@article {2231, title = {State-of-the-art in atmospheric pressure photoionization for LC/MS}, journal = {Analytica Chimica Acta}, volume = {627}, number = {1}, year = {2008}, note = {ISI Document Delivery No.: 358IYTimes Cited: 23Cited Reference Count: 147Robb, Damon B. Blades, Michael W.Sp. Iss. SI}, month = {Oct}, pages = {34-49}, type = {Review}, abstract = {This review presents our perspective on the state-of-the-art of atmospheric pressure photoionization (APPI) for LC/MS. Its focus is on APPI{\textquoteright}s capabilities and how to utilize them fully. The introduction includes a brief recounting of the history of APPI{\textquoteright}s development, as well as a summary of its operating principles and current position in the field. The primary ionization mechanisms in APPI are then addressed, including direct analyte photoionization (PI), dopant/solvent PI, and thermospray. Next a summary of the ion-molecule reaction pathways available for analyte ionization is presented, along with the conditions required for activating them. APPI{\textquoteright}s performance characteristics are then examined. in effect, this review is an interim report on progress made since Rafaelli and Saba concluded that "The ability... to direct the preferential ion formation towards one particular type...can be extremely useful for qualitative and quantitative determinations. For this purpose, a better insight in the processes involved in the ionization step is strongly needed" [A. Raffaelli, A. Saba, Mass Spectrom. Rev. 22 (2003) 318]. In the conclusion, we focus on areas of APPI technology identified as being either unoptimized or largely unexplored, and having the potential to be improved upon-the crux being that with further research and development improvements in the performance, capabilities, and ease-of-use of APPI may reasonably be anticipated. (C) 2008 Elsevier B.V. All rights reserved.}, keywords = {ACTIVATED CHEMICAL-IONIZATION, AROMATIC-HYDROCARBONS, atmospheric pressure, BROMINATED FLAME RETARDANTS, CARBON, ELECTROSPRAY-IONIZATION, HUMAN PLASMA, LC-MS/MS, liquid chromatography/mass, LIQUID-CHROMATOGRAPHY, PHOTOIONIZATION, POLYCYCLIC, POROUS GRAPHITIC, PROTON-TRANSFER, review, SPECTROMETRY, TANDEM-MASS-SPECTROMETRY}, isbn = {0003-2670}, url = {://000259911600004}, author = {Robb, D. B. and Blades, M. W.} } @article {377, title = {Cyclohexadienyl niobium complexes and arene hydrogenation catalysis}, journal = {Organometallics}, volume = {21}, number = {23}, year = {2002}, note = {ISI Document Delivery No.: 612WDTimes Cited: 6Cited Reference Count: 45}, month = {Nov}, pages = {5047-5054}, type = {Article}, abstract = {Hydrogenolysis of (R)[P2N2]NbCH2SiMe3 (where (R)[P2N2] = RP(CH2SiMe2NSiMe2CH2)(2)PR; R = cyclohexyl, Cy, or phenyl, Ph) in benzene or toluene causes hydride addition to the aromatic solvent resulting in the formation of the pi-bonded complexes (R)[P2N2]Nb(eta(5)-C6H7) (R = Cy, 1; R = Ph, 2) and (R)[P2N2]Nb(eta(5)-C7H9) (R = Cy, 3; R = Ph, 4) in benzene and toluene, respectively. Performing the hydrogenation at a higher pressure of 29 atm at room temperature causes the catalytic hydrogenation of benzene to cyclohexane as determined by NMR spectroscopy and GC-MS analysis. The hydrogenation of toluene to methylcyclohexane can also be performed, but the turnover frequency is considerably lower. Examination of the solid residues from the high-pressure hydrogenations indicates the formation of the pi-bonded complexes 1 and 2. The additionof 29 atm of H-2 to these cyclohexadienyl derivatives in benzene or toluene, however, shows no hydrogenation products, indicating these species are not catalytically active.}, keywords = {AROMATIC-HYDROCARBONS, BOND, CHEMISTRY, CRYSTAL-STRUCTURE, HOMOGENEOUS HYDROGENATION, LIGANDS, TANTALUM DIHYDRIDE}, isbn = {0276-7333}, url = {://000179097700024}, author = {Fryzuk,Michael D. and Kozak, C. M. and Bowdridge, M. R. and Patrick, B. O.} }