Alkylated benzenes and

Aromatic. Aromatic feedstreams (C-8, C-9, C-10) derived from the steam cracking of petroleum distillates are composed of styrene, iadene, vinyltoluenes (eg, meta- and i ra-methylstyrene), and their respective alkylated analogues. A typical aromatic feedstream might contain 50% reactive olefins with the remainder being alkylated benzenes and higher aromatics. 

Alkylation. Benzene and phenol feedstocks are readily alkylated under Friedel-Crafts conditions to prepare extensive families of alkylated aromatics. These materials generally are intermediates in the production of surfactants or detergents such as linear alkylbenzenesulfonate (LABS) and alkylphenolethoxylate (APE). Other uses include the production of antioxidants, plasticizers, and lube additives. 

Structure—Performance Characteristics of Surfactants in Contact with Alkanes, Alkyl Benzenes, and Stock Tank Oils... 

E. L. Shock (1990) provides a different interpretation of these results he criticizes that the redox state of the reaction mixture was not checked in the Miller/Bada experiments. Shock also states that simple thermodynamic calculations show that the Miller/Bada theory does not stand up. To use terms like instability and decomposition is not correct when chemical compounds (here amino acids) are present in aqueous solution under extreme conditions and are aiming at a metastable equilibrium. Shock considers that oxidized and metastable carbon and nitrogen compounds are of greater importance in hydrothermal systems than are reduced compounds. In the interior of the Earth, CO2 and N2 are in stable redox equilibrium with substances such as amino acids and carboxylic acids, while reduced compounds such as CH4 and NH3 are not. The explanation lies in the oxidation state of the lithosphere. Shock considers the two mineral systems FMQ and PPM discussed above as particularly important for the system seawater/basalt rock. The FMQ system acts as a buffer in the oceanic crust. At depths of around 1.3 km, the PPM system probably becomes active, i.e., N2 and CO2 are the dominant species in stable equilibrium conditions at temperatures above 548 K. When the temperature of hydrothermal solutions falls (below about 548 K), they probably pass through a stability field in which CH4 and NII3 predominate. If kinetic factors block the achievement of equilibrium, metastable compounds such as alkanes, carboxylic acids, alkyl benzenes and amino acids are formed between 423 and 293 K. 

These conclusions were not applicable when sediment was the source of hydrocarbons. McCain et al. (5) studied the bioavailability of petroleum in sediment to English sole (Parophrys vetu-lus). Sediments rich in alkylated and non-alkylated benzenes and naphthalenes, together with fluorene and phenanthrene, were employed. After 11 days of exposure, samples of skin, muscle, and liver were examined. Fluorene and phenanthrene were not accumulated in the test fish however, significant concentrations of 1-methyl naphthalene, 2-methyl naphthalene, 2,6-dimethyl naphthalene and 1,2,3,4-tetramethylbenzene, were found in skin and liver (Table II) 1-methyl naphthalene and 2-methyl naphthalene were the major components of muscle. In each tissue examined, 1-methyl-naphthalene was the major component 1,2,3,4-tetramethylbenzene occurred in relatively low concentrations in skin and muscle in comparison to naphthalenes containing one and two alkyl groups. 

Tab. 12 Indirect electrooxidation of alkyl benzenes and hydrocarbons with cerium mediators... 

Wolf MA, Rowe VK, McCollister DD, et al Toxicological studies of certain alkylated benzenes and benzene. AMA Arch Ind Health 14 387-398, 1956... 

Figure 8.1. Relation of solubility parameters (solpars or Hildebrand 8 values) and carbon numbers in various homologous series of solvents. (4) Normal alkanes, (B) normal chloroalkanes, (C) methyl esters, (D) alkyl formates and acetates, (E) methyl ketones, (F) alkyl nitriles, ) normal alkanols, (H) alkyl benzenes, and (I) dialkyl phthalates.

Dimethyl-chloronium and -bromonium ions give similar methylation results and are quite reactive even at temperatures as low as —50°C. The dimethyliodonium ion is less reactive and alkylates benzene and toluene in SO2CIF solution only when allowed to react (if necessary under pressure) at or above 0°C. 

Melting point vs. chain length for a and (3 alkylnaphthalene, alkyl benzene, and paraffins. 

TABLE 2. Isomer ratio (%) in the nitration of alkyl-benzenes and Q)0 fullerene solubility in alkyl-benzenes [34]... 

Calsoft Series Alkyl benzene and alpha olefin sulphonates... 

