Quantum-chemical calculations of the enthalpy of formation for 5/6/5 tricyclic tetrazine derivatives annelated with nitrotriazoles

Abstract

The paper presents the study of the calculated physicochemical properties of new high-energy 5/6/5 tricyclic structures, which are 1,2,3,4- or 1,2,4,5-tetrazines, fused with a pair of 1H-1,2,4-, 4H-1,2,4- or 1H-1,2,3-triazoles. Values of the enthalpy of formation in the gaseous phase have been determined by high-performance quantum-chemical calculations (within Gaussian 09 program package) using various methods for solving the stationary Schrödinger equation, including G4, G4MP2, ωB97XD/aug-cc-pVTZ, CBS-APNO, CBS-QB3, CBS-4M, B3LYP/6-311+G(2d,p), M062X/6-311+G(2d,p). The results of calculations obtained by the methods of atomization and isogyric reactions have been analysed. Various calculation methods have been compared in terms of accuracy and time consumption.