摘要： In a previous investigation, it was shown that [Cu(tpym)(PPh3)]PF6 1 with tpym = tris(2-pyridyl)methane represents a deep blue emitter (λmax = 466 nm) though with a low emission quantum yield ΦPL if doped in a polymer (7%) or dissolved in a ?uid solvent (?1%). In this study, we present new tripod compounds with [Cu(tpym)(P(o-tol)3)]PF6 2 and [Cu(tpym)(P(o-butyl-ph)3)]PF6 3 with sterically demanding ligands: P(o-tol)3 = tris(ortho-tolyl)phosphine and P(o-butyl-ph)3 = tris(ortho-n-butylphenyl)phosphine. These compounds show high emission quantum yields even in a ?uid solution (dichloromethane) reaching a benchmark value for 3 of ΦPL = 76%. This becomes possible due to the speci?c design of rigidifying the complexes. Importantly, the deep blue emission color is maintained or even further blue shifted to λmax = 452 nm (compound 3 powder). Compound 2 is characterized photophysically in detail. In particular, it is shown that the lowest excited triplet state T1 experiences very e?cient spin–orbit coupling (SOC). Accordingly, the phosphorescence decay rate is as large as 5 × 104 s?1 (20 μs) belonging to the fastest T1 → S0 transition values (shortest decay times) reported so far. Investigations down to T = 1.5 K reveal a large total zero-?eld splitting (ZFS) of 7 cm?1 (0.9 meV). Although thermally activated delayed ?uorescence (TADF) grows in at T ≥ 160 K, the phosphorescence of 2 still dominates (60%) over TADF (40%) at ambient temperature. Thus, the compound represents a singlet harvesting-plus-triplet harvesting material, if applied in an OLED.