Marriage of an N-Fused and a Regular Porphyrin in a Cofacial Ligand System

We present a straightforward synthetic route which allowscofacialstacking of N-fused porphyrins and regular porphyrins via an o-substitutedphenylene linker. The protocol comprises a crucial Suzuki-Miyauracross-coupling reaction to introduce the phenyl moiety at the tri-pentacyclicring of the N-fused porphyrin, paving the way to the first arrangementthat is capable of holding an N-fused porphyrin and a regular porphyrinin spatial proximity. The ligand system was obtained with a 0.77%yield in five steps, starting from pyrrole and benzaldehyde. The dimericligand was investigated for further insights into sterical properties,employing inter alia ion-mobility spectrometry, DFT calculations,and metal coordination reactions. The molecular species were characterizedby H-1 NMR, UV-vis, IR, high-resolution mass spectrometry,and trapped ion-mobility measurements. The latter suggests that theligand system can stabilize two atoms of the same metal in differentoxidation states, such as in an Mn(I)Mn(III) complex.

Automated summary

We have developed a synthetic route to achieve cofacial stacking of N-fused porphyrins and regular porphyrins using an o-substituted phenylene linker. This approach involves a crucial Suzuki-Miyaura cross-coupling reaction to introduce a phenyl moiety into the tri-pentacyclic ring of the N-fused porphyrin, enabling the formation of a spatial arrangement that can hold both N-fused porphyrin and regular porphyrin in close proximity. The resulting ligand system was obtained with a 0.77% yield in five steps and was characterized using various techniques.