Determination of the structure of 2(benzene-1,3,5-tricarboxylic acid)-1.5(pyrene)-2(methanol) and comparison with that of 2(benzene-1,3,5-tricarboxylic acid)-pyrene-2(ethanol).
The structure of the title methanol complex (P1;, Z = 2) has been determined and compared with that of the title ethanol complex (C2/c, Z = 8) using published data. Both complexes have layer structures, the (essentially planar) layers being constructed from rings of six TMA molecules, hydrogen bonded through four 'carboxyl dimers' and two 'interrupted dimers', where methanol (ethanol) is included in the R4(4)(12) (graph set) ring. The packing of the layers differs in the two complexes, leading to different three-dimensional structures. In the methanol complex, one pyrene molecule is located within the layer and the other, at a centre of symmetry, between the layers in one type of interlayer space, while the methyls of methanol protrude into the other type of interlayer space. In the ethanol complex, the superpositioning of the layers is such that two types of stack are formed; one of these is mixed, containing pyrene and one of the independent TMA molecules in alternating sequence, while the other stack contains only the second type of TMA. Spectroscopic study is needed to establish whether the partial mixed stack arrangement in the crystalline ethanol complex implies donor-acceptor interaction.
Herbstein
F H
FH
Department of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel. chr03fh@tx.technion.ac.il
Kapon
M
M
Shteiman
V
V