Parent hydrocarbon

There are multiple systems for naming organolithium compounds. In one, CeHsLi is named phenyl lithium and w-C4H9Li is w-butyl lithium. In another, these species are named Uthiobenzene and 1-lithiobutane, respectively, when the lithium atom is regarded as a substituent on the hydrocarbon parent. A third nomenclature approach assumes these species are ionic salts, e.g. the above two compounds are called lithium phenylide and lithium butylide. We will bypass any questions of aggregation by referring to these compounds by their monomeric names (e.g. phenyl lithium and not dimeric phenyl lithium, phenyl lithium dimer nor diphenyl dilithium), and where monomeric species are actually meant, we will make this explicit. 

A simple method for estimating enthalpies of vaporization is the CHLP protocol . The quantities and req in equation 1 refer respectively to the number of quaternary carbon atoms and non-quaternary carbon atoms in the compound, and is a value that is characteristic of the functional group bonded to the hydrocarbon parent. 

Reduction of the three isomeric pyridylcarbinols (29-31) (Scheme 10) leads to products similar to reduction of the hydrocarbon parents 15, 16, and 19 (Scheme 5).58 One should note, however, that the product ratios are different (Table IV). In the case of the 3-isomer (30), the unsaturated product (32) is exocyclic in this report, whereas it is endocyclic (18) in a previous report of the reduction of -picoline (16). Ferles and Tesarova give IR evidence for 32 here and identify 18 by derivatization.35 The IR evidence would seem to be more valid. In contrast to 30, the 3-pyridylmethylcarbinol (33) gave endocyclic piperideines 34 and 35 (Scheme 11). For the pyridylmethylcarbinols 36 and 37, the product ratios were different and the 3-isomer (36) gave a mixture of exocyclic and endocylic piperideines, but mostly exo-(38) (Scheme 12). 

The 3,3,4,4)5,6,6-heptafluoro-5-hexenyl radical, 18, exhibits very little rate enhancement relative to the hydrocarbon parent (krd = 1.6), and its rate constant is virtually the same as that of the perfluoro radical, 11. A recent study of the reactivity of RFCH2CH2- - type radicals demonstrated that they do not exhibit electrophilic character in their additions to alkenes [70]. They are 7i-radicals with a reactivity profile much like that of an n-alkyl radical. 

The slight enhancement observed for cyclization of radical 20 is consistent with the slight electrophilicity of such radicals which was demonstrated earlier in the studies of their bimolecular olefin addition reactivity [70], The similar reactivities of 20 and hydrocarbon parent are consistent with the similarity of the ESR parameters for these two types of radicals [169]. That is they are both effectively planar rr-radicals. 

Enthalpies of fusion are taken from Reference 7 and enthalpies of sublimation from Reference 8. Where data for vaporization enthalpies are lacking, we will use the CHLP protocol9 to estimate them. The derived values assume that the enthalpy of vaporization depends only on the number of carbons in the molecule and the identity of the substituent affixed to the hydrocarbon parent. 

Unambiguous parent names for non-carbon-containing heteronuclear chains can be derived from a hydrocarbon parent or a non-carbon homonuclear chain parent (cf. Section IR-6.2.2.1). Alternatively, heteronuclear chains may be named additively by the method described in Section IR-7.4. However, such names cannot be used as parent names in substitutive nomenclature. 

The millions of organic compounds other than hydrocarbons can be regarded as derivatives of hydrocarbons, where one (or more) of the hydrogen atoms on the parent molecule is replaced by another kind of atom or group of atoms. The compound is often named in a manner that designates the hydrocarbon parent from which it was derived. The hydrocarbon part of the molecule is often called the radical and is denoted R in formulas. The names of some common radicals are hsted in Table 14.2. 

Saturated hydrocarbons Parent PAH Compounds Nitro-PAH, monosubstituted Multinitropyrenes Highly polar compounds... 

On the other hand, it is well known that perfluoro arenes, for example, hexafluoro-benzene or octafluoronaphthalene, form some type of complex with their hydrocarbon parent compounds, having melting points higher than those of the pure components [76]. Very recently, the deuterium NMR spectra of the octafluoronaphthalene/ naphthalene system have been explained in terms of a highly ordered columnar mesophase [76 d]. However, the face-to-face stacking in such solids and also in liquids is... 

In addition, names may be formed from any hydrocarbon by indicating replacement of a ring member by, for instance, oxygen, sulphur, or nitrogen by oxa-, thia-, aza-prefixes, respectively. The numbering of the hydrocarbon is retained by this procedure, and if more than one kind of heteroatom is present they are cited in a prescribed order (e.g.j that just given). An example would be 8ff-7-thia-l,9-diaza-phenanthrene (XXI). This nomenclature must be applied to the hydrocarbon parent , not to a... 

