Dual phosphorescent emissions from conformers of iridium complex rotors.

Authors :: Hsu YT
Bhagani C
Aguilar JA
Fox MA
Yufit D
Davidson RJ
Beeby A
Source :: Dalton transactions (Cambridge, England : 2003) [Dalton Trans] 2024 Nov 05; Vol. 53 (43), pp. 17518-17524. Date of Electronic Publication: 2024 Nov 05.
Publication Year :: 2024
Abstract: The chiral iridium rotors Ir(ppy) <subscript>2</subscript> (pyX)Cl (X = CC-SiR <subscript>3</subscript> , R = alkyl) remarkably contain two distinct rotational conformers in the ground (S <subscript>0</subscript> ) and excited (T <subscript>1</subscript> ) states that can be detected by NMR and emission measurements respectively at variable temperatures. The observed phosphorescent emissions, vibronic (involving L = ppy) and broad (L = pyX), arise from different triplet ligand to metal charge transfers from the two rotational conformers at distinct <superscript>3</superscript> MLCT excited states. Both conformers exist in these Ir(ppy) <subscript>2</subscript> (pyX)Cl rotors due to the electron-withdrawing, conjugated substituent X.