Journal Article10.1021/IC9606237
Besides N2, What Is the Most Stable Molecule Composed Only of Nitrogen Atoms?†
241
TL;DR: The increment scheme also provides estimates of the strain energies of polynitrogen compounds, e.g., tetraazatetrahedrane, octaazacubane, and N(20) (27, 294.6 kcal/mol), and is useful in searching for new high-energy-high-density materials.
read more
Abstract: Polynitrogen molecules have been studied systematically at high levels of ab initio and density functional theory (DFT). Besides N2, the thermodynamically most stable Nn molecules, located with the help of a newly developed energy increment system, are all based on pentazole units. The geometric, energetic, and magnetic criteria establish pentazole (2) and its anion (3) to be as aromatic as their isoelectronic analogues, e.g., furan, pyrrole, and the cyclopentadienyl anion. The bond lengths in 2 and 3 are equalized; both have large aromatic stabilization energies (ASE) and also substantial magnetic susceptibility exaltations (Λ). The Cs symmetric azidopentazole (14), a candidate for experimental investigation, is the lowest energy N8 isomer but is still 196.7 kcal/mol higher in energy than four N2 molecules. Octaazapentalene (12) with 10 π electrons also is aromatic. The D2d symmetric bispentazole (21) is the lowest energy N10 minimum but is 260 kcal/mol higher in energy than five N2 molecules. For strain...
read more
Chat with Paper
AI Agents for this Paper
Find similar papers on Google Scholar, PubMed and Arxiv
Write a critical review of this paper
Analyze citations of this paper to find unaddressed research gaps
Citations
All-Metal Aromaticity and Antiaromaticity
TL;DR: These new developments have shown that aromaticity and antiaromaticity in metal systems have frequently multiple nature, being o-aromatic/antiaromatic and n-Aromatic/Antiaromatic, which is not found in organic aromatic/antaromatic molecules.
556
On a Quantitative Scale for Lewis Acidity and Recent Progress in Polynitrogen Chemistry
Karl O. Christe,Karl O. Christe,David A. Dixon,Douglas McLemore,William W. Wilson,Jeffrey A. Sheehy +5 more
TL;DR: A quantitative scale for Lewis acidities based on fluoride ion affinities is discussed in this paper, which uses pF − values which represent the fluoride ion affinity in kcal/mol divided by 10.
398
Experimental Detection of Tetranitrogen
TL;DR: An examination of the geometry of N4 + and the fragmentation pattern of the 14N2 15N2 neutral molecule has revealed that the latter is characterized by an open-chain geometry with two distinct, closely bound N2 units joined by a longer weaker bond.
224
Polynitrogen compounds 1. Structure and stability of N4 and N5 systems
TL;DR: In this article, the authors summarized the results concerning the molecular and electronic structure and thermodynamic stability of polynitrogen compounds Nn, with n ranging from 4 to 60, as revealed by quantum chemical calculations published in the past 30 years, and where available, by experimental observations.
182
References
Density‐functional thermochemistry. III. The role of exact exchange
TL;DR: In this article, a semi-empirical exchange correlation functional with local spin density, gradient, and exact exchange terms was proposed. But this functional performed significantly better than previous functionals with gradient corrections only, and fits experimental atomization energies with an impressively small average absolute deviation of 2.4 kcal/mol.
A New Mixing of Hartree-Fock and Local Density-Functional Theories
TL;DR: In this article, a new coupling of Hartree-Fock theory with local density functional theory was proposed to improve the predictive power of the Hartree−Fock model for molecular bonding, and the results of tests on atomization energies, ionization potentials, and proton affinities were reported.
15.7K
Optimization of equilibrium geometries and transition structures
TL;DR: In this paper, a modified conjugate gradient algorithm for geometry optimization is presented for use with ab initio MO methods, where the second derivative matrix rather than its inverse is updated employing the gradients.
3.7K
Gaussian-2 theory for molecular energies of first- and second-row compounds
TL;DR: The Gaussian-2 theoretical procedure (G2 theory) as discussed by the authors was proposed to calculate molecular energies (atomization energies, ionization potentials, and electron affinities) of compounds containing first and second-row atoms.
3.4K