Dissociation reactions of free tetrapyridinium tetracations and of their catenanes.
Electrospray ionization from methanolic solution can be used for the generation of the free cyclophane tetracations 1(4+) -3(4+) from the corresponding hexafluorophosphates. In the idealized gas phase, these tetracations are long-lived and can easily be handled for further spectroscopic studies. Collision-induced dissociation of the free tetracations brings about charge separation via cleavage of the pyridinium bonds, leading to a pair of dications. Subsequently, these dications undergo another charge separation reaction to finally afford singly charged cations. In addition to the free tetracations, also the corresponding trications having one PF6- counterion are examined. Collision-induced dissociation of the trications leads to a formal substitution reaction concomitant with C-F bond formation. Further, the catenanes of the tetracations 1(4+) -3(4+) with bis-p-phenylene-34-crown-10 (4) are investigated. For the parent compound 1, also the gas-phase infrared spectrum is reported for the first time.
Roithová
Jana
J
Institute of Organic Chemistry and Biochemistry, Flemingovo nAm. 2, 16610 Prague 6, Czech Republic.
Milko
Petr
P
Ricketts
Claire L
CL
Schröder
Detlef
D
Besson
Thierry
T
Dekoj
Václav
V
Belohradský
Martin
M