Carbo rane reactions with

Similar to fluorination, iodination of o-carborane (1) has been carried out primarily through electrophilic iodination or by nucleophilic deboronation followed by reconstruction of the carbo-rane cage with BI3 (Scheme 6.2) (Yamazaki et al., 2005). Depending on the stoichiometric quantity of molecular iodine (Ij), the electron-rich borons 9 and 12 of 1 can be iodinated easily in the presence of AICI3 to give 9-iodo-o-carborane (17) and/or 9,12-diiodo-o-carborane (18) (Li et al., 1991 Yamazaki et al., 2005), whereas the reaction of compound 14 with boron triiodide (BI3) afforded 3-iodo-o-carborane (19, 74% yield) (Yamazaki et al., 2005). 

When one considers the potential high-energy release on rupture of a carborane unit, together with the thermodynamic stability of combustion products, it is hardly surprising that there is a body of literature that reports on the use of carbo-ranes within propellant compositions. Their use in energetic applications is to be expected when the enthalpy of formation (AH/) data for the products of combustion for boron are compared to those of carbon. Thermodynamic data for the enthalpy of formation of o-carborane and of typical boron and carbon combustion products is shown in Table 4. Measurements of the standard enthalpy of combustion32 for crystalline samples of ortho-carborane show that complete combustion is a highly exothermic reaction, AH = — 8994 KJmol. ... 

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