Schematic drawings of our source for bringing parent anions of involatile molecules into the gas phase. It consists of a sample-coated graphite bar from which molecules are desorbed when irradiated by low intensity infrared pulses, a photoemitter from which electrons are emitted when irradiated by high intensity visible pulses, and a pulsed gas valve which provides a jet of inert gas. Two versions are shown, (a) with a low work function metal as a photoemitter and (b) with an yttria disk as a photoemitter.
A mass spectrum showing the cytidine parent anion. It was one of seven nucleoside parent anions generated by the source described in the text and shown schematically in Fig. 1.
The photoelectron spectra of the seven nucleoside parent anions studied in this work. These spectra were recorded with photons.
Comparison of the photoelectron spectra of the anions of deoxythymidine, deoxycytidine, and deoxyadenosine with the theoretically predicted values of and VDE for these same species. The symbols, and †, denote values from the calculations of Schaefer et al. and Sevilla et al., respectively. Down-going arrows indicate the location of the VDE value on each spectrum. Solid vertical sticks denote predicted VDE values, while dotted and dashed vertical sticks denote predicted values.
Experimental and theoretical values of and VDE for nucleosides and their anions, respectively. Error bars for expt. VDE values are , while those for expt. are .
Article metrics loading...
Full text loading...