopen VOCl3-Moleküle, des VOBr3 und der Verbindungen VOCln Br3-n , sowie einige Molekularkonstanten der Titelverbindungen

Abstract In order to determine the isotopic splittings of the vibrational frequencies of isotopieally substituted vanadium oxytrichloride and to present the correlation between VOCl3 and VOBr3 a set of force fields was constructed for the isotopic species of VOCl3 , VOCl2Br, VOCIBr2, and VOBr3 . The conventional descriptions of the fundamentals are supported by the calculated potential energy distribution in all cases. Furthermore the calculations of certain molecular constants such as the mean amplitudes, their corresponding K-values, the Coriolis coupling constants of the -type and some thermodynamic quantities have been performed.

Kinetics of the deactivation of propagation centres during the copolymerization of ethylene and propylene in the presence of non-equilibrium catalysts based on vanadium oxychloride

The copolymerization of ethylene and propylene in the presence of “non-equilibrium” catalyst systems was investigated. The copolymerization of the monomers proceeds on propagation centres of a single type which are subject to deactivation simultaneously through bimolecular and monomolecular laws with the former greatly predominating. The proposed new equations describe the kinetic regularities of ethylene-propylene copolymerization in presence of non-equilibrium catalysts based on VOCl 3 and organoaluminium compounds.

Polymerization studies using modified Ziegler-Natta catalysts: 1. Polymerization of vinyl chloride

The polymerization of vinyl chloride by a number of modified Ziegler-Natta catalysts has been investigated. The most effective catalyst system is the soluble system prepared from vanadium oxytrichloride, tri-isobutylaluminium, and tetrahydrofuran. All three components are necessary for the formation of an active catalyst. The kinetics of the polymerization of vinyl chloride by this catalyst system has been examined at 30°C, and the dependence of the overall rate of polymerization on the transition halide concentration, aluminium alkyl concentration, monomer concentration and temperature established. Kinetic and copolymerization studies indicate that the polymerization process is not free radical in nature but is similar to that encountered in more conventional Ziegler-Natta systems.

Polymerization studies using modified Ziegler-Natta catalysts: 2. Polymerization of vinyl fluoride

Vinyl fluoride has been polymerized by modified Ziegler-Natta catalysts. As in the case of vinyl chloride the most effective catalyst system at 30°C is the soluble system prepared from vanadium oxytrichloride, tri-isobutylaluminium and tetrahydrofuran. All three components are necessary for the formation of an active catalyst. The overall kinetics of polymerization follow the general pattern observed in many Ziegler-Natta systems and that observed in the polymerization of vinyl chloride by the same catalyst system.

The reaction of copper with vanadium oxytrichloride and vanadium tetrachloride: The compound cuVCl 4

The reaction of copper with vanadium oxytrichloride and vanadium tetrachloride: The compound cuVCl 4

MICROWAVE SPECTRUM AND STRUCTURE OF VANADYL(V) CHLORIDE

Abstract The microwave spectrum of vanadyl(V) chloride was measured, and the following rotational constants (in MHz) were determined: Bo =1741.72±0.01 for OV35Cl3, Bo =1665.20±0.02 for OV37 Cl3, Ao =1739.94±0.05, Bo =1692.17±0.05, Co =1139±1 for OV35Cl237Cl. From these constants the ro structure was determined: r(V–O)=1.595±0.005 Å, r(V–Cl)=2.131±0.001 Å and ∠(Cl–V–Cl)=111.8±0.2°.

Covalency in cesium vanadyl chloride monohydrate as measured by nuclear quadrupole resonance spectroscopy

Covalency in cesium vanadyl chloride monohydrate as measured by nuclear quadrupole resonance spectroscopy

The Raman spectra of the vanadium oxytrihalides in the vapour, dissolved, and solid states, and of the mixed oxytrihalides

The Raman spectra of vanadium oxytrichloride and vanadium oxytribromide have been recorded as solid films at ca. 77 K. Evidence is presented for the formation of only one solid phase by the former (a phase which is not isomorphous with that of phosphorus oxytrichloride) but of two or three phases by vanadium oxytribromide. Values for the fundamentals of these molecules in cyclohexane solutions are also given. The vapour spectrum of vanadium oxytrifluoride has been obtained, and the values for the fundamentals and the band contours are compared with the correspondingly determined i.r. values and band contours. The vapour spectrum of vanadium oxytrichloride has likewise been recorded, and the contradiction between the i.r. and Raman assignments for the lowestlying fundamental (125 cm–1) has been resolved in favour of its assignment to an e mode. Vanadium oxytribromide is not sufficiently stable in the vapour phase to allow its Raman spectrum to be determined. Liquid mixtures of vanadium oxytrichloride and vanadium oxytribromide are found to contain approximately statistical proportions of the mixed halogeno-species VOCl2Br and VOClBr2. Assignments for the fundamentals of these mixed species are also presented. One fundamental of the molecule VOCl2F has also been located.

Behaviour of some vanadium(V) and chromium(VI) compounds in disulphuric acid

Abstract Vanadium pentoxide, vanadyl chloride and ammonium metavanadate form H[VO(HSO 4 ) 4 ] when dissolved in disulphuric acid. This compound behaves as a non-electrolyte in the acid. At higher concentrations, there is indication of its polymerisation. Chromyl chloride, potassium chromate and dichromate form CrO 2 (HSO 4 ) 2 when dissolved in disulphuric acid. There is also indication of the polymerisation of CrO 2 (HSO 4 ) 2 at higher concentration.

