Alkanes, properties

Perdih, A. (2000a) On topological indices indicating branching. Part 1. The principal component analysis of alkane properties and indices. Acta Chim. Sloven., 47, 231-259. 

Toropov, A.A. and Toropova, A.P. (2003) QSPR modeling of alkanes properties based on graph of atomic orbitals./. Mol. Struct. (Theochem),6i7,1-10. 

In this section a selection of alkane properties will be presented along with QSAR models based on topological methods. For more examples see Rouvray , Kier and Hall and Trinajstic. ... 

The selection of QSAR models presented above gives a general indication of the types of relationships which can be developed and of the high quality obtained with the use of topological indices. This chapter has dealt with the most widely used indices, but references given in the early sections discuss other methods and indices. Although much more effort has been applied to heteroatom molecules, much more remains to be done on alkane properties. The combination of the chi ""Xt) indices, the kappa indices and the electrotopological (Si) indices provide a powerful set of tools in the development of QSARs. 

Definition Sodium salt of secondary sulfonated C9-22 alkanes Properties Anionic... 

References [12-23, 30-39] are useful sourees of olefin and alkane properties. Properties of 1-olefins having two to forty carbons were published in 1953 [14] and 1959 [13]. Many of these properties are given in Tables 1-5. n-Alkane densities [36, 37, 40] and melting points (Cl to Coo) (amorphous polymethylene) [23, 31] and... 

The method used most in the present work to estimate amorphous polyethylene properties consisted in using oligomer (ra-alkane) properties to calculate limiting properties (Pcx>, properties of an infinite-length homolog) sueh limiting properties resemble the corresponding properties of amorphous, linear polyethylene (or amorphous polymethylene) (Table 11). 

The use of n-alkane properties (with suitable equations) to estimate amorphous polyethylene properties has the advantage the ra-alkanes (unlike the polyolefins) ean be prepared pure, and accurate properties can be determined. The use of n-alkane data has the limitations, however, that some properties (e.g., boiling points) are irrelevant for polymers and some polymer properties (e.g., tensile strength) are lacking in the lower alkanes. This method treats the main backbone polymer chain as the functional group and the pendant alkyl groups or repeat units as the homolog chain for correlation purposes. 

A second method of estimating poly(l-olefin) properties consisted in creating equations correlating n-alkane properties with -alkane densities, and then using the equations with poly(l-olefin) densities to estimate poly(l-olefin) properties. 

Equations (4), (5), (25) and (26) are among those [46, 64-65] that can be used conveniently to estimate limiting properties (Pco) from n-alkane properties, and also to correlate amorphous poly (1-olefin) properties with the molecular weight or number of carbons in the repeat units ... 

Some of the equations developed to correlate -alkane properties with homolog chain length and to estimate limiting and amorphous polyethylene properties are given below. 

Alkane properties Alkanes are nonpolar compounds with relatively low melting and boiling points compared to polar molecules of similar mass. Alkanes have low solubilities in water. They also have low reactivities, but they readily undergo combustion in oxygen and are commonly used as fuels. Alkanes are saturated hydrocarbons that contain only single bonds. In the next section, you will examine unsaturated hydrocarbons, which have at least one double or triple bond between carbon atoms. 

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