Open AccessObservation of phenyl-fused porphyrinoids during the ESI mass spectrometric analysis of meso-pentafluorophenyl-substituted porphyrin and corrole
Author(s) -
Kimberly S. F. Lau,
Martin Sadı́lek,
Martin Gouterman,
Gamal Khalil,
Christian Brückner
Publication year - 2006
Publication title -
journal of the american society for mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.961
H-Index - 127
eISSN - 1879-1123
pISSN - 1044-0305
DOI - 10.1016/j.jasms.2006.06.004
Subject(s) - chemistry , porphyrin , fragmentation (computing) , mass spectrometry , electrospray ionization , aryl , corrole , radical , regioselectivity , ionization , computational chemistry , photochemistry , stereochemistry , organic chemistry , chromatography , ion , alkyl , computer science , catalysis , operating system
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(F)PP and T(F)PC are reported. The fragmentation patterns of TPP and TPC show the expected loss of meso-aryl radicals. Analyzing the meso-pentafluorophenyl substituted analogs T(F)PP and T(F)PC, 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-beta-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.