TY - JOUR

T1 - Metal-Free Reversible Double Cyclization of Cyanuric Diazide to an Asymmetric Bitetrazolate via Cleavage of the Six-Membered Aromatic Ring

AU - Vaddypally, Shivaiah

AU - Byrne, Alex N

AU - Goldsmith, C Franklin

AU - Zdilla, Michael J

AU - Kiselev, Vitaly G

N1 - The authors acknowledge ONR for support under Awards N00014-22-1-2060 (to M.J.Z.) and N00014-21-2291 (to C.F.G.). V.G.K. acknowledges the Supercomputer Center of Novosibirsk State University and the Russian Science Foundation for financial support of the computational part of this work (project 19-73-20217-P). Crystallography was supported by a grant from the National Science Foundation under MRI Award CHE-2215854.

PY - 2024/2/5

Y1 - 2024/2/5

N2 - Crystallization of the reaction mixture of 2-amino-4,6-diazido-1,3,5-triazine and excess tert-butylamine results in the isolation of tert-butylammonium N,N-[1'H-(1,5'-bitetrazol)-5-yl]cyanamidate, suggesting a complex decyclization/cyclization rearrangement involving breakage of the six-membered aromatic ring and the formation of two new five-membered azole rings mediated by deprotonation of the precursor by the amine. The addition of tert-butylamine to 2-amino-4,6-diazido-1,3,5-triazine gives spectroscopic indication of thermodynamically unfavorable reactivity in low-dielectric solvents, and high-level quantum chemical computations also suggest its formation to be unfavorable. A computed interconversion pathway describes the likely reaction mechanism and supports the general thermodynamic unfavorability of the reaction and the requirement for a high-dielectric environment to template formation of the ionic product and its trapping by crystallization.

AB - Crystallization of the reaction mixture of 2-amino-4,6-diazido-1,3,5-triazine and excess tert-butylamine results in the isolation of tert-butylammonium N,N-[1'H-(1,5'-bitetrazol)-5-yl]cyanamidate, suggesting a complex decyclization/cyclization rearrangement involving breakage of the six-membered aromatic ring and the formation of two new five-membered azole rings mediated by deprotonation of the precursor by the amine. The addition of tert-butylamine to 2-amino-4,6-diazido-1,3,5-triazine gives spectroscopic indication of thermodynamically unfavorable reactivity in low-dielectric solvents, and high-level quantum chemical computations also suggest its formation to be unfavorable. A computed interconversion pathway describes the likely reaction mechanism and supports the general thermodynamic unfavorability of the reaction and the requirement for a high-dielectric environment to template formation of the ionic product and its trapping by crystallization.

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85184344373&origin=inward&txGid=afdc054dbf14227b0bcd32c64e1d2300

U2 - 10.1021/acs.inorgchem.3c04338

DO - 10.1021/acs.inorgchem.3c04338

M3 - Article

C2 - 38262914

VL - 63

SP - 2322

EP - 2326

JO - Inorganic Chemistry

JF - Inorganic Chemistry

SN - 0020-1669

IS - 5

ER -