Multiply charged ions

An almost completely different area of interests is related with all kinds of multiply charged ions, and the Prague team can be considered as one of the worldwide leading players in this competitive field, as demonstrated by invitations to review articles and highlights (e.g. Journal of Physical Chemistry A 1999 and Angewandte Chemie - International Edition 2004).

As an example for the information gained from these experimental studies, the following Figure shows the evaluation of so-called Q_min values associated with transition of mono- into dications in charge-stripping experiments. The Q_min value is derived from the high-energy onsets of the singly and doubly charged ion on the kinetic energy scale and provides a unique measure for the determination of second ionization energies of mass-selected species.

The group also participated in a very successful European Research Network (MCInet) on this topic. Recently, in summarizing the research efforts of the network, a comprehensive study of CHX²⁺ dications was performed, which led to a new reactivity concept for bimolecular reactions of gaseous dications (Chemistry - A European Journal 2006). Further notable achievements are two recent contributions which for the first time open realistic perspectives for the growth of larger hydrocarbon molecules under extreme conditions such as they exist in interstellar space (Journal of American Chemical Society 2006) and Physical Chemistry Chemical Physics 2007a).

The new results about bimolecular reactions of molecular dications have just recently been reviewed (Physical Chemistry Chemical Physics 2007b). Further, a general concept for the bimolecular reactivity of molecular dications A²⁺ with a neutral species B has been proposed which includes not only electron- as well as proton-transfer processes, but also bond-forming reactions under maintenance of the two-fold charge (e.g. channel to C²⁺ + D in the following Figure).