The dipropylcyclopropenyl cation and the tripropylcyclopropenyl cation have been synthesized. Comparison of their PK's shows that the alkyl groups have a considerable effect on the stability of the cyclopropenyl cation, and this is confirmed by a comparison of the pK's of diphenylcyclopropenyl cation and propyldiphenylcyclopropenyl cation. The stabiliration by propyl groups is even larger than that by phenyls, and this suggests that ...
