Flash Photolysis of 2,4,6‐Trinitrotoluene Solutions

Abstract

Flash photolysis of 2,4,6‐trinitrotoluene solutions (TNT) indicates a photochemically induced isomerization leading to the aci‐quinoid isomer with an absorption maximum at 460 nm in nonpolar solvents, or the conjugate base of the aci‐quinoid isomer with absorption maxima at 500, 540, and 630 nm in polar solvents. Both species, the quinoid isomer and the conjugate base, have transient existence and their identification was based on detailed spectroscopic and kinetic studies presented here. The magnitude of the negative charge on the transient conjugate base was determined with salt effect experiments and found to be equal to unity.

Photochemical Reaction Mechanisms of 2-Nitrobenzyl Compounds in Solution, I. 2-Nitrotoluene: Thermodynamic and Kinetic Parameters of theaci-Nitro Tautomer

“…In the absence of substituents at the benzylic position, the yellow aci-nitro compounds revert to the starting materials. Examples of such photochromic [5] behavior are 2-nitrotoluene (1) [6], 2,4-and 2,6-dinitrotoluene [7] [8], 2,4,6-trinitrotoluene [9], and 2-(2',4'-dinitrobenzyl)pyridine [10] [11]. In the Scheme 1 presence of a leaving group at the benzylic position, the aci-tautomers form 2-nitrosobenzyl compounds, thereby deprotecting the leaving group.…”

Triplet excited states of nitronaphthalenes. III. 1,4‐dinitronaphthalene

“…Since the proton is known to attach itself to one of the oxygens of the nitrogroup [4,10,21,22], the low reactivity of the triplet 1,4-DN02N toward the proton seems to indicate that the oxygen of the nitro group becomes electron deficient during electronic excitation, which in turn is consistent with the assignment of the 1,4-DNOzN triplet to a predominantly n -+ x* state and furthermore with the high reactivity of this state toward the electron [23,24].…”

Photochemical decomposition of 2,4,6-trinitrotoluene and related compounds in ethers

“…Two specific kinds of solvents can be identified: those with hydrogen atoms which apparently are abstractable by excited nitroaromatics such as ethers or alcohols,1-14 and those which apparently are inert during at least the early phases of the photochemical reaction. [15][16][17][18][19][20][21][22][23][24] Lagercrantz and Yhland2,3 and Ward1 11were the first to use electron paramagnetic resonance (EPR) to observe production of radicals from photochemical reaction of nitrobenzene in ethers. Ward's interpretation of the spectra was later corrected by Cowley and Sutcliffe8,10 and Janzen and Gerlock.…”