Structure and Bonding in 2‐Diazo‐4,6‐Dinitrophenol (DDNP)

Abstract

The structure and bonding in 2-diazo-4,6-dinitrophenol (DDNP) is discussed on the basis of quantitative molecular orbital (MO) calculations at the density functional theory (DFT) level using the natural bond orbital analysis (NBO). Qualitative valence bond theory (VB) was used to generate an increased VB structure for DDNP. The increased-valence structure is better in accordance with the computed and observed (X-ray) geometry than is the NBO analysis.

New Energetic Materials featuring Tetrazoles and Nitramines – Synthesis, Characterization and Properties

“…The most characteristic absorptions, however, derive from the nitro groups. Compounds 8, 9 and 15 exhibit one set of absorptions each, which are located 4 ] + at m/z 69.1 can be observed in the spectra of 8, 9 and 12. Often, the loss of one or even two nitro groups is observed, which exemplarily is discussed for compound 11:…”

“…Of particular interest are high-nitrogen compounds (e.g. tetrazoles) in combination with energetic substituents such as nitro groups (R-NO 2 ) [3,4], nitrate esters (R-O-NO 2 ) [5], azide groups (R-N 3 ) [6] or nitramine functionalities (R 2 N-NO 2 ) [7,8]. Also the formation of tetrazolium salts with oxygen rich counter anions such as NO 3 - [9,10] or N(NO 2 ) 2 - [11,12] are in the focus of our research, since these compounds have balanced oxygen contents.…”

Theoretical studies on 2-diazo-4,6-dinitrophenol derivatives aimed at finding superior propellants

“…Table 1 presents the Wiberg bond indices (WBI) and bond lengths for the DDNP molecule. For comparison, the computed and experimental results of Holl et al [38] are also listed in the table.…”

“…They should be safe, stable and reliable enough to detonate under specific conditions [40]. Sensitivity refers to the propellant's [38] stability to various external stimuli such as heat, impact, shock, or an electrical spark [41]. Predicting the sensitivity, which can be done by examining the molecular structure, is a very important step when developing new energetic materials.…”

Green Primary Explosives

“…Structurally, DDNP is a picric acid derivative and is synthesized from picramate in acidic solution with a nitrite salt (Scheme 5.6). Its exact structure has been the subject of debate over the years, with some early studies depicting the direct bonding of the diazo group with the phenolic oxygen to form a fuzed, bicyclic ring system [2]; even after the crystal structure of DDNP was finally reported in 1987 [88], discrepancy still exists over the exact resonance structure [89].…”