Aspects of conformation in ring-substituted 2,4,6-trinitroanilines deduced from absorption spectra

Abstract

From the relative absorption intensities of two characteristic bands in the ultraviolet spectra of 2.4.6-trinitroaniline and its derivatives, it is possible to estimate angles of twist from planarity of the 2-, 4-, and 6-nitro-substituents.

Kinetics of the Nucleophilic Substitution Reactions of Methyl 2,4-Dichloro-3,5-Dinitrobenzoate with Piperidine, Piperazine, Morpholine and Thiomorpholine in Methanol and Benzene

“…Whereas 1 H NMR and IR spectroscopic data do not indicate which C-2 or C-4 is attacked, the UV bands at l = 302 and 362 nm for 2-5 are comparable to those of 2,4,6-trinitroaniline. 20 This indicates that the electronic transitions between C(2)-C(3) and C(2)-C(5) take place respectively, 21 i.e. electronic transitions between the lone pair on nitrogen at C-2 and the nitro groups at C-3 and C-5, Equation (2).…”

Rate Increase in Consecutive Nucleophilic Aromatic Substitution Reactions of Trichlorotrinitrobenzene: The Synthesis of 1-(Alkylamino)-3,5-dichloro-2,4,6-trinitrobenzenes

“…The twist of substituents in 2a had been estimated on the basis of its UV-vis spectrum. 28 On the basis of the X-ray structural data available then, the authors assumed a twist angle of 65-70°with respect to the plane through the benzene ring for the nitro group in the 4-position. They discussed several possibilities for the twist of the remaining substituents and arrived at a "best guess" of twist angles of 40-45°for the nitro groups in the 2,6 positions.…”

“…In accordance with this hypothesis, hydrogen positions could not be located in contrast to the usual behavior in hydrogen bonding between nitro and amino groups in the ortho positions. The twist of substituents in 2a had been estimated on the basis of its UV−vis spectrum . On the basis of the X-ray structural data available then, the authors assumed a twist angle of 65−70° with respect to the plane through the benzene ring for the nitro group in the 4-position.…”

Ultraviolet spectrometry

“…Thirty-four di-, tri-, and tetranucleotideswere examined at pH 1, 7, and 12 and the spectrophotometric constants calculated by computer (372). The angle of twist of substituents from planarity has been estimated from spectral data for the nitro groups on 2,4,6-trinitroaniline (208) and for a phenyl or naphthyl group in hydrocarbons (371). Spectral shifts in the presence of certain additives were used to locate the hydroxyl groups on xanthones (247).…”