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

ABSTRACT: 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⁺ZnBr₂]₂[ZnBr₄] (1) and [(LP⁺)₂Cd₂Br₄][CdBr₄] (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 [MBr₄]^2- and MBr₂ units. Contrary to ionic species 1 and 2, lead(II) bromide affords a neutral and water-stable complex [(LP⁺)₂Pb₃Br₈] (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.

SUBMITTER: Temerova D 

PROVIDER: S-EPMC9727735 | biostudies-literature | 2022 Dec

REPOSITORIES: biostudies-literature