Solid‐State and Gas‐Phase Structures and Energetic Properties of the Dangerous Methyl and Fluoromethyl Nitrates

Abstract

An improved synthesis of the simplest nitric acid ester, methyl nitrate, and a new synthesis of fluoromethyl nitrate use the metathesis of the corresponding iodomethanes with silver nitrate. Both compounds were identified by spectroscopy and the structures determined for in situ grown crystals by X‐ray diffraction as well as in the gas phase by electron diffraction. Fluorination leads to structures with shorter C−O and N−O bonds, has an energetically destabilizing effect and increases friction sensitivity, but decreases detonation performance.

Reagenzien für die selektive Fluormethylierung: Herausforderungen der Organofluorchemie

“…Einige Reaktionen wie die elektrophile Fluormethylierung von Kohlenstoff‐Nukleophilen sowie die Übertragung von CH 2 F auf schwache Nukleophile sind jedoch problematisch . Die Fluormethylierungsstärke von CH 2 FX kann beträchtlich erhöht werden, wenn Silberkationen vorhanden sind, die das Halogenid binden, wodurch die Fluormethylierung von schwachen Nukleophilen wie NO 3 −[23] und ClO 4 −[21b] möglich wird. Ursprünglich wurden CH 2 FI (Orr, 1963), später CH 2 FBr (Lesuisse, 1992) und CH 2 FCl (Sundermeyer, 1985) für die Fluormethylierung einer großen Substratanzahl verwendet .…”

Probing the Reaction Mechanisms of 3,5-Difluoro-2,4,6-Trinitroanisole (DFTNAN) through a Comparative Study with Trinitroanisole (TNAN)

“…It is unexpected that the thermal decomposition temperatures of DFTNAN is 55 °C lower than that of TNAN since fluorinated compounds usually show considerably higher thermal stability and lower sensitivities due to the C-F bond [ 16 , 17 ]. However, in Reichel’s work [ 18 ], fluorination leads to an energetically destabilizing effect of methyl nitrate and its fluorinated derivatives, which is caused by the shorter C-O and N-O bonds in molecular structures.…”

Fluoromethyl-2,4,6-trinitrophenylsulfonate: A New Electrophilic Monofluoromethylating Reagent

“…Fluoromethyl sulfonate 4 crystallizes in orthorhombic space group Pca 2 1 with two crystallographically independent molecules in the unit cell. The C–O distances to the CH 2 F group are 1.438(6) and 1.436(6) Å, in the same range as reported for fluoromethyl nitrate and significantly longer than that observed in structurally characterized compounds with O- and N-bonded CH 2 F groups (1.302–1.397 Å) . The C–F distances within the CH 2 F group are 1.355(5) and 1.359(5) Å, slightly shorter than that reported for the same compounds (1.372–1.399 Å) .…”

“…The C–O distances to the CH 2 F group are 1.438(6) and 1.436(6) Å, in the same range as reported for fluoromethyl nitrate and significantly longer than that observed in structurally characterized compounds with O- and N-bonded CH 2 F groups (1.302–1.397 Å) . The C–F distances within the CH 2 F group are 1.355(5) and 1.359(5) Å, slightly shorter than that reported for the same compounds (1.372–1.399 Å) . Both anticipate a fluoromethylation activity for new reagent 4 .…”