COMPLEXES OF PYRENE WITH 2,4,6-TRINITROANISOLE. STUDIES OF ASSOCIATION IN SOLUTION AND THE CRYSTAL STRUCTURE OF THE 1:1 COMPLEX

Article abstract of DOI:10.1016/S0040-4020(01)91810-1

Cyclohexane solutions of 2,4,6-trinitroanisole (A) containing excess pyrene (D) can be described in terms of a double equilibrium involving complexes DA and D2A.Formation constants for these complexes from A and from DA respectively from three independent experiments are in good agreement, the average values being K₁=9.7 kg mol^-1 and K₂=1.8 kg mol^-1 at 33.5 degC.The crystalline complex was obtained by gel diffusion.The mw (C₂₃H₁₅N₃O₇) corresponds to 1:1 stoichiometry C₁₆H₁₀, C₇H₅N₃O₇, X-ray structure data: P2₁/c, a=10.633(7), b=16.336(8), c=11.683(7) Angstroem, β=94.62(12) deg , V=2023 Angstroem, F₀₀₀=924, μ(CuKα)=8.3 cm^-1, Z=4.R=O.O91 for 1572 reflexions.The crystal contains extended stacks ADADA, parallel to (101).The pyrene molecules are disordered by rotation over two sites.The majority site has an accupancy factor of 0.544(2).The angle between te normals to the mean planes of A and D is 7.0(4) deg , allowing the nitro groups of A to twist out of the plane of the benzene ring by 41.0(1.0), 2.7(5) and 20.7(8) deg.