Effects of external electric fields on the stability and thermal decomposition pathways of triazole-triazine-based energetic materials: a case study of TTX and its derivatives.

Context: High-nitrogen polycyclic compounds have become a research hotspot in the design of new energetic molecules due to their dense nitrogen content, high positive enthalpy of formation, and good structural stability. In particular, the fused structures of triazole and triazine heterocycles can not only enhance energy output but also possess excellent thermal stability. This study focuses on three triazolotriazine energetic compounds: 3,7-dinitro-[1,2,4]triazolo[5,1-c][1,2,4]triazin-4-amine (TTX), 7-nitro-3-(1H-tetrazol-5-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazin-4-amine (compound 1), and 3,3'-dinitro-[7,7'-bi[1,2,4]triazolo[5,1-c][1,2,4]triazine]-4,4'-diamine (compound 2).

Electrostatic field modulation of high-nitrogen heterocycles: a computational study on energy and stability.

Context: In this study, the effect of external electric field (EEF) on three kinds of high nitrogen heterocyclic compounds with different ring structures (PA-1 ~ 3, oxadiazole, triazole, and tetrazole) was investigated by quantum chemical calculation. By using B3LYP/6-311G + (d, p) theory and Laplace bond order (LBO) analysis, the trigger bond was determined, and further EEF was applied along the X/Y/Z axis (0-0.02 a.

Quantum chemical calculations based on 4,5-di(1,2,4-oxadiazol-3-yl)-2H-1,2,3-triazole and 3,3' -(2H-1,2,3-triazole-4,5-diyl)-bis(1,2,4-oxadiazol-5(4H)-one) derivatives: a DFT study.

Context: 1,2,3-Triazole has excellent thermal stability, and both 1,2,3-triazole and 1,2,4-oxazolium are good in structural modifiability. This study employed density functional theory (DFT) to design 24 target compounds (designated PA-1 to PA-24) based on the characteristics of these two heterocyclic systems. Using 4,5-diallyl-2H-1,2,3-triazole-3,3'-(2H-1,2,3-triazole-4,5-diyl)-bis(1,2,4-oxadiazol-5(4H)-one) as the parent compound (labeled A1), we introduced different energetic substituents at the C3 position of the oxadiazole ring and the N2 position of the triazole ring.

The influence of external electric field on the structure of pentazole ionic salt.

Context: Pentazole ion salt is a cutting-edge new type of all-nitrogen ion high-energy material. When subjected to an external electric field (EEF), the structure and various properties of pentazole ion salts are altered. This article studied six types of pentazole ion salts (PA-1 ~ PA-6) under an external electric field (intensity 0 ~ 0.

Structure and properties of pentazole ionic salts.

Context: Based on the periodic density functional theory, we systematically studied 13 kinds of anhydrous pentazole non-metallic ionic salts synthesized by other scientists (PA-1 ~ PA-13)[Chem-An Asian J, 13(8):924-928 6, J Am Chem Soc 140(48):16488-16494 7, J Mater Chem A 7(20):12468-12479 8, Chem-An Asian J 14(16):2877-2882 9]. The results show the following: first, the heat of formation of PA-1 ~ PA-13 exceeds that of TNT and RDX. The heat of formation of PA-9 reaches 1357.

First-principles study on energetic cocrystals of CL-20/4,5-MDNI with two different stoichiometric ratios under high pressure.

Context: This research determined the crystal structure, molecular structure, electronic structure, optical properties, mechanical properties, and Hirshfeld analysis of the CL-20/4,5-MDNI cocrystal at two distinct stoichiometric ratios under hydrostatic pressures varying from 0 to 100 GPa. The findings revealed that the CL-20/4,5-MDNI cocrystal with a 1:1 ratio experienced two structural transitions at pressures of 80 GPa and 90 GPa. Notably, new covalent bonds, C10-O13 and C9-O14, were established, whereas the C10-H10C bond was disrupted.

[Analysis of the treatment of a premature infant with critical coronavirus disease caused by the Omicron variant of SARS-CoV-2].

The patient is a female infant who was born at a gestational age of 30 weeks in the breech position and was delivered by assisted vaginal delivery. She was admitted to the neonatal department of Tianjin First Central Hospital for 44 days, during which she had stable respiration, oxygen saturation, and regular weight gain. The patient was discharged home by her family.

[Change in serum IgG antibody during the recovery stage of Omicron variant infection in children: an analysis of 110 cases].

Objectives: To investigate the serum level of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific RBD IgG antibody (SARS-CoV-2 IgG antibody for short) in children with SARS-CoV-2 Omicron variant infection during the recovery stage, as well as the protective effect of SARS-CoV-2 vaccination against Omicron infection.

Methods: A retrospective analysis was performed on 110 children who were diagnosed with coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 Omicron variant infection in Tianjin of China from January 8 to February 7, 2022. According to the status of vaccination before diagnosis, they were divided into a booster vaccination (3 doses) group with 2 children, a complete vaccination (2 doses) group with 90 children, an incomplete vaccination (1 dose) group with 5 children, and a non-vaccination group with 13 children.