18155-21-0Relevant articles and documents
Gas-phase ion chemistry of HP2-, FP2-, and HP2+
O'Hair, Richard A. J.,Krempp, Michèle,Damrauer, Robert,DePuy, Charles H.
, p. 2092 - 2096 (2008/10/08)
The gas-phase ion-molecule chemistry of the mass-selected ions HP2-, FP2-, and HP2+ has been studied in a tandem flowing afterglow selected-ion flow tube (FA-SIFT). Both HP2- and HP2+ are formed by direct electron impact on phosphine, followed by subsequent ion-phosphine reactions in the first flow tube. The related ion, FP2-, is formed via an ion-molecule reaction between HP2- and hexafluorobenzene. We have observed a number of reactions of HP2-, including hydride transfer and proton abstraction, as well as fluoride transfer and proton abstraction for FP2-. Using bracketing techniques, the gas-phase proton affinity of P2 has been determined as 162 ± 3 kcal mol-1, in good agreement with Nguyen and Fitzpatrick's theoretically predicted value of 158 ± 3 kcal mol-1. The heats of formation of HP2-, HP2+, HPPH, FP2-, and FPPH have been estimated from the experimentally determined hydride, proton and fluoride affinities of P2 and from the gas-phase acidities of HPPH and FPPH.
A selected ion flow tube study of the reactions of the PHn+ ions (n=0to 4) with several molecular gases at 300 K
Smith, David,McIntosh, Bruce J.,Adams, Nigel G.
, p. 6213 - 6219 (2007/10/02)
The reactions of ions in the series PHn+ (n=0 to 4) have been studied at 300 K with CH3NH2, PH3, NH3, CH3CCH, H2S, C2H4, CH3OH, COS, C2H2, O2, H2O, CH4, HCN, CO2, CO, and H2 using a selected ion flow tube (SIFT) apparatus.The majority are fast binary reactions, the measured rate coefficients, k, being close to the respective collisional values, and for reactions involving polyatomic reactant molecules multiple product ions are observed.Most reaction mechanisms are represented in this large number of reactions including charge transfer, proton transfer, atomabstraction and especially evident is phosphorus atom insertion in which product ions such as HnPN+, HnPO+, HnPS+ and HnCmP+ are formed.The reactions of the PHn+ ions (n=0 to 2) with CO2, CO, and H2 proceed by the process of ternary association except for the P+ reaction with CO2, in which PO+ is formed in a fast binary reaction PH4+ reacts only with CH3NH2 and NH3 by fast proton transfer, a process which is always rapid when it is exothermic.Upper limits to the heats of formation of HPO+, H2PO+, PC2H2+ and HCP have also been deduced from their observation as products of some of the reactions.
The Tetrahydridosulfonium Dication, H4S2+. Hydrogen-Deuterium Exchange of DH2S+ in FSO3D:SbF5 and D2HS+ in FSO3H:SbF5 and Theoretical Calculations
Olah, George A.,Prakash, G. K. Surya,Marcelli, Michael,Lammertsma, Koop
, p. 878 - 880 (2007/10/02)
Isotopomeric hydridosulfonium ions undergo proton/deuterium exchange in (Magic Acid) FSO3D*SbF5 and FSO3H-SbF5-SO2 solutions as monitored by 1H NMR spectroscopy.The rate of exchange increases with the increase in acidity of the superacidic medium, indicat
Ion-Molecule Reactions Involving H3O+, H2O+, and OH+ at Thermal Energy
Shul, R. J.,Passarella, R.,DiFazio, L. T.,Keesee, R. G.,Castleman, A. W.
, p. 4947 - 4951 (2007/10/02)
The rate coefficients for a variety of reactions involving OH+, H2O+, and H3O+ with CS2, H2S, SO2, NO, NO2, N2O, N2, O2, CH4, CO2, CO, NH3, and H2 are obtained with a selected ion flow tube.The product channels include proton transfer, charge transfer, atom abstraction, and association.Most of the reaction rates are fast and have high reaction efficiencies.Reaction of OH+ with NO2 is found to produce both NO2+ and NO+; even though both reaction channels are also exothermic with H2O+, only NO2+ is produced.H3O+ is found to undergo association reactions with SO2 and N2O and H2O+ does so with CO2 and N2O.The reaction of H2O+ with N2O also involves a second-order process in addition to the association pathway.
An experimental survey of the reactions of NHn+ ions n=0 to 4) with several diatomic and polyatomic molecules at 300 K
Adams, Nigel G.,Smith, David,Paulson, John F.
, p. 288 - 297 (2007/10/02)
A study has been made of the binary reactions at 300 K in a SIFT apparatus of the ions N+, NH+, NH2+, NH3+, and NH4+ with CH3NH2, NO, NH3, H2S, CH3OH, H2CO, COS, O2, H2O, CH4, CO2, CO, H2, and N2.The N+, NH+, and NH2+ reactions are generally fast, their rate coeeficients being close to the collisional limit, and multiple product channels result, especially for reactions with the polyatomic molecules.Several reaction mechanisms are apparent, including charge transfer, proton transfer, and H-atom abstraction, although it is argued that many of the reactions preceed via a short-lived, ion-molecule complex which separates along the observed reaction channels.The NH3+ ions are seen to be generally less reactive than the lesser hydrogenated ions, the product of most of the reactions being NH4+ ions which do not undergo binary reactions with any of the molecules (except CH3NH2) but rather undergo ternary association reactions with a few of them.A few measurements were mede using the deuterated analogs ND+, ND2+, ND3+, and ND4+ in order to shed further light on some of the reaction mechanisms.
Acidity, basicity, and gas-phase ion chemistry of hydrogen selenide by ion cyclotron resonance spectroscopy
Dixon, David A.,Holtz, David,Beauchamp
, p. 960 - 963 (2008/10/08)
Reaction pathways, product distributions, and rate constants have been determined for the gas-phase ion-molecule reactions of H2Se by ion cyclotron resonance spectroscopy. Hydrogen selenide fragment ions condense with neutral H2Se, e
