1.1 Porphyrins - Friedrich-Alexander-Universität Erlangen-Nürnberg

3 Discussion and Results
peak at m/z = 1369 correspondent to [M] + in the MALDI-TOF spectrum without any
fragments.
The 1 H NMR spectrum shows up as sum of both precursors’ spectra in most areas like it is
depicted in Figure 50. Thereby, the conjugation caused hardly any shifts of resonance signals
in the cycloketo-porphyrin part while such shifts are clearly observed for the chlorin moiety
most pronounced for protons situated close to the setup linkage.
126
CDCl 3
9 8 7 6 5 4 3 2 1 0 δ [ppm] -2
Figure 50. Comparison of the 1 H NMR spectrum of obtained conjugate 94 (center, black)
with those of precursor cycloketo-porphyrin 92 (top, blue) and methyl pyropheophorbide a
Me-33 (bottom, green) whereat arrows indicate shifts of signals. All measurements were
conducted at 400 MHz in CDCl3 at rt.
Involving 1 H 1 H COSY data and the corresponding precursor data, the spectra could be fully
assigned (see paragraph 6.2.6.10) while it is conspicuous that not only the signals close to
the coupling site are affected and shifted but also resonances of more distantly lying protons
like e.g. those for the three aromatic methyl groups within the chlorin moiety. They are
detected at 3.16, 3.37 and 3.61 ppm for Me-33 while they are found at 2.74, 3.19 and
3.38 ppm in the spectrum of conjugate 94. Furthermore, changes are found concerning
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92
94
Me-33