抄録
The structure of 4,4′-bi(3-(1-methylethoxy)-3-cyclobutene-1,2-dione) was determined by X-ray crystallography. A symmetry operation (-x+1, -y+1, -z+2) generated the whole molecule. The compound crystallised in a monoclinic system and was characterised as follows: P21/c, a = 5.6929(5)Å, b = 13.3409(13)Å, c = 9.5865(9)Å, β = 106.414(2)°, Z = 2, V = 698.41(11)Å3. The crystal structure was solved by a direct method and refined by full-matrix least-squares on F2 to obtain final values of R1 = 0.0423 and wR2 = 0.00894. The carbon-carbon (C-C) bond lengths suggested that not only the cyclic-linker C-C bond, but also adjacent C-C bonds, are involved in two kinds of delocalised electron systems.
