Structure of the Head-to-tail Cis-anti-cis Photodimer of 2-methylbenzobthiophene 1,1-dioxide

摘要

r-1,c-2,t-3,t-4-Di(2',3'-benzothiophene 1,1-dioxide)-1,3-dimethylcyclobutane (alternative name: 5a,10a-dimethyldibenzo[d:d']cyclobuta[1,2-b:4,3-b']-dithiophene 5,5,10,10-tetraoxide), C18H16O4S2, M(r) = 360.4, monoclinic, P2(1)/a, a = 6.918 (1), b = 12.270 (1), c = 9.283 (1) angstrom, beta = 104.13 (2)-degrees, V = 764.1 (2) angstrom 3, Z = 2, D(x) = 1.56 Mg m-3, lambda(Cu K-alpha) = 1.54178 angstrom, mu = 3.29 mm-1, F(000) = 376, T = 293 K, R = 0.051 for 1357 observed reflections. The molecular structure shows no significant differences in bond lengths and bond angles between the two benzo[b]thiophene groups. A crystallographic centre of symmetry coincides with the cyclobutane ring and this dimer possesses a cis-anti-cis structure.