Gauche conformations higher alkanes

Higher alkanes having unbranched carbon chains are like butane most stable m then-all anti conformations The energy difference between gauche and anti conformations is similar to that of butane and appreciable quantities of the gauche conformation are pres ent m liquid alkanes at 25°C In depicting the conformations of higher alkanes it is often more helpful to look at them from the side rather than end on as m a Newman projec tion Viewed from this perspective the most stable conformations of pentane and hexane... 

The higher alkanes resemble butane in their preference for anti and gauche conforma-Conformations tions about the carbon-carbon bonds. The lowest-energy conformation for any straight-Of Hi Cl her Alkanes c la n alkane is the one with all the internal carbon-carbon bonds in their anti a conformations. These anti conformations give the chain a zigzag shape. At room... 

In crystalline materials, with the alkane chains tightly packed and in an all-//cum conformation, the asymmetric stretch of the methylene groups va(CH2) shows at 2918 cm-1, whereas in liquid state, with disordered orientation of alkane chains and high concentration of gauche interactions, the position of this peak is shifted towards higher frequencies (2921-2924 cm-1). 

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