Resumen: The influence of both the skeleton and substituents of the diphosphane in the photophysical properties of [Cu(NHC)(P^P)]PF6 TADF-phosphorescent emitters is investigated [NHC = Bz-Im-2-XPy (X = H, Cl)]. The study reveals that optimization of the diphosphane structure can boost quantum yields to as high as 85% using carbenes with simple structural frameworks or substituent wings. Remarkably, the diphosphane skeleton emerges as the most influential factor for controlling the quantum yield (Φ). None of the ΔE(S1-T1) energy gap, steric factors (buried volume percentage), or T1 energy alone seem to govern the observed Φ. These insights reveal new avenues for achieving high-performance TADF emitters through ligand engineering. Idioma: Inglés DOI: 10.1021/acs.inorgchem.5c03511 Año: 2025 Publicado en: Inorganic Chemistry 64, 43 (2025), 21541-21550 [10 pp.] ISSN: 0020-1669 Financiación: info:eu-repo/grantAgreement/ES/DGA-FSE/A07_23R Financiación: info:eu-repo/grantAgreement/ES/MICINN AEI/PID2022-136861NB-I00 Financiación: info:eu-repo/grantAgreement/ES/MICINN/TED2021-130447B-I00 Tipo y forma: Article (Published version) Área (Departamento): Área Química Inorgánica (Dpto. Química Inorgánica)