1.1 Porphyrins - Friedrich-Alexander-Universität Erlangen-Nürnberg

Normalized absorption
1.0
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0
91
92
93
300 400 500 600 λ[nm] 800
Normalized fluorescence
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Discussion and Results 3
650 700 750 800 λ [nm] 900
Figure 49. Normalized absorption (left) and fluorescence spectra (right) for 93 in comparison
to nitro and free amino compound 91 and 92 as solution in DMF. For fluorescence:
excitation at 540 nm (solid lines) and at 588 nm (dashed lines), respectively.
The obtained results perfectly corroborate the previously setup assumptions. Firstly, amino
system 92 behaves like a usual amine and can be coupled to carbon acid derivatives via
standard protocols and secondly, the amide structure resulting from that coupling has
photophysical characteristics resembling structural analogs 53 and 91 having a t-butyl or
nitro substituent in 15 4 position. Hence, the downgrading of the photophysical parameters
caused by the free amine can be almost fully suppressed by amide formation.
Based on those findings, several possible strategies can be thought of to develop novel
photoactive materials for PDT applications. Those will be discussed next.
91
92
93
123