“…(7)(8)(9)(10)(11)(12) On the other hand, H E m s of our mixtures increase with the chain length of the n-alkane. By analogy with the a,v-dichloroalkanes (13) and the a,v-dibromoalkanes (9,11) (14) {xClCH 2 Cl + (1 − x)CH 3 (CH 2 ) 5 CH 3 }, (15) and {xBrCH 2 Br + (1 − x)CH 3 (CH 2 ) 5 CH 3 } {H E m (x = 0.5) = 1620 J·mol −1 ; this work, but mixture not included} show very similar behaviour to the above for our mixtures. This behaviour may be explained by the ''proximity effect'' between the two halogen atoms {''isoproximity effect'': X(CH 2 )X or XCH 2 (CH 2 ) n-2 CH 2 X; and ''heteroproximity effect'': X(CH 2 )Y or XCH 2 (CH 2 ) n-2 CH 2 Y}.…”