Ruthenium(II) complexes of meso-tetrakis(4-cyanophenyl)porphyrin

A novel synthesis is presented for the meso-tetrakis(4-cyanophenyl)porphyrin complex Ru(T-pCN-PP)(CO)(H2O), the first Ru complex with this long-known porphyrin; compared to standard methods reported for other porphyrin analogues via Ru3(CO)12, extra steps involving addition of pyridine (Py) and its subsequent removal as [HPy+]Cl− are required. The Py breaks down coordination polymers (as yet uncharacterized) formed via the peripheral p-cyanophenyl moiety; these materials may offer potential as porphyrin-based supramolecular solids. Removal of the CO by photolysis in MeCN solution generates Ru(T-pCN-PP)(MeCN)2, but attempts to make the bis(thiol) analogues from this precursor were unsuccessful, again due to formation of polymeric species.

The illustrated Ru complexes of meso-tetrakis(4-cyanophenyl)porphyrin are described; the metallation process is lengthy and non-standard because of complications involving coordination through the peripheral p-cyano group(s). Attempted synthesis of the bis(thiol) species is unsuccessful because of related ‘polymer’ formationFigure optionsDownload as PowerPoint slideHighlights
► First synthesis of a Ru complex containing meso-tetrakis(4-cyanophenyl)porphyrin.
► Novel synthesis of Ru(T-pCN-PP)(CO)(H2O).
► Photoloytic synthesis of Ru(T-pCN-PP)(MeCN)2
► Likely formation of Ru–porphyrin-based supramolecular solids.