Over the last several decades, saturated polycyclic cage compounds have remained a point of interest for organic chemists because of their unique characteristics and reactivity. For the first time, a detailed analysis of the synthesis, properties and transformations of 1,3-bishomocubanes, which fall under the rare category of chiral cage compounds, is provided in this article. This review which also includes the authors' work in this area over the last decade is expected to serve as a valuable resource for chemists interested in the fascinating chemistry and properties of polycyclic cage compounds.
View Article and Find Full Text PDFThe present work reports synthesis, characterization and theoretical insights on novel hydroxymethyl-bishomocubanone derivatives. Twelve new bishomocubanes (BHCs) were synthesized and fully characterized by various spectroscopic techniques and single crystal X-ray analysis. The densities of the title compounds were in the range of 1.
View Article and Find Full Text PDFNovel 1,4-disubstituted cubane derivatives have been designed and selected ones have been successfully synthesized and characterized by various analytical and spectroscopic techniques, including single-crystal X-ray analysis. A detailed computational study at B3LYP/6-311++G(d,p) level of theory revealed that all newly designed 1,4-disubstituted cubane derivatives possess higher densities, higher density-specific impulse and superior ballistic properties when compared to conventional fuels, for example, RP-1. These compounds also exhibit acceptable kinetic and thermodynamic stabilities which were evaluated in terms of their HOMO-LUMO energy gap and bond dissociation energies, respectively, and are superior to TEX and many other compounds containing explosophoric groups.
View Article and Find Full Text PDFThe accurate measurement of temperature in sooty flames remains a challenging task. In this study, the procedure for calibration and use of a consumer-grade digital single-lens reflex (DSLR) camera for the measurement of temperature in sooty flames using color-ratio pyrometry (CRP) is elucidated. Owing to the necessity of acquiring RAW images for CRP, investigations conducted thus far have been limited to stable flames.
View Article and Find Full Text PDFThis work provides new insights for the liquid-phase decomposition of bis(triaminoguanidinium) azotetrazolate (TAGzT). The liquid-phase decomposition process was investigated using a combined experimental and computational approach. Sub-milligram samples of TAGzT were heated at rates of about 2000 K s-1 to a set temperature (230 to 260 °C) where liquid-phase decomposition occurred under isothermal conditions.
View Article and Find Full Text PDFPyrolysis is an attractive thermochemical conversion technology that may be utilised as a safe disposal option for acid tar waste. The kinetics of acid tar pyrolysis were investigated using thermogravimetry coupled with mass spectrometry under a nitrogen atmosphere at different heating rates of 10, 15 and 20 K min The thermogravimetric analysis shows three major reaction peaks centred around 178 °C, 258 °C, and 336 °C corresponding to the successive degradation of water soluble lower molecular mass sulphonic acids, sulphonated high molecular mass hydrocarbons, and high molecular mass hydrocarbons. The kinetic parameters were evaluated using the iso-conversional Kissinger-Akahira-Sunose method.
View Article and Find Full Text PDFSeveral high-energy-density strained polycyclic compounds nitromethyl-l,3-bishomocubane (NMBHC), nitromethylene-1,3-bishomocubane (NMyBHC), and bis(nitromethyl)-1,3-bishomocubane (DNTMBHC), which were synthesized for the first time from bishomocubanone, hold potential for application as standalone fuels in liquid bipropellant systems or as additives in liquid and solid propellant formulations. DFT analysis at the B3LYP/6-31G(d) level of theory was employed to optimize the geometries of the compounds and to determine their densities, heats of formation, and various thermodynamic properties. The density specific impulse, determined by using equilibrium thermodynamics, demonstrated an improvement of 75 s for NMBHC and NMyBHC over standard hydrocarbons.
View Article and Find Full Text PDFThe determination of the condensed-phase preignition chemistry of hypergolic bipropellant pairs has been considerably challenging due to toxicity and reactivity of the used materials. In this work, we describe a new experimental technique for characterizing preignition behavior of hypergolic materials. Small quantities of the bipropellant pair are brought in contact under isothermal conditions, and spectral transmission measurements on the evolved products are performed using Fourier transform infrared spectroscopy.
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