Zwitterion-dianion complexes and anion-anion clusters with negative dissociation energies.
Clusters of oxalate and malonate dianions with glycine in its zwitterionic form were found by ab initio and density functional theory calculations. Proton transfer is impeded by an electrostatic barrier, but the resulting anion-anion pairs form complexes despite having negative dissociation energies. A variety of X-/Y- species with exothermic dissociation energies ranging from 10 to 141 kcal mol-1, but large enough barriers to be experimentally produced, are reported. These dianions may represent an unrecognized control element in nature and provide a unique opportunity to probe electrostatic effects and a wealth of novel clusters.
Kass
Steven R
SR
Contribution from the Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA. kass@chem.umn.edu
D000838:Anions / Q000737:chemistry; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D009930:Organic Chemicals / Q000737:chemistry*; D013816:Thermodynamics
D000838:Anions; D009930:Organic Chemicals