Abstract
The results of ESI(+) and ESI(−) mass spectrometry/mass spectrometry investigations of
meso-tetrakisphenylporphyrin (
TPP) and
meso-trisphenylcorrole (
TPC) in comparison with their
meso-tetrakis(pentafluorophenyl)-substituted analogs
T
FPP
and
T
FPC
are reported. The fragmentation patterns of
TPP and
TPC show the expected loss of
meso-aryl radicals. Analyzing the
meso-pentafluorophenyl substituted analogs
T
FPP
and
T
FPC
, we found ESI(−) to be an excellent ionization mode. Rich and well-defined HF-elimination fragmentation patterns unique to the presence of
meso-tetrafluorophenyl groups and evocative for the formation of fragments with direct covalent
o-phenyl-to-β-linkages are observed. A computation of the feasibility and relative energies of the resulting species corroborates the interpretation of the experimental findings. The computations indicate the presence of cooperative interactions between the linkages that direct the linkage formations to occur in a unidirectional fashion. MS/MS/MS experiments also provide indications for the regioselectivity of the fusions. Our observations further detail earlier reports of similar HF-eliminations and allow a generalization of the findings. The results presented may also point to strategies towards the bulk synthesis of novel porphyrinoid structures.