Mass spectra of C5H8 isomers

Electronic spectra of C4H3Cl+ isomers

Two experimental methods were applied to identify the structure and electronic transitions of C4H3Cl þ isomers. The first is a direct absorption technique where mass-selected ions are embedded in 6K neon matrices using a mass-selected ion beam and absorption spectra of different C4H3Cl þ isomers were thus observed. The second is a gas phase method on ions which have been collisional cooled with...

POSITIVE AND NEGATIVE ION MASS SPECTRA OF RING - SUBSTITUTED NITROBENZENES

The 70 ev positive and negative ion mass spectra of ring-substituted nitrobenzenes were studied. The influence of the substituent group on the fragmentation modes of the molecular ions is discussed. The effect of pressure in the formation of negative ions was also studied. As expected, the ratio of fragment ions to negative molecular ions decreased with increasing pressure in ion source.

Substitution effects on the absorption spectra of nitrophenolate isomers.

Charge-transfer excitations highly depend on the electronic coupling between the donor and acceptor groups. Nitrophenolates are simple examples of charge-transfer systems where the degree of coupling differs between ortho, meta and para isomers. Here we report the absorption spectra of the isolated anions in vacuo to avoid the complications of solvent effects. Gas-phase action spectroscopy was ...

Modelling CDA mass spectra

We present the initial results from a simulation of ion behaviour within Cassini’s cosmic dust analyser (CDA) instrument, using an inhouse ion dynamics code. This work is to enable and enhance the detailed interpretation of dust impact ionisation mass spectra returned from the Saturnian system. Early work has already provided insights into the properties of the impact plasma in both lowand high...

accurate-mass spectra