B. Dogan

Geminale substituenteneffekte: Teil I. Thermochemie von 1-nitro-, 2-nitro-, 2,2-dinitro-und 2-cyano-2-nitroadamantan

Abstract The heats of combustion of 1-nitroadamantane ( 1 ), 2-nitroadamantane ( 2 ), 2,2-di-nitroadamantane ( 3 ) and 2-cyano-2-nitroadamantane ( 4 ) were measured by combustion calorimetry, and the heats of sublimation were derived from the temperature dependence of the vapour pressure measured in a flow system. The results for Δ H XXX c (c) and Δ H Sub (in kJ mol −1 , standard deviation in parentheses) are: 1 , −5824.1 (±2.2) and 63.6 (±1.0); 2 , −5841.0 (±2.2) and 58.0 (±2.3); 3 , −5685.2 (±1.0) and 96.4 (±1.4); 4 , −6238.4 (±1.5) and 70.0 (±1.9). A comparison of the resulting heats of formation Δ H XXX f (g) (in kJ mol −1 , standard deviation in parentheses) for 1 = −191.1 (± 2.4), 2 = −179.8 (±3.2), 3 = −154.3 (±1.7) and 4 = −21.0 (±2.5) reveals a destabilizing interaction of the geminal substituents in 3 and 4 amounting to 59 kJ mol −1 (nitro/nitro) and 33 kJ mol −1 (nitro/cyano) respectively.