Abstract: A series of substituted diphenylcyclopropenium tetrafluoroborates, Ph&X+ BF4-(I), has been prepared, and their~ KR+ values have been measured by potentiometric titration. The trend observed, R2N>> cC, Hs> OEt> n-CaH7= SMe> Ph> H, indicates conjugative effects still to be predominant in stabilizing these cations, though less so than with most other cations. No evidence of abnormal phenyl effects is found. ...
