Water dimer dipole anion

From a historical perspective, the first unambiguous observation of dipole states came from the group of Kit Bowen (Johns Hopkins) in 1990, who studied the important water dimer dipole anion. The Bowen group has also studied ground state dipole-bound anions produced by electron attachment under high-pressure nozzle-jet expansion condition. They have also used photodetachment photoelectron spectroscopy to determine electron affinities for a number of the molecules shown in Figure 4. 

H.-Y. Chen and W.-S. Sheu,/. Chem. Phys., 110, 9032-9038 (1999). Dipole-Bound Anion of Water Dimer Theoretical ab-Initio Study. 

The solvated C02 anion radical has been observed both in the gas phase and in condensed matter (Holroyd et al. 1997) and has been well characterized by ESR spectroscopy (Knight et al. 1996). Being solvated, C02 anion radicals form complexes that yield quasi-free electrons upon photoexcitation. Gas-phase studies (Saeki and others 1999) and ab initio calculations (Tsukuda et al. 1999) indicate that static ion-dipole interactions stabilize the [(C02)n m(R0H)m] type of small clusters. In supercritical carbon dioxide, monomers and dimers of water, acetonitrile, and alcohols also form metastable complexes (Shkrob Sauer 2001a,b). Such complexation should be taken into account in studies of electron-transfer kinetics in reactions with the participation of C02. ... 

---