Alkanes long chain

In the essential oil of St. John s Wort approx. 30 individual components were found using GC [94]. The most abundant constituents were 2-methyl-octane, a-pinene and dodecanol. Further lipophilic nonvolatile compounds such as alkanes, long-chain fatty alcohols, fatty acids and some carotenoids were also reported [2]. 

AlMepO-beta, water adsorption 09-P-14 n-Alkanes, long chain, isomerisation 26-P-23... 

The Bristol group have studied the activity coefficients of benzene and fluorobenzenes in various n-alkane long-chain hydrocarbons with the aim of testing various solution theories. The activity coefficient of benzene at 323 K varies from 0.993 in hexadecane to 0.644 in dotriacontane. The trend in the fluorobenzene systems is for the activity coefficient to increase with increasing fluorocarbon substitution. For example, in the case of n-octadecane systems at 323 K, the activity coefficient for fluorobenzene is 1.130 while for hexafluoro-benzene it is 1.945. In these cases, the temperature variation of the activity coefficients was sufficiently great to warrant the determination of the infinitely dilute excess enthalpies. 

Pablo J J, M Laso, JI Siepmann and U W Suter 1993. Continuum-Configurational Bias Monte Carlo Simulations of Long-chain Alkanes. Molecular Physics 80 55-63. 

In spite of the ene ending to its name polyethylene is much more closely related to alkanes than to alkenes It is simply a long chain of CH2 groups bearing at its ends an alkoxy group (from the initiator) or a carbon-carbon double bond... 

Chain termination. The chlorination of alkanes by rm-butyl hypochlorite is believed to follow a chain mechanism, but there is a dispute about the termination step.10 Derive the steady-state rate equation for each, making the long-chain approximation. 

The alkaline product from the wood ash was a crude solution of sodium and potassium carbonates called "lye". On boiling the vegetable oil with the lye, the soap (sodium and potassium salts of long chained fatty acids) separated from the lye due to the dispersive interactions between the of the fatty acid alkane chains and were thus, called "lyophobic". It follows that "lyophobic", from a physical chemical point of view, would be the same as "hydrophobic", and interactions between hydrophobic and lyophobic materials are dominantly dispersive. The other product of the soap making industry was glycerol which remained in the lye and was consequently, termed "lyophilic". Thus, glycerol mixes with water because of its many hydroxyl groups and is very polar and hence a "hydrophilic" or "lyophilic" substance. 

For the preparation of long-chain alkanes it proved useful to extract the electrolyte continously with a high boiling point nonpolar solvent. This way the alkanes ... 

Painted BLMs were made of a solntion of the desired phospholipid in a long-chain alkane (n-decane or hexadecane) or sqnalene [160], Again, a Teflon cnvette was separated into two compartments by a septnm with an orifice 0.8-3 mm in diameter. The orifice was... 

Their physical properties are essentially those of the alkanes. It is the unsaturated linkages that dominate the chemistry and the main reaction is one of addition (e.g. hydrogen, halogen, and hydrogen halides) across the double bond to produce saturated compounds. This reactivity is utilized in the manufacture of long-chain polymers, e.g. polyethylene and polypropylene. 

Aeckersberg F, FA Rainey, F Widdel (1998) Growth, natural relationships, cellular fatty acids and metabolic adaptation of sulfate-reducing bacteria that utilize long-chain alkanes under anoxic conditions. Arch Microbiol 170 361-369. 

Hydroxylation of long-chain carboxylic acids, amides, and alcohols—but not the esters or the corresponding alkanes—at the w-l, (0-2, and (o-3 positions by a soluble enzyme system from Bacillus megaterium (Miura and Fulco 1975 Narhi and Fulco 1986,1987). 

Caldwell ME, RM Garrett, RC Prince, JM Suflita (1998) Anaerobic biodegradation of long-chain -alkanes under sulfate-reducing conditions. Environ Sci Technol 32 2191-2195. 

Huybrechts, W., Mijoin, J., Jacobs, P.A. et al. (2003) Development of a fixed-bed continuous-flow high-throughput reactor for long-chain n-alkane hydroconversion. Appl. Catal. A Gen., 243, 1. 

Termination of the reaction by radical/radical interaction is unlikely to occur to any significant extent, until the concentration of long-chain alkane has dropped to a very low level. 

There is a much wider choice of hydrophobes. Most are based on substantially linear long-chain alkanes, either saturated or unsaturated. These were originally obtained from naturally occurring fats and oils such as castor, fish, olive, sperm, coconut and tallow oils, but these sources were later superseded by petroleum products which at that time were cheaper. More recently, not only has the price of crude oil escalated, but there has also been a growing... 

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