Crystal and molecular structure of 2,5-dimethyl-3,4-di(2-propyl)-hex-3-ene (tetraisopropylethylene) at 170 K.

X-ray analysis of tetraisopropylethylene has revealed that the structure is disordered since there are two molecules (population factors 0.85 and 0.15 respectively) rotated by 90° with respect to each other around the normal to the ethylenic plane through the origin, which is the midpoint of the CC double bond. The ethylenic skeleton is planar and bond angles and distances are in the normal range.