Access to hybrid supramolecular salen–porphyrin assemblies via a selective in situ transmetalation–metalation self-assembly sequence

New supramolecular hybrid assemblies have been selectively prepared starting off with stoichiometric mixtures of pyridine-tagged Zn(salphen) and non-metalated porphyrin ligands in the presence of suitable metal acetates. This one-pot procedure leads to in situ transmetalation of the salen unit, metalation of the porphyrin ligand by the released Zn(OAc)2 and subsequent heterometallic assembly formation between the metallosalen and metalloporphyrin components via Zn–Npyr coordination motifs. The reactions were followed by NMR spectroscopy and MALDI-TOF mass spectrometry, and for one of the Zn(salphen) building blocks the X-ray molecular structure is reported.

Graphical abstractA new approach is described for the formation of hybrid heterobimetallic assemblies based on metallosalen and metalloporphyrin scaffolds. These structures are obtained via a three-step sequence that involves transmetalation of the metallosalen unit, subsequent metalation of the free base porphyrin and self-assembly between the transmetalated salen complex and the metalloporphyrin.Figure optionsDownload full-size imageDownload as PowerPoint slide