Table 1.
PC | λmax,abs .(nm)[a] |
ε (M−1cm−1) |
λmax,S1 em. (nm)[b] |
Φf (%) |
ES1,exp. (eV)[c] |
ET1,calc.
(eV)[d] |
ET1,77 K (eV)[c,e] |
E1/2 (2PC●+/1PC) (V vs. SCE)[f] |
E0*S1,exp. (2PC●+/1PC*) (V vs. SCE)[g] |
E0*T1,exp. 77 K (2PC●+/3PC*) (V vs. SCE)[e,g] |
E0*T1,calc. (2PC●+/3PC*) (V vs. SCE)[d] |
---|---|---|---|---|---|---|---|---|---|---|---|
1 | 361 | 46,300 | 487 | 0.3 | 2.55 | 2.41 | 2.34 | 0.76 | −1.79 | −1.58 | −1.86 |
2 | 340 | 38,600 | 509 | 0.1 | 2.44 | 2.36 | 2.33 | 0.71 | −1.73 | −1.62 | −1.94 |
3 | 382 | 44,300 | 458 | 83 | 2.71 | 2.43 | 2.39 | 0.90 | −1.81 | −1.49 | −1.69 |
4 | 360 | 49,800 | 453 | 3.8 | 2.74 | 2.30 | 2.34 | 0.77 | −1.98 | −1.57 | −1.77 |
5 | 361 | 31,500 | 443 | 27 | 2.80 | 2.29 | 2.35 | 0.76 | −2.04 | −1.59 | −1.75 |
6 | 363 | 43,100 | 444 | 70 | 2.79 | 2.28 | 2.34 | 0.75 | −2.04 | −1.59 | −1.78 |
7 | 355 | 50,100 | 535 | 8.2 | 2.32 | 2.39 | 2.37 | 0.82 | −1.50 | −1.55 | −1.78 |
Absorption wavelength measured using ultraviolet-visible spectroscopy in DMF.
Emission wavelength measured using steady-state fluorescence spectroscopy in DMF.
Energies were calculated using the maximum wavelength of emission.
DFT calculations performed at uM06/6–311+Gdp/uM06/6–31+Gdp level of theory with CPCM-described solvation in aqueous solvent.
Spectral emission measured at 77 K after 1 ms gate-delay.
All measurements were performed in a 3-compartment electrochemical cell with an Ag/AgNO3 reference electrode in MeCN (0.01 M) and 0.1 M NBu4PF6 electrolyte solution with DMF analyte solution. Platinum was used at the working and counter electrodes.
Excited-state redox potentials were calculated using energies estimated from the maximum wavelength of singlet or triplet emission and the experimentally measured E1/2; E0*S1,exp.= E1/2 − ES1,exp. and E0*T1, exp. 77K = E1/2 − ET1,77K.