<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Tonner, R.</style></author><author><style face="normal" font="default" size="100%">Schwerdtfeger, P.</style></author><author><style face="normal" font="default" size="100%">May, A. L.</style></author><author><style face="normal" font="default" size="100%">Steill, J. D.</style></author><author><style face="normal" font="default" size="100%">Berden, G.</style></author><author><style face="normal" font="default" size="100%">Oomens, J.</style></author><author><style face="normal" font="default" size="100%">Campagna, S. R.</style></author><author><style face="normal" font="default" size="100%">Compton, R. N.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Stability of Gas-Phase Tartaric Acid Anions Investigated by Quantum Chemistry, Mass Spectrometry, and Infrared Spectroscopy</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Physical Chemistry A</style></secondary-title><alt-title><style face="normal" font="default" size="100%">J. Phys. Chem. A</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">AB-INITIO</style></keyword><keyword><style  face="normal" font="default" size="100%">AUXILIARY</style></keyword><keyword><style  face="normal" font="default" size="100%">BASIS-SETS</style></keyword><keyword><style  face="normal" font="default" size="100%">DICARBOXYLATE DIANIONS</style></keyword><keyword><style  face="normal" font="default" size="100%">ELECTRON-AFFINITIES</style></keyword><keyword><style  face="normal" font="default" size="100%">HARMONIC APPROXIMATION</style></keyword><keyword><style  face="normal" font="default" size="100%">IONIZATION-POTENTIALS</style></keyword><keyword><style  face="normal" font="default" size="100%">IONS</style></keyword><keyword><style  face="normal" font="default" size="100%">MOLECULES</style></keyword><keyword><style  face="normal" font="default" size="100%">MULTIPLY-CHARGED ANIONS</style></keyword><keyword><style  face="normal" font="default" size="100%">REPULSIVE COULOMB BARRIER</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year><pub-dates><date><style  face="normal" font="default" size="100%">May</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://WOS:000304073200013 </style></url></web-urls></urls><number><style face="normal" font="default" size="100%">19</style></number><volume><style face="normal" font="default" size="100%">116</style></volume><pages><style face="normal" font="default" size="100%">4789-4800</style></pages><isbn><style face="normal" font="default" size="100%">1089-5639</style></isbn><language><style face="normal" font="default" size="100%">English</style></language><abstract><style face="normal" font="default" size="100%">In an effort to understand the chemical factors that stabilize dianions, experimental and theoretical studies on the stability of the tartrate dianion were performed. Quantum chemical calculations at the coupled cluster level reveal only a metastable state with a possible decomposition pathway (O2C-CH(OH)-CH(OH)-CO2)(2-) -&gt; (O2C-CH(OH)-CH(OH))(center dot-) + CO2 + e(-) explaining the observed gas-phase instability of this dianion. Further theoretical data were collected for the bare dianion, this molecule complexed to water, sodium, and a proton, in both the meso and L forms as well as for the uncomplexed radical anion and neutral diradical. The calculations suggest that the L-tartrate dianion is more thermodynamically stable than the dianion of the meso stereoisomer and that either dianion can be further stabilized by association with a separate species that can help to balance the charge of the molecular complex. Mass spectrometry was then used to measure the energy needed to initiate collisionally induced dissociation of the racemic tartrate dianion and for the proton and sodium adducts of both the racemic and meso form of this molecule. Infrared action spectra of the dianion stereoisomers complexed with sodium were also acquired to determine the influence of the metal ion on the vibrations of the dianions and validate the computationally predicted structures. These experimental data support the theoretical conclusions and highlight the instability of the bare tartrate dianion. From the experimental work, it could also be concluded that the pathway leading to dissociation is under kinetic control because the sodium adduct of the racemic stereoisomer dissociated at lower collisional energy, although it was calculated to be more stable, and that decomposition proceeded via C-C bond dissociation as computationally predicted. Taken together, these data provide insight into the gas-phase stability of the tartrate dianion and highlight the role of adducts in stabilizing this species.</style></abstract><work-type><style face="normal" font="default" size="100%">Article</style></work-type><accession-num><style face="normal" font="default" size="100%">WOS:000304073200013</style></accession-num><notes><style face="normal" font="default" size="100%">ISI Document Delivery No.: 942TSTimes Cited: 0Cited Reference Count: 72</style></notes><custom1><style face="normal" font="default" size="100%">GUTHz</style></custom1><custom2><style face="normal" font="default" size="100%">Mocular Dynamics</style></custom2><auth-address><style face="normal" font="default" size="100%">[May, Amanda L.; Steill, Jeffrey D.; Campagna, Shawn R.; Compton, Robert N.] Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. [Tonner, Ralf; Schwerdtfeger, Peter] Univ Marburg, Fachbereich Chem, D-35032 Marburg, Germany. [Schwerdtfeger, Peter] Massey Univ Albany, NZIAS, Auckland, New Zealand. [Steill, Jeffrey D.; Berden, Giel; Oomens, Jos] FOM Inst Plasma Phys Rijnhuizen, NL-3439 MN Nieuwegein, Netherlands. [Oomens, Jos] Univ Amsterdam, Vant Hoff Inst Mol Sci, NL-1098 XH Amsterdam, Netherlands. [Compton, Robert N.] Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA.Campagna, SR (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USAcampagna@ion.chem.utk.edu; compton@ion.chem.utk.edu</style></auth-address></record></records></xml>