Catalytic Effects of Ruthenocene Bimetallic Compounds Derived from Fused Aromatic Ring Ligands on the Main Oxidizing Agent for Solid Rocket Motor

We report the catalytic effect of three ruthenocene bimetallic compounds derived from fused aromatic rings of general formula [{Cp*Ru}2L], with Cp*: pentamethylcyclopentadiene and L = pentalene (1), 2,6-diethyl-4,8-dimethyl-s-indacene (2), and 2,7-diethyl-as-indacene (3), on the thermal decomposition of ammonium perchlorate (AP). The new compound 3 was characterized by a combination of multinuclear magnetic resonance (NMR) spectroscopy and elemental analysis. The differential scanning calorimetry (DSC) analysis of compound 3 shows a decrease in the decomposition temperature of AP to 347 ºC, increases the energy release to 2048 J g-1 and, consequently, leads to the lowest activation energy (42.9 kJ mol−1). These results are comparable to the typically used metallocene (catocene: 347 ºC and 2472 J g-1), suggesting a suitable and competitive alternative to be used as a modifier for composite solid propellants.

‘Oxygen-Consuming Complexes’–Catalytic Effects of Iron–Salen Complexes with Dioxygen

[(salen)FeIII]+MeCN complex is a useful catalyst for cyclohexene oxidation with dioxygen. As the main products, ketone and alcohol are formed. In acetonitrile, [(salen)FeII]MeCN is rapidly oxidized by dioxygen, forming iron(III) species. Voltammetric electroreduction of the [(salen)FeIII]+MeCN complex in the presence of dioxygen causes the increase in current observed, which indicates the existence of a catalytic effect. Further transformations of the oxygen-activated iron(III) salen complex generate an effective catalyst. Based on the catalytic and electrochemical results, as well as DFT calculations, possible forms of active species in c-C6H10 oxidation have been proposed.