Interaction of the unusual bonds in cyclopropane with an extra electron in the dense fluid

An unexpectedly strong interaction between electrons and closely packed cyclopropane molecules has been discovered through measurement of electron mobilities in the liquid and gas phases. In the low density vapors the mobilities fell in the expected order cyclopropane > propane > propene; at STP they were 9000, 6000, and 2040 cm2/V s, respectively. In the liquids the order was propane > propene > cyclopropane; at 273 K the mobilities were 1.4, 0.12, and 0.017 cm2/V s, respectively. The abnormally low mobility in liquid cyclopropane is attributed to the formation of transient dimeric anions. The reaction is only significant at densities greater than about 0.4 times the critical density.