The generic term azulene was first applied to the blue oils obtained by distillation, oxidation, or acid-treatment of many essential oils. These blue colours are usually due to the presence of either guaiazulene or velivazulene. The parent hydrocarbon is synthesized by dehydrogenation of a cyclopentanocycloheptanol or the condensation of cyclopentadiene with glutacondialdehyde anil. 

The high acidity of superacids makes them extremely effective pro-tonating agents and catalysts. They also can activate a wide variety of extremely weakly basic compounds (nucleophiles) that previously could not be considered reactive in any practical way. Superacids such as fluoroantimonic or magic acid are capable of protonating not only TT-donor systems (aromatics, olefins, and acetylenes) but also what are called (T-donors, such as saturated hydrocarbons, including methane (CH4), the simplest parent saturated hydrocarbon. 

Carbon atoms can also form cyclic compounds. Aromatic hydrocarbons (arenes), of which benzene is the parent, consist of a cyclic arrangement of formally unsaturated carbons, which, however, give a stabilized (in contrast to their hypothetical cyclopolyenes), delocalized system. 

The reverse reaction of the protolytic ionization of hydrocarbons to carbocations, that is, the reaction of trivalent carbocations with molecular hydrogen giving their parent hydrocarbons, involves the same five-coordinate carbonium ions. 

Protonation of formic acid similarly leads, after the formation at low temperature of the parent carboxonium ion, to the formyl cation. The persistent formyl cation was observed by high-pressure NMR only recently (Horvath and Gladysz). An equilibrium with diprotonated carbon monoxide causing rapid exchange can be involved, which also explains the observed high reactivity of carbon monoxide in supera-cidic media. Not only aromatic but also saturated hydrocarbons (such as isoalkanes and adamantanes) can be readily formylated. 

We conclude this introduction to hydrocarbons by describing the orbital hybridization model of bonding m ethylene and acetylene parents of the alkene and alkyne families respectively... 

Benzene is the parent of a class of hydrocarbons called arenes, or aro matic hydrocarbons... 

Compounds with two ammo groups are named by adding the suffix diamine to the name of the corresponding alkane or arene The final e of the parent hydrocarbon IS retained... 

Trivalent groups derived by the removal of three hydrogen atoms from the same carbon are named by replacing the ending -ane of the parent hydrocarbon with -ylidyne. 

Radicals derived from monocyclic substituted aromatic hydrocarbons and having the free valence at a ring atom (numbered 1) are named phenyl (for benzene as parent, since benzyl is used for the radical C5H5CH2—), cumenyl, mesityl, tolyl, and xylyl. All other radicals are named as substituted phenyl radicals. For radicals having a single free valence in the side chain, these trivial names are retained ... 

The physical properties of cyanoacetic acid [372-09-8] and two of its ester derivatives are Hsted ia Table 11 (82). The parent acid is a strong organic acid with a dissociation constant at 25°C of 3.36 x 10. It is prepared by the reaction of chloroacetic acid with sodium cyanide. It is hygroscopic and highly soluble ia alcohols and diethyl ether but iasoluble ia both aromatic and aUphatic hydrocarbons. It undergoes typical nitrile and acid reactions but the presence of the nitrile and the carboxyUc acid on the same carbon cause the hydrogens on C-2 to be readily replaced. The resulting malonic acid derivative decarboxylates to a substituted acrylonitrile ... 

The methyl and ethyl esters of cyanoacetic acid are slightly soluble ia water but are completely miscible ia most common organic solvents including aromatic hydrocarbons. The esters, like the parent acid, are highly reactive, particularly ia reactions involving the central carbon atom however, the esters tend not to decarboxylate. They are prepared by esterification of cyanoacetic acid and are used principally as chemical iatermediates. 

The common method of naming aldehydes corresponds very closely to that of the related acids (see Carboxylic acids), in that the term aldehyde is added to the base name of the acid. For example, formaldehyde (qv) comes from formic acid, acetaldehyde (qv) from acetic acid, and butyraldehyde (qv) from butyric acid. If the compound contains more than two aldehyde groups, or is cycHc, the name is formed using carbaldehyde to indicate the functionaUty. The lUPAC system of aldehyde nomenclature drops the final e from the name of the parent acycHc hydrocarbon and adds al If two aldehyde functional groups are present, the suffix -dialis used. The prefix formjlis used with polyfunctional compounds. Examples of nomenclature types are shown in Table 1. 

Ketones oxidize about as readily as the parent hydrocarbons or even a bit faster (32). Although the reactivities of hydrogens on carbons adjacent to carbonyl groups are perhaps doubled, the effect is small because one methylene group is missing in comparison to the parent hydrocarbon. Ketones oxidize less readily than similar primary or secondary alcohols (35). 

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