Organic substituents

Step 2 Disconnect one of the organic substituents attached to the carbon that bears the hydroxyl group... 

Quantum (Section 13 1) The energy associated with a photon Quaternary ammonium salt (Section 22 1) Salt of the type R4N X The positively charged ion contains a nitrogen with a total of four organic substituents (any combination of alkyl and aryl groups)... 

The presence of carbon—fluorine bonds in organic polymers is known to characteristically impart polymer stabiUty and solvent resistance. The poly(fluorosibcones) are siloxane polymers with fluorinated organic substituents bonded to siUcon. Poly(fluorosibcones) have unique appHcations resulting from the combination provided by fluorine substitution into a siloxane polymer stmcture (see Silicon compounds, silicones). 

The versatility of lithium aluminum hydride permits synthesis of alkyl, alkenyl, and arylsilanes. Silanes containing functional groups, such as chloro, amino, and alkoxyl in the organic substituents, can also be prepared. Mixed compounds containing both SiCl and SiH cannot be prepared from organopolyhalosilanes using lithium aluminum hydride. Reduction is invariably complete. 

Preparation. Substituted A/-halamines are usually prepared by reaction of RR NH with halogen, hypohalous acid, or hypohaUte where R is an organic substituent and R is either an organic substituent or H. 

The color and constitution of cyanine dyes may be understood through detailed consideration of their component parts, ie, chromophoric systems, terminal groups, and solvent sensitivity of the dyes. Resonance theories have been developed to accommodate significant trends very successfully. For an experienced dye chemist, these are useful in the design of dyes with a specified color, band shape, or solvent sensitivity. More recendy, quantitative values for reversible oxidation—reduction potentials have allowed more complete correlation of these dye properties with organic substituent constants. 

Three different conformations are possible for monomeric chalcogen diimides (Eig. 10.1). Variable-temperature NMR spectra indicate that the cis,trans isomer of S(NR)2 is most stable in solution for small organic groups (R = Me, Bu). With bulkier organic substituents, small amounts of the trans,trans isomer exist in equilibrium with the cis,cis isomer. " The cis,cis isomer is observed in solutions of certain sulfur diimides with... 

Simple ethers with no other functional groups are named by identifying the two organic substituents and adding the word ether. 

Amine (Chapter 24 introduction) A compound containing one or more organic substituents bonded to a nitrogen atom, RNH2, R2NH, or R3N. 

Ether (Chapter 18 introduction) A compound that has two organic substituents bonded to the same oxygen atom, ROR . 

Ketone (Chapter 19 introduction) A compound with two organic substituents bonded to a carbonyl group, R2C = 0. 

In addition to one or more sugars, exopolysaccharides from prokaryotes commonly contain pyruvate ketals and various ester-linked organic substituents. These are only rarely found in eukaryotic exopolysaccharides. 

Exchange of organic substituents at the sulphinyl sulphur atom. . 361... 

F unctionalization of organic substituents adjacent to the sulphoxide moiety constitutes an important method of the synthesis of a variety of sulphoxides, which are not available by the methods described in the previous sections. Such transformations enable one to synthesize a large number of very sophisticated sulphoxides which are required for special purposes or serve as a source of many sulphur-free organic compounds. 

Since a great number of such transformations were described in the chemical literature, only selected examples of general importance will be presented here. This section will consist of the following parts reactions of the sulphoxide a-carbanions introduction, substitution, transformation and elimination of heteroatomic groups attached to organic substituents in sulphoxides additions to unsaturated sulphoxides other modifications of organic substituents in sulphoxides. 

B. introduction, Substitution, Transformation and Elimination of Heteroatomic Groups at Organic Substituents in Sulphoxides... 

Table 9. Effect of organic substituents on the solubility parameter and the glass transition temperature of an organosiloxane polymer...

Thus, attempts to isolate and characterize stable, singly bonded R2M—MR2 species with common organic substituent groups such as Me, Et, z-Bu, or Ph were generally unsuccessful. However, in 1988 Uhl and coworkers showed that... 

The poly(phosphazene) backbone can be made to be part of a fully inorganic polymer by replacing the organic substituents with chlorines, thus generating poly(dichlorophosphazene). However, this is a reactive molecule and is more usually employed as the starting material for the preparation of the various partially organic poly(phosphazenes). 

The reactions discussed here, however, disobey this strong definition as oxidation of the metal is often accompanied by an elimination of hydrogen or of organic substituents. Nevertheless, these reactions are best described in this section. 

Preparation of poly(dichlorophosphazene), (NPCl2)n> a polymeric intermediate from which the great majority of POPs have been prepared by nucleophilic substitution of the highly reactive chlorine atoms with carefully selected organic substituents... 

If we consider the LOI values reported in Table 8, it can be clearly seen that the flame resistance of polyphosphazenes is very high and can reach values above 60 when halogenated phenoxy groups (e.g. 4-bromophenoxy) are attached to the polymer chain. However, enhancement of the carbon content in the materials (i.e. by increasing the percentage of organic substituents in the chain) induces a concurrent decrease in the flame resistance of POPs, which can be depressed to 23.4 in the case of poly[bis(4-/sopropylphenoxy)phos-phazene]. 

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