Functionalizing hydrocarbons with

Alkanes are a class of saturated hydrocarbons with the general formula C H2n. -2- They contain no functional groups, are relatively inert, and can be either straight-chain (normal) or branched. Alkanes are named by a series of IUPAC rules of nomenclature. Compounds that have the same chemical formula but different structures are called isomers. More specifically, compounds such as butane and isobutane, which differ in their connections between atoms, are called constitutional isomers. 

Ionic polymers are a special class of polymeric materials having a hydrocarbon backbone containing pendant acid groups. These are then neutralized partially or fully to form salts. lonomeric TPEs are a class of ionic polymers in which properties of vulcanized rubber are combined with the ease of processing of thermoplastics. These polymers contain up to 10 mol% of ionic group. These ionomeric TPEs are typically prepared by copolymerization of a functionalized monomer with an olefinic unsamrated monomer or direct functionalization of a preformed polymer [68-71]. The methods of preparation of various ionomeric TPEs are discussed below. 

In hydrocarbon liquids other than n-hexane, the procedure for obtaining the thermalization distance distribution could conceivably be the same. However, in practice, a detailed theoretical analysis is rarely done. Instead, the free-ion yield extrapolated to zero external field (see Chapter 9) is fitted to a one-parameter distribution function weighted with the Onsager escape probability, and the mean thermalization length (r ) is extracted therefrom (see Mozumder, 1974 ... 

An alternative method to make PAEs is the acyclic diyne metathesis (ADIMET) shown in Scheme 2. It is the reaction of a dipropynylarene with Mo(CO)6 and 4-chlorophenol or a similarly acidic phenol. The reaction is performed at elevated temperatures (130-150 °C) and works well for almost any hydrocarbon monomer. The reaction mixture probably forms a Schrock-type molybdenum carbyne intermediate as the active catalyst. Table 5 shows PAEs that have been prepared utilizing ADIMET with these in situ catalysts . Functional groups (with the exception of double bonds) are not well tolerated, but dialkyl PPEs are obtained with a high degree of polymerization. The progress in this field has been documented in several reviews (Table 1, entries 2-4). Recently, a second generation of ADIMET catalyst has been developed that allows... 

Oxidative functionalization of aliphatic and aromatic hydrocarbons is a somewhat difficult chemical transformation, in particular when a suitable degree of chemoselectivity is required. Until the last decades of the last century, metal-catalyzed functionalization of hydrocarbons with peroxides were basically limited to Fenton and Fenton-like systems ". 

Hence, in co-oxidations of hydrocarbons at constant rate of initiation in the presence of sufficient oxygen, it will be easy to depress oxidation rates of the relatively few hydrocarbons with slow termination constants, but otherwise oxidation rates will not differ much from a linear function of composition. When rates of chain initiation are not known or controlled, other relations may appear. 

A comparable functionalization of remote centers was achieved by Breslow and Winnik, in which photolysis of hydrocarbons with a benzophenone moiety attached by a tether of suitable length (51) resulted in abstraction of hydrogen by the excited benzophenone from the hydrocarbon chain. This achieved functionalization of the hydrocarbon chain (equation 80). 

With all of the hydrocarbons except amyldiphenyl, phytotoxicity appeared to be a direct function of concentration of the hydrocarbon—i.e., the lower the concentration, the lower the toxicity. For amyldiphenyl, however, concentrations of 30 to 50% produced more rapid injury and a greater degree of injury than did higher concentrations. The reasons are not clear for the apparently anomalous action of amyldiphenyl and for the apparent decrease in acute toxicity of hydrocarbons with increasing boiling points above about 500 F. Chemical properties alone may be responsible, but it is more likely that some physical property such as viscosity, surface tension, or size of molecule may be involved. Viscosity is probably the factor determining acute or chronic tjrpe of injury. 

Figure 16-21 shows the solubility of water in some hydrocarbon liquids as a function of temperature.12 The data are for saturation of the hydrocarbon with water at a given temperature under the equilibrium pressure of the existing water, hydrocarbon liquid, and hydrocarbon gas phases. The conditions correspond to the equilibrium line Q7C on Figure 17-2. 

Geelen especially examined several specific functions (specific refraction r, specific sound velocity u, specific volume i Id). The use of these functions together with the hydrogen content (%H) enables the structural composition of aromatic hydrocarbons to be determined. From data on homologous series of pure mono- and di-aromatic hydrocarbons36 he deduced the following equations for r, d and %H (20°C) ... 

The determination of the strength of the Lewis acids MF , has been carried out in various solvents using the conventional methods. Numerous techniques have been applied conductivity measurements, cryoscopy, aromatic hydrocarbon extraction,53,84 solubility measurements,85-87 kinetic parameters determinations,52,88,89 electroanalytical techniques (hydrogen electrode),90-93 quinones systems as pH indicators,94-97 or other electrochemical systems,98 99 IR,100,101 and acidity function (//,) determinations with UV-visible spectroscopy,8 9 14 19 102-105 or with NMR spectros-copy.20-22,44-46,106-108 Gas-phase measurements are also available.109-111 Comparison of the results obtained by different methods shows large discrepancies (Table 1.2). 

These polymers are typically prepared by reaction of sodium polysulfide with a formal. Bis(2-chloroelhy(formal) is commonly used, but some tn functional chlorinated hydrocarbon with its associated higher functionality is typically also added to promote branching. The sodium poly sulfide is usually made by the direct reaction of sodium hydroxide with sulfur at temperatures near 120 °C, as shown in reaction (9) 62... 

The first of the really successful coatings was a long-chain, saturated hydrocarbon with 18 carbons. These octadecyl- (ODS), RPi8, or Qg columns are still the most commonly used HPLC columns, primarily because of the versatility they have shown. Other packing materials have appeared with shorter or longer side-chains, and, with a variety of functional groups on the side-chains, greatly extended the possible separations that can be achieved with HPLC. 

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