Electron paramagnetic resonance investigation of transition metal complexes. XV. Complexes of vanadyl chloride with tertiary phosphines

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectron paramagnetic resonance investigation of transition metal complexes. XV. Complexes of vanadyl chloride with tertiary phosphinesG. Henrici-Olive and S. OliveCite this: J. Am. Chem. Soc. 1971, 93, 17, 4154–4157Publication Date (Print):August 1, 1971Publication History Published online1 May 2002Published inissue 1 August 1971https://doi.org/10.1021/ja00746a010RIGHTS & PERMISSIONSArticle Views185Altmetric-Citations9LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (411 KB) Get e-Alerts Get e-Alerts

Mechanical properties of alternating copolymers of acrylonitrile and butadiene

AbstractThe alternating copolymer was prepared from butadiene (BD) and acrylonitrile (AN) with ethylaluminum dichloride as a complexing agent and with vanadyl chloride as a catalyst, and was investigated to explain effects of composition and sequence distribution on the physical properties, especially the viscoelastic properties and the ultimate mechanical properties. In the unvulcanized state, the viscoelastic properties of the alternating rubber is not essentially different from the random one, except for a slight difference in the relaxation spectra. However, the vulcanized rubbers show different shift factors. The latter depends upon the glass transition temperature (Tg.) Since the alternating copolymer possesses a Tg lower than the random one, the nature of the alternating copolymer corresponds to that of the random copolymer having an AN content of 40%. The difference in dynamic properties can be expressed with the different shift factors. In the isofree‐volume state or at the temperature Tg + 25°C, the rubbers having various acrylonitrile contents and various degrees of alternation exhibit almost the same dynamic properties. However, the strain at break of the alternating rubber is higher than that of the random one. The temperature of maximum strain increases with increasing degree of alternation. The alternating rubber shows higher stress at break than the random one. The stiffness of the chain of the alternating copolymer is smaller than the random copolymer; in other words, the molecular chain of the former is more flexible than the latter. It can be said that the alternating copolymer is an excellent rubber having high tensile strength and elongation at break.

Electron acceptor–electron donor interactions. Part XIX. Charge-transfer interactions of some of the highest-valency halides, oxyhalides, and oxides with aromatic hydrocarbons and fluorocarbons. Ball–plane interactions. Group VA

Vanadium oxytrichloride, pentafluoride, and oxytrifluoride, and niobium and tantalum pentachlorides, oxytrichlorides, and pentafluorides are examined. Intermolecular charge-transfer spectra are established for aromatic hydrocarbons or fluorocarbons with vanadium oxytrichloride, niobium and tantalum pentachlorides, and possibly in one case vanadium pentafluoride. The vanadium oxytrichloride interactions are extremely weak or just contact in terms of equilibrium measurements for the solvents cyclohexane and carbon tetrachloride, and in terms of the effect of temperature on the benzene and naphthalene spectra. Thermochromism, namely coloured liquids that freeze to solids the colour of the components, occurs for vanadium oxytrichloride and tantalum pentachloride with benzene and octafluoronaphthalene. Equilibrium constants for the niobium and tantalum pentachloride interactions also show them to be very weak, although the derived enthalpies, ca. 1·5 kcal mol–1, though small, are the largest in this series of papers. It is speculated that the extended dimer structures may afford more favourable conditions for molecular association. The remaining halides and oxyhalides do not show intermolecular spectra, but in some cases react chemically. For comparable molecular species, increasing electron affinities occur in the order Ta < Nb < V.

Studies on the syntheses of heterocyclic compounds. Part CCCLXXXII. Phenolic oxidative coupling of reticuline by use of various reagents

The phenolic oxidative coupling of reticuline (III) to give pallidine (IV) and isoboldine (V), with the reagents potassium ferricyanide, vanadyl trichloride, and silver carbonate, has been examined. The reactions of p-cresol with silver carbonate and with silver nitrate are also described.

Copolymerization of ethylene and propylene in systems containing vanadium oxychloride and an alkylaluminium halide, modified with tetrahydrofuran

Copolymerization of ethylene and propylene in systems containing vanadium oxychloride and an alkylaluminium halide, modified with tetrahydrofuran

Spectrophotometric determination of trace vanadium oxytrichloride in titanium tetrachloride

A simple method is described for determining vanadium(V) as vanadium oxytrichloride in titanium tetrachloride after dissolution in hydrochloric acid. In this system diphenylbenzidine is oxidized by vanadium(V) to produce a violet colored solution. Spectrophotometric measurements are made at 575 nm. The procedure is designed for the measurement of vanadium in titanium tetrachloride at the 2–10 p.p.m. level.

The nature of the decomposition of phenylvanadium oxide dichloride

The reaction of diphenylmercury and vanadium oxide trichloride in cyclohexane solution at 25° initially yielded phenylmercuric chloride and the unstable phenylvanadium oxide dichloride whose decomposition has been studied. When a diphenylmercury/vanadium oxide trichloride ratio > 1 was employed, the biphenyl formation rate was accelerated and more than one chlorine on the vanadium was replaced by a phenyl group. When this ratio was < 1, the rate of biphenyl appearance was retarded and, on acid hydrolysis, benzene, phenol and biphenyl were recovered. It was shown that all cyclohexane-soluble, phenyl-bearing species ( e.g. Ph n VOCl 3- n , Ph 2Hg) interchanged phenyl groups very rapidly. The appearance of biphenyl was thought to be due to the concerted decomposition of an unstable di-σ-phenylvanadium intermediate.