Hybrid Inorganic–Organic Complexes of Zn, Cd, and Pb with a Cationic Phenanthro-diimine Ligand

[Image: see text] The phosphonium-decorated phenanthro-imidazolyl pyridine ligand, LP(+)Br, readily reacts with zinc(II) and cadmium(II) bromides to give inorganic–organic zero-dimensional compounds [LP(+)ZnBr(2)](2)[ZnBr(4)] (1) and [(LP(+))(2)Cd(2)Br(4)][CdBr(4)] (2), respectively, upon crystallization. These salts are moderately fluorescent in the solid state under ambient conditions (λ(em) = 458 nm, Φ(em) = 0.11 for 1; λ(em) = 460 nm, Φ(em) = 0.13 for 2). Their emission results from spin-allowed electronic transitions localized on the organic component with the negligible effect of [MBr(4)](2–) and MBr(2) units. Contrary to ionic species 1 and 2, lead(II) bromide affords a neutral and water-stable complex [(LP(+))(2)Pb(3)Br(8)] (3), showing weak room-temperature phosphorescence arising from spin–orbit coupling due to the heavy atom effect. The emission, which is substantially enhanced for the amorphous sample of 3 (λ(em) = 575 nm, Φ(em) = 0.06), is assigned to the intraligand triplet excited state, which is a rare phenomenon among Pb(II) molecular materials.