The pseudo-inversion symmetry of 9,90′ (1,3,4-oxadiazole-2,5-diyldi(1,1′-biphenyl)-2′,4- diyl)bis[9H-carbazole] in the light of OD theory

Abstract

The pseudo-inversion symmetry of 9,9 0 -(1,3,4-oxadiazole-2,5-diyldi(1,1 0 -biphenyl)-2 0 ,4-diyl)bis [9H-carbazole] in the light of OD theory Abstract: The crystal structure of 9,9 0 -(1,3,4-oxadiazole-2,5-diyldi(1,1 0 -biphenyl)-2 0 ,4-diyl)bis[9H-carbazole] [Pna2 1 , Z ¼ 4, a ¼ 17:9874ð4Þ Å, b ¼ 9:2989ð8Þ Å, c ¼ 21:5822ð9Þ Å, R obs ¼ 0:0395, 9239 F data, 496 parameters] features a pseudo-centre of inversion strictly valid only for isolated layers of the structure. It is an order-disorder (OD) structure made up of one kind of non-polar layers composed of (I) molecules connected to polar layer pairs. The major polytype is of a maximum degree of order. The magnitude of the intrinsic translation vectors of the glides and screws relating adjacent layers is a convenient quantification of the deviation from perfect centrosymmetry.