TABLE 4.
Calculated Properties of the Two Lowest-Lying Excited Singlet States of Fucoxanthin
theoretical method | μg S0 (D) |
ΔE (eV) |
fosc |
ΔE (eV) |
fosc |
Δμ ←S0(D) |
Δμ ←S0(D) |
||||
---|---|---|---|---|---|---|---|---|---|---|---|
MNDOCIa | AM1 | Slater | 8.461 | 2.628 | 0.471 | 2.728 | 2.532 | + 8.755 | −2.365 | ||
MNDOCIb | AM1 | Slater | 8.461 | 2.541 | 0.158 | 2.690 | 2.697 | + 5.969 | + 0.820 | ||
MNDOCI+c | AM1 | Slater | 8.453 | 2.432 | 0.022 | 2.712 | 2.910 | + 2.737 | + 4.050 | ||
SACCI-CISDd | RHF | D95 | 10.41 | 3.796 | 1.642 | 3.967 | 3.263 | + 9.869 | −3.502 | ||
TD-DFTe | PBE1 PBE | 6-31G(d) | 8.984 | 3.107 | 0.216 | 2.468 | 3.594 | −1.850 | + 19.55 | ||
TD-DFTe | B3LYP | 6-31G(d) | 9.041 | 2.941 | 0.294 | 2.398 | 3.447 | −3.902 | + 14.60 | ||
TD-DFTe | SVWN | 6-31G(d) | 9.364 | 1.933 | 0.004 | 2.087 | 2.197 | + 33.10 | + 46.68 | ||
expt f | ~ 2.4 | <0.2 | 2.737 | 2.218 |
Full single and double CI for an orbital basis set of the eight highest energy occupied and eight lowest energy unoccupied π orbitals plus single CI involving the three highest energy occupied σ and single lowest energy unoccupied σ orbitals (CISD 8π × 8π + CIS 3 × 1 = 99 singles + 2048 doubles).
As in footnote a but with CISD 9π × 9π + CIS 3 × 1 = 120 singles + 3080 doubles.
As in footnote a but with partial inclusion of quadruples via coupled-cluster perturbation.
SACCI-CISD based on the 52 highest energy occupied and 52 lowest energy unoccupied orbitals with full single and partial double CI (2704 singles + 15939 doubles).
Excited state dipole moments are calculated by using the one-particle CI density.
Transition energies (ΔE ≈ 8062 cm−1) and oscillator strengths (fosc) based on fucoxanthin in THF assuming molar absorptivity of 109400 L/mol/cm.75 The transition energy of the -like state is estimated on the basis of fluorescence studies.