Long chain compounds

Method 2. Place a 3 0 g. sample of the mixture of amines in a flask, add 6g. (4-5 ml.) of benzenesulphonyl chloride (or 6 g. of p-toluenesulphonyl chloride) and 100 ml. of a 5 per cent, solution of sodium hydroxide. Stopper the flask and shake vigorously until the odour of the acid chloride has disappeared open the flask occasionally to release the pressure developed by the heat of the reaction. AUow the mixture to cool, and dissolve any insoluble material in 60-75 ml. of ether. If a solid insoluble in both the aqueous and ether layer appears at this point (it is probably the sparingly soluble salt of a primary amine, e.g., a long chain compound of the type CjH5(CH2) NHj), add 25 ml. of water and shake if it does not dissolve, filter it off. Separate the ether and aqueous layers. The ether layer will contain the unchanged tertiary amine and the sulphonamide of the secondary amine. Acidify the alkaline aqueous layer with dilute hydrochloric acid, filter off the sulphonamide of the primary amine, and recrystaUise it from dilute alcohol. Extract the ether layer with sufficient 5 per cent, hydrochloric acid to remove all the tertiary amine present. Evaporate the ether to obtain the sulphonamide of the secondary amine recrystaUise it from alcohol or dilute alcohol. FinaUy, render the hydrochloric acid extract alkaline by the addition of dilute sodium hydroxide solution, and isolate the tertiary amine. 

Surfactants are long-chain compounds containing a hydrophobic tail and an ionic head. In polar solvents the surfactants arrange themselves in a spherical structure known as a micelle in which the hydrophobic tails form the... 

Because of the atoms freedom to rotate about single bonds, a chain of carbon atoms can achieve various positions in space. On one extreme is the zig-zag extended chain and on the other is a coil. Such spatial structures become particularly important in determining properties of very long chained compounds known as polymers (Chapter 5). 

Knob (southern Canterbury Administrative Region see Fig. 2.11) and cycloartenol methyl ether [58] was found in plants from Clarke River, whereas four other collections failed to yield any TMEs. Similarly, populations of C. rigida (Raoul) Zotov from eastern South Island do not synthesize TMEs, whereas those from western South Island were shown to accumulate p-amyrin methyl ether [59]. An additional difference between populations from these two sites lies in the capacity of the former to produce short-chain wax components, as opposed to long-chain compounds from the latter (Cowlishaw et al., 1983). Different chemodemes were also described for C. cheesemanii (Hackel ex Cheesem.) Zotov plants from North Island exhibited lupeol methyl ether as the dominant compound along with lesser amounts of arun-doin and two unidentified compounds, whereas populations from the South Island had arundoin as the major compound with lesser amounts of lupeol methyl ether. 

A very nice example of F6rster-type energy transfer has been provided by Stryer and Haugland,<45) who studied a series of long-chain compounds (dansyl-(L-prolyl) -a-naphthyl) ... 

Yano, I. Analysis of bacterial metabolites and components by computerized GC/MS system—From shorter chain acids to very long-chain compounds up to C80. Rapid Meth. Autom. Microbiol. Immunol. (4th Int. Symp.) 1985,239-247. 

In specific cases, when long chain compounds such as esters and TAGs have survived and have not yet been hydrolysed or oxidised, it may be useful to carry out soft ionisation techniques in order to fully characterise the structure of these biomarkers by direct infusion into an electrospray source after adapted purification treatments. 

In contrast to direct mass spectrometry used in the El mode, ESI often requires specific pretreatments of the samples to purify the components of interest, to increase their yield of ionisation and consequently to improve selectivity and sensitivity. It is thus not a preliminary step of analysis but a method that forms part of an analytical strategy that allows the presence of well preserved high molecular long chain compounds to be shown before their fine characterisation by ESI techniques (Regert et al., 2003a Mirabaud, 2007 Mirabaud et al., 2007). 

Noteworthy is that no recourse is made to adjustable parameters. Semiyen (1976) in his review lists a sizeable number of systems where a fair to good agreement is found between observed and calculated values of Kx for sufficiently long-chain compounds. On the other hand, experimental ATx-values for the shorter chains deviate significantly from the calculated ones, the deviations being negative for chains of intermediate size and positive for the shortest ones. 

Huggins, M. L., Some properties of solutions of long-chain compounds, J. Phys. Chem., 46, 151-158 (1942). 

When the alkylating agent is insoluble in liquid ammonia, as in the case of long-chain compounds, an organic solvent is added to the sodium telluride residue after evaporation of the ammonia. Some cyclic and steroidal tellurides have been prepared from sodium telluride in ethanol and the appropriate dihalides. ... 

Chapman, D. The 720 cm 1 band in the infrared spectra of crystalline long-chain compounds. J. chem. Soc. 1957, 4489—4491. 

Huggins, M. L. The entropy of long chain compounds in the gaseous state. J. Chem. Phys- 8, 181-187 (1940). 

The emulsifiers are generally long chain compounds with polar groups, such as soaps of various kinds, long chain sulphonic acids and alkyl sulphates. The function of an emulsifier is to lower the interfacial tension between the dispersed phase and the dispersion medium so as to facilitate the mixing of the two liquids. 

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