Synthesis and Characterization of a Dinuclear Nitrogen‐Rich Ferrocenyl Ligand and Its Ionic Coordination Compounds and Their Catalytic Effects During Combustion

Abstract

Alkylferrocene-based burning-rate catalysts (BRCs) exhibit distinct migration tendency and high volatility and thus result in inferior performance of composite solid propellants during their combustion processes. To deal with these drawbacks, a novel dinuclear nitrogen-rich ferrocene derivative, 4-amino-3,5-bis(4-ferrocenyl-1,2,3triazolyl-1-methyl)-1,2,4-triazole (BFcTAZ) and its twenty seven ionic coordination compounds, [M 2 (BFcTAZ) 2 (H 2 O) 4 ] m X n ·xH 2 O (M = Cr 3+ , Mn 2+ , Fe 3+ , Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ , Cd 2+ and Pb 2 ; X = polycyano anions), were synthesized and characterized by FT-IR, UV/Vis, and elementary analysis. Crystal structure of BFcTAZ was further confirmed by single-crystal X-ray diffraction and a general molecular 92 structure of the new complexes was proposed. Their high thermal stability was verified by TG technique. Cyclic voltammetry studies suggested that the new compounds are diverse redox systems. Their effects on the thermal degradation of some common oxidizers were measured by DSC technique. The results indicated that most of the new complexes exert great effects on the thermal decomposition of AP, RDX, and 1,1-diamino-2,2-dinitroethylene (FOX-7) and some of them are more active than catocene. The Cu 2+ complexes are among the excellent ones. However, only six compounds have appreciable catalytic activity in the thermal degradation of HMX. Scheme 1. Molecular structure of the synthesized dinuclear nitrogenrich ferrocenyl compound BFcTAZ.

Evaluation of Mono and Bimetallic Ferrocene-Based 1,2,3-Triazolyl Compounds as Burning Rate Catalysts for Solid Rocket Motor

“…The thermal stability of ferrocene-based 1,2,3-triazolyl compounds was assessed using the TG technique. As depicted in Figure S18, their weight loss began over 118 °C, except for compound 1-IL (91.9 °C), obtaining a considerable loss of mass at the temperatures of 292, 318, 271, and 275 °C for compounds 1 , 2 , 1-IL , and 2-IL , respectively, highlighting their considerable resistance to high temperatures, suggesting that they are of high thermal stability, as was mentioned by Zhang and Zhao. − …”

“…Researchers have tried overcoming the high-migration and volatility problems with ferrocene-based burn rate (BR) catalysts in recent decades. These efforts involved diverse approaches such as developing ferrocenyl group-grafted polymers , and dendrimers, , introducing concepts of ionic coordination compounds and energetic ionic ferrocene, , besides increasing the molecular weights of ferrocene-based BR catalysts. − In the last ten years, Zhang and co-workers have utilized the concept of energetic ionic compounds to develop energetic ionic ferrocenyl compounds to tackle high-migration problems. Recently, Zhang’s group has published the synthesis of various nitrogen-rich N-heterocyclic ferrocene-functionalized pyrazole and 1,2,3-triazolyl compounds and their effects on the thermal stability and combustion properties of composite propellants, showing exceptional antimigration ability and electrochemical properties, confirming that high nitrogen content in a ferrocenyl derivative improves its catalytic combustion performance in the thermal degradation of AP. , …”

“…Researchers have tried overcoming the high-migration and volatility problems with ferrocene-based burn rate (BR) catalysts in recent decades. These efforts involved diverse approaches such as developing ferrocenyl group-grafted polymers 29 , 30 and dendrimers, 22 , 31 introducing concepts of ionic coordination compounds 32 and energetic ionic ferrocene, 33 , 34 besides increasing the molecular weights of ferrocene-based BR catalysts. 35 − 37 In the last ten years, Zhang and co-workers have utilized the concept of energetic ionic compounds to develop energetic ionic ferrocenyl compounds to tackle high-migration problems.…”

Insights From Differential Scanning Calorimetry and Cyclic Voltammetry Analyses: Studies of the Synergistic Effect of Two Different Metallocenes on the Main Oxidizing Agent for Solid Rocket Motor

“…Nowadays, different types of BR catalysts have been studied, where they have mainly been related to iron derivatives such as nanoparticles [2][3], coordination complexes, [3] and ferrocene derivatives [5][6][7]. Regarding ferrocene derivatives have excellent properties and compatibility with the commonly used binder agent, HTPB/AP (hydroxyl-terminated polybutadiene); these specific properties generate a stable composite solid propellant [8][9].…”