Explain the following observations. 1. Aziridines, compounds that contain nitrogen in a three-membered ring, undergo pyramidal inversion much more slowly than do other alkylamines. 2. The rate constant for formation of tetraethylammonium iodide form triethylamine and ethyl iodide is more than 800 times greater (at 100 degrees celsius) when the solvent is acetone than when it is hexane. The respective dielectric constrants are 21 for acetone and 1.9 for hexane.