Unprecedented Cyclic Isomer of Triazenes: A Computational Identification

Abstract

Isomerism is very important in chemistry. Over the past 65 years, the energy-rich N 3 R 3 family has received considerable attention both experimentally and computationally. Up to now, four isomeric types of N 3 R 3 have been identified, i.e., triazenes I, triimides II, iso-triazenes III, and cyclo-triazanes IV. In this work, via the composite CBS-QB3 study on the isomers and transition states of N 3 H 3 -the simplest N 3 R 3 system, we unexpectedly found a new structural type V, which contains a N 3 threemembered ring with one nitrogen-nitrogen dative bond in the ring (i.e., cyclic ammonia-nitrene interaction). Of all the N 3 H 3 isomers, V lies the highest in energy (78.7 kcal/mol above the global triazene) and possesses a relatively low conversion barrier 8.9 kcal/mol. Yet quite promisingly, suitably choosing substituents can tune the rate-determining barrier of V to reach around 20 kcal/mol. Thus, synthesis of the newly found triazene isomer V is highly probable.

Construction of New Azo‐group Containing Polycyclic Imidazole Derivatives: Computational Mechanistic, Structural, and Fluorescence Studies

“…One‐pot cyclocondensation reaction was carried out before with valuable metal catalysts . Computational tools were applied extensively to structural analysis and mechanistic studies previously . We turn to computation investigating low‐cost and superior IL catalyst with satisfactory TOF (turnover frequency) value (Table ) and a mechanism of the reaction (Scheme ).…”