PROBING THE POTENTIAL BARRIERS AND INTRAMOLECULAR ELECTROSTATIC INTERACTIONS IN FREE DOUBLY-CHARGED ANIONS

Multiply charged anions, though ubiquitous in nature, have been diffic ult to produce and study in the gas phase. Photoelectron spectroscopy has been combined with an electrospray ion source to probe the repulsi ve Coulomb barriers, excess electron binding, and intramolecular elect ron-electron interactions in a series of dicarboxylate dianions, O2C(C H2)(n)CO2- (n = 3-10). These experiments provide quantitative informat ion about the repulsive Coulomb barriers and how the excess electron b inding energy and the barrier height depend on the intramolecular Coul omb repulsion. [S0031-9007(98)07243-3].