Action of Halogen

These compounds are obtained by action of halogenated organic derivatives on lead alloys (magnesium or alkaline metal alloys). 

Numerous carbonyl halides, of which the best known are octahedral compounds of the type [M(C0)4X2] are obtained by the action of halogen on Fe(CO)5, or CO on MX3 (M = Ru, Os). Stepwise substitution of the remaining CO groups is possible by X or other ligands such as N, P and As donors. 

Arbuzov, A.E. and Dunin, A.A., Action of halogen derivatives of aliphatic esters on alkyl phosphites, /. Russ. Phys. Chem. Soc., 46, 291, 1914. 

This series of compounds is formed by the action of halogen or nitric acid on tetrammino-platinous salts, or by the addition of ammonia to tetracido-diammino-platinuni compounds. 

A further general synthesis, resulting in 3-substituted 5-chloro-l,2, 4-thiadiazoles, has been found by Goerdeler88 and his co-workers in the action of halogenated methylmercaptans on compounds incorporating an amidino group. 

The differences observed between the susceptibilities of different hydrocarbons to the promoter action of halogen compounds are generally similar to those observed between their susceptibilities to the promoter action of nitrates (15). The explanation previously proposed for the different effects of nitrates (15) probably holds in this case also. 

The action of halogen acids on 2,3-epoxypentane was reported many years ago by Henry r7 who believed only a single product (o have been formed. The validity of this conclusion is questionable, however, and may bear revision. 

Epoxide rings in sugars have been opened by the action of halogen acids. Both possible products of ring scission were observed in the reaction of methyl 2,3-anhydro-4,6-O-benzylidene-a-D-alloside 8 with hydrobromic... 

Rubber stoppers should be occasionally rubbed with a little toluene, which prevents hardening and keeps them clean. A trace of vaseline smeared on a rubber stopper affords considerable protection from the actions of halogens. Rubber stoppers should always be removed from vessels while the latter are still warm, to prevent sticking to the glass. 

In this way secondary and tertiary amines may be obtained from primary. Quaternary compounds are obtained by prolonged action of an excess of halogen compound on primary amines, or more usually by the action of halogen compound on a tertiary amine. 

The action of halogen acids on alkyl 2,3-anhydro-aldosides results in the formation of an alkyl 2-halogeno- or 3-halogeno-desoxyaldoside which can readily be reduced to give the corresponding alkyl 2- or 3-desoxyaldoside. 

The higher halides of molybdenum, tungsten, and uranium, themselves prepared by the action of halogen on the element, yield tne lower halides on heating. They are volatile, coloured bodies, soluble in water the higher ones are decomposed by water. 

The action of hydrogen chloride on 152 (R =H) led only to a chlorine-free product which was assigned structure 155. Attempts to prepare selenazoles by the action of halogen acids on a-cyanoalkyl... 

The preparation of derivatives (167) of this ring system by the action of halogen acids on dicyanoguanidines (166) was reported by Kaiser and Roemer107,108 in 1953. Their patents undoubtedly represent the first specific applications of dinitrile cyclization to the synthesis of a heterocyclic system. Excellent yields of 167 were... 

The action of halogen acids on nitriles has received a considerable amount of attention, especially with regard to hydrogen chloride. Much of the literature has been reviewed by Zil berman," whose own work has helped to clarify some of the complexities of this area. 

Mechanism of Action of Halogenated Compounds in the Condensed Phase.82... 

The evidence for the action of halogen and halogen antimony compounds in the gaseous phase is well established however halogen-containing flame-retardant systems are often twofold systems providing radical action inhibition in the gaseous phase and, at the same time inhibition in the condensed phase as will be seen in the next section. 

MECHANISM OF ACTION OF HALOGENATED COMPOUNDS IN THE CONDENSED PHASE... 

The studies of fire-retardant action of halogenated compounds in the condensed phase were performed mostly on mixtures of chloroparaffin with vinyl polymers such as polyethylene,... 

As already seen in Section 4.3, the primary action of halogen fire-retardant action for polypropylene is in the gaseous phase, thus the fire-retardant additives for polypropylene are often based on aliphatic bromine compounds in order to develop bromine at its low ignition temperature. 

Halogenoisothiazoles are readily prepared by the action of halogens on the 5-lithium derivatives (see Section III,B) or by the Sandmeyer reaction from 5-aminoisothiazoles. 

The Halogens, Cl2, Br2, and I2 The action of halogens is dependent upon the conversion of electrically neutral halogen molecules into halogen ions by accepting electrons ... 

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