Luminescence from open-shell, first-row transition metal dipyrrin complexes

Several first-row transition metal complexes of the 1,9-bis(2 ',4 ',6 '-triphenylphenyl)-5-mesityl dipyrrinato ligand and its tetrahalogenated analogues have been synthesized and their luminescence spectra obtained. The protonated ligands, as well as the Li(i), Mn(ii), Cu(i), Cu(ii), and Zn(ii) chelates show appreciable luminescence, despite the paramagnetism of the Mn(ii) and Cu(ii) ions. Fluorescence quantum yields (phi(F)) as high as 0.67 were observed for the zinc complex. Luminescence was partially quenched by the introduction of heavy halogens to the backbone of the ligand, as well as by the introduction of paramagnetic metal ions. Room-temperature, solution state phosphorescence was observed from the halogenated dipyrrinato lithium salts, as well as from the non-halogenated Mn(ii) complex.

Automated summary

In this study, several first-row transition metal complexes with 1,9-bis(2',4',6'-triphenylphenyl)-5-mesityl dipyrrinato ligand and its tetrahalogenated analogues were synthesized, and their luminescence spectra were obtained. The protonated ligands, as well as the Li(i), Mn(ii), Cu(i), Cu(ii), and Zn(ii) chelates exhibited appreciable luminescence, with zinc complex showing the highest fluorescence quantum yields. The introduction of heavy halogens to the ligand backbone and paramagnetic metal ions partially quenched luminescence. Room-temperature, solution state phosphorescence was observed from the halogenated dipyrrinato lithium salts, as well as from the non-halogenated Mn(ii) complex.