Though FAME has limited oxidation stability, they remain a valid alternative for diesel. Conventional diesel fuel has a boiling range of 180-340 °C, with a composition of n-alkanes, cycloalkanes, alkyl benzenes, and polyaromatic compounds. Fossil diesels have a CN in the range 40-100. FAME has properties that are close to all these basic diesel properties. FAME can also easily blend with fossil diesel at any level due to their similar solvent behavior the viscosity of fossil diesel and biodiesel are also in the same range. 

Figure 2.7 contains plots of repetitive injection GC/MS chromatographic peak areas (integrated total ion current) as a function of sample temperature for benzene and styrene as well as selected products representing alkyl aromatics (ethyl benzene), indanes (methyl indane) and indenes (indene) evolved from PS-catalyst samples. The plots show that benzene is by far the most abundant volatile product. All of the PS-catalyst samples produce alkyl benzenes and indanes, however samples containing HZSM-5 catalyst generate significantly lower relative yields of these products. 

Figure 11.5 shows that the functional group compositional analysis of the pyrolysis oil/waxes derived from the fixed-bed pyrolysis of PVC, PS and PET is very different from the polyalkene plastic pyrolysis oil/waxes. The spectra of the PVC pyrolysis oil/wax shows that the characteristic peaks of alkanes and alkenes are present as described for the polyalkene plastics. Since the PVC plastic polymer is based on a similar backbone structure to the polyalkene plastics, a similar degradation product oil/wax composition may be expected. However, the spectra for PVC in Figure 11.5 show that there are additional peaks in the region of 675-900 cm and 1575-1625 cm The presence of these peaks indicates the presence of mono-aromatic, polycyclic aromatic and substituted aromatic groups. Benzene has been identified as a major constituent in oils derived from the pyrolysis of PVC whilst other aromatic compounds identified included alkylated benzenes and naphthalene and other polycyclic aromatic hydrocarbons [19, 32, 39]... 

A similar observation has been made in the study of the energy-dependent transfer from aromatic sulfides to various acceptor radical cations as derived from benzene, alkyl benzenes and biphenyl. Whereas the reaction in the case of the first two cations... 

A brief review and reassessment of data on the photophysics of benzene has been presented by Pereira. Evidence for the l E2g valence state has been obtained by u.v. two-photon spectroscopy.Slow electron impact excites fluorescence in thin films of benzene at 77 K as well as emission from isomers." The fluorescence yields and quenching by chloroform of alkyl-benzenes and 1-methylnaphthalene after excitation into Si, Sz, and S3 states and after photoionization have been measured. The channel-three process has been reconsidered in terms of the effects of local modes and Morse oscillator potentials. Excited-state dipole moments of some monosubstituted benzenes have been estimated from solvent effects on electronic absorption spectra, Structural imperfections influence the photochemistry of durene in crystals at low temperatures. Relaxation time studies on excited oxido-substituted p-oligophenylenes have been made by fluorescence depolarization... 

Nitro-alkyl Benzenes.—-Isomeric with nitro toluene we have nitro-methyl benzene, CeHs—CH2NO2, which belongs to the group of nitro substitution products in which nitration takes place in the paraffin side-chain and not in the benzene ring. It must be formed, therefore, not by direct nitration, but by reaction between a halogen-alkyl benzene and silver nitrite. 

By combining our knowledge of alcohols with what we know about alkyl-benzenes and aromatic substitution, we can extend our syntheses to include aromatic alcohols. For example ... 

Uses. Tetramethylene sulfone has high solvent power for aromatics and has been used extensively by Olah and co-workers for Friedel-Crafts type nitrations and for studies of the mechanism of nitronium tetrafluoroborate nitration of alkyl-benzenes and halobenzenes in homogeneous solution. It is a superior solvent for quaternization of tertiary amines with alkyl halides, since it has a high dielectric constant and does not enter into side reactions observed with nitrobenzene and dimethylformamide. For example in the synthesis of the acridizinium salt (3), Bradsher and Parham effected quaternization of (1) with benzyl bromide in tetramethylene sulfone at room temperature in excellent yield. Several other salts analagous to (2) were obtained in good yield and in crystalline form with use of tetramethylene sulfone, whereas with other solvents the products were colored... 

In principle, there should not be surface diffusion for nonretained compoimds. On the other hand, the mobile phase is adsorbed at the liquid-solid interface and its properties in this monolayer cannot be the same as those of the bulk solvent. This explains why the limit of the sruface diffusion coefficient when the equilibrium constant tends toward zero is smaller than Dm (Eq. 5.81). Finally, Miyabe has shown that there is a linear free energy relationship between the equilibrium constant of retention and the sruface diffusion coefficient [119]. This has led to the development of a procedure for the derivation of a first approximation of the sruface diffusion coefficient. However, data are available only for alkyl-benzenes and alkyl-phenols at this time. 

---