engleski

The niobium and tantalum riddle: gas-phase monocation reactions with pyrene and pyrene-D10

Metal monocation gas-phase reactions with pyrene (Py) have been investigated. Of those cations which bind Py by abstraction of two hydrogen atoms, there are two subgroups of which Nb+ and Ta+ are the most striking and puzzling representatives. The Ta+-like group binds three Py units consecutively, each by expulsion of two hydrogen atoms, whereas the Nb+ group binds four Py units ; however, in this latter case, the second Py attachment occurs without the expulsion of any hydrogen. When perdeuterated Py-D10 is used, the Ta+ group behavior is unaffected but the Nb+ group now exhibits a considerable degree of Py attachment in which no deuterium atoms are lost in the first reaction step. We will attempt to explain this behavior using the results of reactions of Nb+ and Ta+ with Py in a Fourier transform mass spectrometer (FTMS).

gas phase reactions; FTMS; metal monocation ligation by PAHs; deuterium isotope effect

nije evidentirano