Heats of Combustion and Formation of Trimethylborane, Triethylborane, and Tri--butylborane.

The heats of combustion at 25 °C of trimethylborane (liquid), triethylborane (liquid), and tri--butylborane (liquid), to form crystalline boric acid, liquid water, and gaseous carbon dioxide have been determined to be -2989.4 ±22.4 kj/mole (-714.48 ±5.36 kcal/mole), -4975.6 ±15.1 kj/mole (-1189.2 ±3.6 kcal/mole), and -8901.0 ±10.2 kj/mole (-2127.4 ±2.4 kcal/mole), respectively. These data, combined with the heats of formation of boric acid, carbon dioxide, and water give -34.79 ±5.40, -47.2 ±3.7, and -83.2 ±2.5 kcal/mole at 25 °C for the standard heats of formation of trimethylborane, triethylborane, and tri--butylborane, respectively. The data of other investigators are discussed briefly.