Computational Study of Monosubstituted Azo(tetrazolepentazolium)-Based Ionic Dimers

Abstract

The structures of monosubstituted azo(tetrazolepentazolium) cations (N11CHR(+)), oxygen-rich anions such as N(NO2)2(-), NO3(-), and ClO4(-), and the corresponding ion pairs are investigated using ab initio quantum chemistry calculations. The substituents (R) used are H, F, CH3, CN, NH2, OH, OCH3, N3, NF2, and C2H3. The stability of the protonated cation is explored by examining the decomposition pathway of the protonated cation (N11CH2(+)) to yield molecular N2 fragments. The heats of formation of these cations, which are based on isodesmic (bond type conserving) reactions, are dependent on the nature of the substituents. Ionic dimer structures are obtained, but side reactions including proton transfer, binding, and hydrogen bonding are observed in the gas phase. Implicit solvation studies are performed to determine the solution properties of the ion pairs.

Heats of formation and thermal stability of substituted 1,1′‐Azobis(tetrazole) compounds with an extended nitrogen chain

“…The calculated heats of formation will be used to quantify the energy content of these compounds. Previous studies have measured the contributions of additional nitrogen atoms to the calculated heats of formation for a few azole cations . The results show an increase of about 31 kcal/mol per nitrogen atom added in the cations triazolium, tetrazolium, and pentazolium.…”

“…The amino group (NH 2 ) is also a strong EDG but the compound only produced a small decrease in the predicted enthalpy of formation (265.9 kcal/mol). As has been stated in previous studies, additional nitrogen atoms tend to have a significant effect on the observed heats of formation and this is what is observed in this case. The contribution from the added nitrogen atom seems to counteract the expected lowering from the highly activating NH 2 group.…”

“…Previous studies have measured the contributions of additional nitrogen atoms to the calculated heats of formation for a few azole cations. [40][41][42][43] The results show an increase of about 31 kcal/mol per nitrogen atom added in the FIGURE 1 Relative energies (in kcal/mol) of the trans and cis rotamers of the unsubstituted N 10 molecule. The interconversion involves the formation of a twisted transition state.…”

Selection of an Appropriate Basis Set for Accurate Description of Binding Energy: A First Principles Study

“…Binding energies of dimers and molecules have been intensively studied both experimentally and theoretically [52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68]. To mention some of these studies, Deible et al studied the binding energy of the beryllium dimer using Quantum Monte Carlo method [64] So we have investigated the effect of different basis sets on binding energies and reported our results at CCSD(T) level.…”

Macrocycle as a “Container” for Dinitramide Salts

“…Ammonium dinitramide (ADN) holds promise as a component of green energy production [ 1 , 2 , 3 , 4 ]. Despite dinitramic acid (DNA) salts being abundantly known and well-studied, the need for the synthesis of new compounds is persistent at present as well, which is most notably due to the high content of oxygen per unit weight and environmental safety of both the product itself, its combustion products, and production technology [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. However, ADN is not free of some drawbacks that hinder its application as the component of rocket propellants.…”