Antiferromagnetic coupling in copper(II)porphyrin dimers linked by copper(II) or palladium(II) ion

The synthesis of porphyrin dimers linked by metal ions is described and the X-ray structure of two new dimers is presented. As previously shown for diamagnetic metal ions, strong electronic interactions between the individual subunits were observed. Antiferromagnetic coupling between copper(II)porphyrins linked by palladium(II) or copper(II) ions was studied by EPR and SQUID measurements. For the palladium(II)-linked dimer, the very small antiferromagnetic coupling was estimated by EPR measurements ([Formula: see text] <-1 cm[Formula: see text]. For the trinuclear-copper(II)-linked dimer, a large antiferromagnetic coupling between the copper(II) ions was measured. In this trinuclear compound, the linking copper(II) ion is used as a relay to increase the interaction between the two copper(II)porphyrins.

A post-cyclotetramerization strategy towards novel binuclear phthalocyanine dimers

A new and effective post-cyclotetramerization strategy was developed for the first time towards the synthesis and isolation of a new type of homo/heterodinuclear π-conjugated phthalocyanine dimer sharing one common pyrazine moiety.

Heteroleptic Tetrapyrrole-Fused Dimeric and Trimeric Skeletons with Unusual Non-Frustrated Fluorescence

Phthalocyanine (Pc) and porphyrin (Por) chromophores have been fused through the benzo[α]pyrazine moiety, resulting in unprecedented heteroleptic tetrapyrrole-fused dimers and trimers. The heteroleptic tetrapyrrole nature has been clearly revealed based on single-crystal X-ray diffraction analysis of the zinc dimer. Electrochemical analysis, theoretical calculations, and time-resolved spectroscopic results disclose that the two/three-tetrapyrrole-fused skeletons behave as one totally π-conjugated system as a result of the strong conjugative interaction between/among the tetrapyrrole chromophores. In particular, the effectively extended π-electron system through the fused-bridge induced strong electronic communication between the Pc and Por moieties and large transition dipole moments in the Pc-Por-fused systems, providing high fluorescence quantum yields (>0.13) and relatively long excited state lifetimes (>1.3 ns) in comparison with their homo-tetrapyrrole-fused analogues.