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The α-effect-enhanced nucleophilicity of an anion with a lone pair of electrons adjacent to the attacking atom-has been well documented in solution; however, there is continuing disagreement about whether this effect is a purely solvent-induced phenomenon or an intrinsic property of the α-nucleophiles. To resolve these discrepancies, we explore the α-effect(More)
Chemical-ionization mass spectrometry (CIMS) using flow reactors is an emerging method for on-line monitoring of trace concentrations of organic compounds in the gas phase. In this study, a flow-reactor CIMS instrument, employing the H(3)O(+) cation as the ionizing reagent, was used to simultaneously monitor several volatile metabolic products as they are(More)
A rapid and highly sensitive method for the detection of formaldehyde utilizing selected ion flow tube-chemical ionization mass spectrometry is reported. Formaldehyde in aqueous biological samples is preconcentrated by distillation and directly analyzed using gas-phase thermal energy proton transfer from H30+; this procedure can be performed in 30 min. The(More)
Selected ion flow tube-chemical ionization mass spectrometry was used to measure formaldehyde levels in human breast cancer cells in comparison with levels in cells treated with the antitumor drugs doxorubicin (DOX) and daunorubicin (DAU) and the daunorubicin-formaldehyde conjugate Daunoform (DAUF). The measurement was performed on cell lysates and showed(More)
A selected ion flow tube-chemical ionization mass spectrometric method is presented for the first determination of acrolein metabolically produced in biological tissues. Acrolein in aqueous samples (2.5 ml) is preconcentrated by distillation and directly analyzed using gas-phase proton transfer from H3O+. This method provides sensitive detection of acrolein(More)
The 364-nm photoelectron spectrum of pyrrolide anion, prepared by deprotonation of pyrrole, has been measured. The electron affinity (EA) of pyrrolyl radical has been determined to be 2.145 ( 0.010 eV. Harmonic vibrational frequencies of 925 ( 65, 1012 ( 25, and 1464 ( 20 cm-1 are observed in the spectrum of the A2 ground state of pyrrolyl. This spectrum is(More)
We present a determination of ∆fH298(HOO) based upon a negative ion thermodynamic cycle. The photoelectron spectra of HOOand DOOwere used to measure the molecular electron affinities (EAs). In a separate experiment, a tandem flowing afterglow-selected ion flow tube (FA-SIFT) was used to measure the forward and reverse rate constants for HOO+ HC≡CH a HOOH +(More)
Methyl, methyl-d(3), and ethyl hydroperoxide anions (CH(3)OO(-), CD(3)OO(-), and CH(3)CH(2)OO(-)) have been prepared by deprotonation of their respective hydroperoxides in a stream of helium buffer gas. Photodetachment with 364 nm (3.408 eV) radiation was used to measure the adiabatic electron affinities: EA[CH(3)OO, X(2)A' '] = 1.161 +/- 0.005 eV,(More)
The 351.1 nm photoelectron spectrum of the peroxyformate anion has been measured. The photoelectron spectrum displays vibronic features in both the 2A'' ground and 2A' first excited states of the corresponding radical. Franck-Condon simulations of the spectrum show that the ion is formed exclusively in the trans-conformation. The electron affinity (EA) of(More)