Halogens Group hydrogen halides

Reactions of the organometallic compounds InCp and TlCp with halogens and hydrogen halides involve attack on the cyclopentadienyl group . However, I2 reacts with InCp by oxidative addition to yield Cplnl2 , which forms adducts with suitable donor ligands (e.g., 2,2 -dipyridyl). Loss of the cyclopentadienyl ligand accompanies... 

Reactions at a Group Viii Metal Center The Ni, Pd, Pt Triad 10.3.8.6. Reactions of Halogens and Hydrogen Halides... 

Except for trimethylboron, which is a gas at room temperature, the trialkylborons are colorless liquids, but the triarylborons are crystalline. Unlike the alkyl derivatives of other elements of the Third Group, alkylborons are monomeric they are unaffected by water but react with halogens and hydrogen halides, yielding organic boron halides. 

Gattermann s reaction A variation of the Sandmeyer reaction copper powder and hydrogen halide are allowed to react with the diazonium salt solution and halogen is introduced into the aromatic nucleus in place of an amino group. 

A halogen atom directly attached to a benzene ring is usually unreactive, unless it is activated by the nature and position of certain other substituent groups. It has been show n by Ullmann, however, that halogen atoms normally of low reactivity will condense with aromatic amines in the presence of an alkali carbonate (to absorb the hydrogen halide formed) and a trace of copper powder or oxide to act as a catalyst. This reaction, known as the Ullmant Condensation, is frequently used to prepare substituted diphenylamines it is exemplified... 

The reaction of an alcohol with a hydrogen halide is a substitution A halogen usually chlorine or bromine replaces a hydroxyl group as a substituent on carbon Calling the reaction a substitution tells us the relationship between the organic reactant and its prod uct but does not reveal the mechanism In developing a mechanistic picture for a par ticular reaction we combine some basic principles of chemical reactivity with experi mental observations to deduce the most likely sequence of steps... 

Hydrogen halides can, in some cases, be used to replace an atom or group by halogen Fluoropentamtrobenzene reacts with hydrogen chloride to yield 3-chloro-2,4,5,6-tetranitrofluorobenzene, but the other halopentanitrobenzenes are much less reactive [54] (equation 37)... 

These reactions give products similar to those described in 8.3.2.1. Transition-mclal hydrido complexes react with a halogen derivative of a group-IB metal to form a hydrogen halide and the required metal-metal bond ... 

Remarks on 1 and 2.—These two reactions are special cases of a general change, namely, the substitution of an alcoholic hydroxyl group by a halogen atom. This substitution can be carried out in two ways first, as in the preparation of ethyl bromide, 1, by acting on alcohols with hydrogen halides, e.g. 

An alkyl halide (also known as a haloalkane) is an alkane in which one or more hydrogen atoms have been replaced with halogen atoms, such as F, Cl, Br, or I. The functional group of alkyl halides is R—X, where X represents a halogen atom. Alkyl halides are similar in structure, polarity, and reactivity to alcohols. To name an alkyl halide, first name the parent hydrocarbon. Then use the prefix fluoro-, chloro-, bromo-, or iodo-, with a position number, to indicate the presence of a fluorine atom, chlorine atom, bromine atom, or iodine atom. The following Sample Problem shows how to name an alkyl halide. 

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