Preparation electric discharge

Boron sub-iodide, B2I4, is prepared by the action of an electrical discharge on BI vapour. 

Beams of metal atoms have been prepared by many researchers tlirough thennal vaporization from a heated cmcible. An example of such a source, employed for the generation of beams of alkaline earth atoms, is described by Irvin and Dagdigian [H]. By striking an electrical discharge within this source, beams... 

Xenon dichloride [13780-38-6], XeCl, and xenon(II) chloroduoride [73378-52-6], XeClE, have been prepared by photochemical and electric discharge methods and have been examined at low temperatures by matrix-isolation techniques (39,40). The dichloride has a linear stmcture like that of XeE2. Evidence for the existence of XeCl2, XeBr2, and xenon tetrachloride [14989-42-5], XeCl, has been obtained from Mn ssbauer studies (41,42). Owing to thermal chemical instabiUties, no dihaUde other than the binary duorides has been prepared in macroscopic amounts. 

Commercial production and utilization of ozone by silent electric discharge consists of five basic unit operations gas preparation, electrical power supply, ozone generation, contacting (ie, ozone dissolution in water), and destmction of ozone in contactor off-gases (Fig. 1). 

Carbon monosulfide [2944-05-0] CS, is an unstable gas produced by the decomposition of carbon disulfide at low pressure ia a silent electrical discharge or photolyticaHy (1 3) ia the presence or absence of sulfur (3). It decomposes with a half-life of seconds or minutes to a black soHd of uncertain composition (1—3). The monosulfide can be stabilized ia a CS2 matrix at — 196°C, and many stable coordination complexes of CS with metals have been prepared by iadirect means (8). 

C/o50-carboranes are the most numerous and the most stable of the carboranes. They are colourless volatile liquids or solids (depending on mol wt.) and can be prepared from an alkyne and a borane by pyrolysis, or by reaction in a silent electric discharge. This route, which generally gives mixtures, is particularly useful for small c/o50-carboranes (n = 5-7) and for some intermediate c/ow-carboranes (n = 8-11), e.g. 

B2CI4 was the first compound in this series to be prepared and is the most studied it is best made by subjecting BCI3 vapour to an electrical discharge between mercury or copper electrodes ... 

Dioxygen difluoride, O2F2, is best prepared by passing a silent electric discharge through a low-pressure mixture of F2 and O2 the products obtained depend markedly on conditions, and the... 

Fibers of titanium diboride can be prepared by reaction (a) at 400°C in an electrical discharge. Adherent layers of certain metal borides on metal substrate surfaces are obtained by thermal decomposition of metal (Mo, W, Nb, Ta) halides and BBr3 on a metallic substrate using a solar furnace or induction heating ... 

More direct and successful methods for the preparation of non-aqueous metal sols are desirable. Especially valuable would be a method that avoids the metal salt reduction step (and thus avoids contamination by other reagents), avoids electrical discharge methods which decompose organic solvents, and avoids macromolecule stabilization. Such a method would provide pure, non-aqueous metal colloids and should make efficient use of precious metals employed. Such colloids would be valuable technologically in many ways. They would also be valuable to study so that more could be learned about particle stabilization mechanisms in non-aqueous media, of which little is known at the present time. 

It can also be prepared from carbon and nitrogen by electric discharge between carbon electrodes in a nitrogen atmosphere. Numerous derivatives of cyanogens are known, including cyanogen halides, XCN. These compounds form trimers known as the cyanuric halides, which have the cyclic structure... 

Electric discharge in a mixture of PC13 and H2 produces P2C14, and white phosphorus dissolved in carbon disulfide reacts with I2 to produce P2I4. All of the trihalides of the group VA elements are known, and they can be prepared by reaction of the elements, although there are other preparative methods. The fluorides are prepared as follows ... 

The difference in the ionization potentials of xenon and krypton (1170 versus 1351 kj/mol) indicates that krypton should be the less the reactive of the two. Some indication of the difference can be seen from the bond energies, which are 133 kj/mol for the Xe-F bond but only 50 kj/mol for the Kr-F bond. As a result, XeF2 is considerably more stable of the difluorides, and KrF2 is much more reactive. Krypton difluoride has been prepared from the elements, but only at low temperature using electric discharge. When irradiated with ultraviolet light, a mixture of liquid krypton and fluorine reacts to produce KF2. As expected, radon difluoride can be obtained, but because all isotopes of radon undergo rapid decay, there is not much interest in the compound. In this survey of noble gas chemistry, the... 

It should be added that ethenedithione (115) can also be prepared by an electric discharge in a mixture of CS2 and argon.147 As in the photo-dimerization of CS it can be assumed that in both cases one CS molecule is excited to the triplet state and then adds another singlet CS to form triplet C2S2 T-115. 

To sum up it can be said that all monosulfides C =S with n = 1-4 have been matrix-isolated and identified. The next member C5S has been prepared by electric discharge in a mixture of CS2, C2H2 and argon and observed by its rotational spectrum.149 The expected multiplicities and spectral data121,122,150 are verified by the experimental observations. 

---