Photophysical data for complexes [Ln.1–4]+ (10 mM HEPES, pH 7.0).
| Complex | λ max/nm | ε/mM−1 cm−1 | ϕ em a/% | τ(H2O)/ms | τ(D2O)/ms | q b |
|---|---|---|---|---|---|---|
| [Eu.1]+ | 332 | 12.5 | 7.0 | 0.48 | 1.39 | 1.2 |
| [Eu.2]+ | 330 | 7.7 | 6.5 | 0.56 | 1.22 | 0.8 |
| [Eu.3]+ | 328 | 14.0 | 9.6 | 0.46 | 0.99 | 1.0 |
| [Eu.4]+ | 332 | 10.1 | 8.3 | 0.54 | 1.28 | 0.9 |
| [Tb.1]+ | 332 | 4.7 | n.d. | — | — | — |
a
Overall luminescence quantum yields were measured using a previously reported 8-benzyloxyquinoline functionalized DO3A Eu(iii) complex (ϕem = 6%),39 and rhodamine 101 in acidified ethanol, as standards. Quantum yields have an estimated maximum uncertainty of ±20%.
b
Values of hydration state, q (±20%) were derived using the modified Horrocks equation.40