Key indicators: single-crystal X-ray study; T = 90 K; mean (C-C) = 0.003 Å; R factor = 0.058; wR factor = 0.166; data-to-parameter ratio = 17.2.The title compound, (4-EtC 6 H 4 ) 2 C C C C C C(4-EtC 6 H 4 ) 2 or C 38 H 36 , was prepared from 1,1,6,6-tetrakis(4ethylphenyl)-2,4-hexadiyne-1,6-diol by reduction with SnCl 2 in an acidic medium. The molecule has a centre of symmetry at the mid-point of the cumulative double bonds, in which longer and shorter bonds alternate.