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ISSN 1998-9539

The Peculiarities of Ionization, Fragmentation and Association (Macrobicyclization) of Pseudoclathrochelate tris-Pyrazoloximates of Zinc(II), Cobalt(II), Iron(II) and Manganese(II) in the LDI Mass Spectra

Svitlana V. Kats,a Olga V. Severynovskaya,b Oleg A. Varzatskii,c Ekaterina G. Lebed,d@ and Vadim A. Pavlenkoa
aTaras Shevchenko National University of Kyiv, 01601 Kyiv, Ukraine
bChuiko Institute of Surface Chemistry of National Academy of Sciences of Ukraine, 03164 Kyiv, Ukraine
cVernadskii Institute of General and Inorganic Chemistry of the National Academy of Sciences of Ukraine, 03680 Kyiv, Ukraine
dNesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences, 119991 Moscow, Russia
@Corresponding author E-mail:
DOI: 10.6060/mhc150979l
Macroheterocycles 2015 8(3) 314-320
Main pathway of the ionization of the complexes [M(HPzOx)3(BC6H5)]Cl is heterolytic dissociation of these ionic associates giving chloride ions and boron-capped tris-pyrazoloximate cations [M–Cl]+. The latters are thermodynamically unstable due to the destraction of a pseudomacrobicyclic framework and undergo the further fragmentation leading to the corresponding species and the cluster ions. Such a dissociative type of the fragmentation suggests a substantial stability of the coordination M−N bonds. The spectra of the oximehydrazonate macrobicyclic complexes with similar structure contain the peaks of the corresponding clathrochelate cations; and to their tris-dioximate analogs, giving the characteristic ion-molecular associates with alkali metal cations. The LDI mass spectra of the boron-capped tris-pyrazoloximate pseudoclathrochelate do not contain the peaks of the molecular ions and their associates with alkali metal ions, whereas the detachment of cross-linking chloride counterion is the main pathway of their fragmentation. The non-macrocyclic tris-pyrazoloximate formed particles are unstable and either undergo the fragmentation with an elimination of one of the three ribbed chelate fragments, or, as tripodal semiclathrochelate tris-pyrazol ligands, form the unusual binuclear complexes by their coordination to the corresponding metal ion.



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