Conformations alkanes

Table 3.5 Energy Costs for Interactions in Alkane Conformers...

Figure 3.10 The most stable alkane conformation is the one in which all substituents are staggered and the carbon-carbon bonds are arranged anti, as shown in this model of decane.

Table 4-1 Energy costs for interactions in alkane conformers... 

Draw alkane conformations, compare their energies, and predict the most stable conformations. 

Alkane An open-chain hydrocarbon in which all carbon-carbon bonds are single bonds. The alkanes conform to general formula... 

Alkane conformations can be classified as eclipsed, staggered, anti, or gauche depending on the relative orientation of the groups on adjacent carbons. 

H-3a,4-Diazaazulenes synthesis, 4, 297 Diazabicycloalkanes anion complexes, 7, 747 conformation, 7, 737 Diazabicyclo[k. /. m]alkanes conformation, 7, 739-740 Diazabicydodecanes synthesis, 5, 315... 

J, T. Edward, P. G. Farrell, and F. Shahidi,. Phys. Chem., 82, 2310 (1978). Partial Molal Volumes of Organic Compounds in Carbon Tetrachloride. 1. Alkanes. Conformational Effects. 

The NMR spectroscopic investigations also showed that incarceration had a strong effect on the conformational preference of 89 (Fignre 9.29). Contrary to gas phase ab initio calculations, which predict trans-S9 as the lower energy conformation, the conformational equilibrium is reversed in the inner phase. Thns, confinement favors the coiled and more compact cis- over the extended trans conformation, which is consistent with the observations of coiled linear alkane conformations in self-assembled molecular capsules. ... 

Calculated Enthalpies and Strain Energies of Tetramantanes, Pentamantanes, and Corresponding Simple Alkane Conformers (kcal mole , 25°, gas)... 

Compare the energies of alkane conformations and predict the most stable conformation. 

Since their discovery in 1949 , n-alkane urea inclusion compounds (UIC) have fascinated chemists and spectroscopists alike . However, there is disagreement about the interpretation of the deuterium NMR spectra of UICs. Originally, it was believed that in these channel clathrates the alkanes exist in an a -trans conformation. Recently, it was shown that significant amounts ca 30%) near the end of the chains are present in a gauche conformation. An illustration of the possible alkane conformations based upon MM2 calculations is shown in Figure 4 . 

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