Energy of intrashell d–d transitions (in MeOH solution for E(4T2) and in the solid state for E(2T1) and E(2E)), ligand-field strength Δ (eqn (1)) and Racah parameters B (eqn (2)) and C (eqn (3)) for [Cr(H2biim)3](NO3)3, [Cr(Hbiim)2(biim)]PPh4, [Cr(Me2biim)3](CF3SO3)3, and [Cr(phen)2(H2biim)]3+ and for closely related pseudo-octahedral [CrIIIN6] chromophoresa.
| Complex | E(4T2)/cm−1 | E(2T1)/cm−1 | E(2E)/cm−1 | Δ/cm−1 | B/cm−1 | C/cm−1 | E(4T2) − E(2E)/cm−1 | Δ/B | C/B | Ref. |
|---|---|---|---|---|---|---|---|---|---|---|
| [Cr(H2biim)3]3+ | 20 268 | 14 376 | 13 717 | 20 268 | 717 | 2845 | 6551 | 28.3 | 4.0 | This work |
| [Cr(Hbiim)3] | — | 14 263 | 13 670 | — | — | — | — | — | — | This work |
| [Cr(Hbiim)2(biim)]− | 19 956 | 14 096 | 13 482 | 19 956 | 686 | 2828 | 6474 | 29.1 | 4.1 | This work |
| [Cr(Me2biim)3]3+ | 21 026 | 14 164 | 13 538 | 21 026 | 712 | 2779 | 7488 | 29.6 | 3.9 | This work |
| [Cr(phen)2(H2biim)]3+ | 23 202 | 14 381 | 13 723 | 23 202 | 766 | 2697 | 9479 | 30.3 | 3.5 | This work |
| [Cr(bpy)3]3+ | 23 400 | 14 450 | 13 800 | 23 400 | 765 | 2730 | 9600 | 30.6 | 3.6 | 60 |
| [Cr(phen)3]3+ | 22 075 | 14 451 | 13 736 | 22 075 | 779 | 2700 | 8339 | 28.3 | 3.5 | 53 |
| [Cr(tpy)2]3+ | 18 750 | 13 584 | 12 953 | 18 750 | 790 | 2512 | 5797 | 23.7 | 3.2 | 61 |
| [Cr(ddpd)2]3+ | 22 990 | 13 550 | 12 903 | 22 990 | 756 | 2419 | 10 087 | 30.4 | 3.2 | 23 |
| [Cr(dqp)2]3+ | 24 937 | 13 864 | 13 405 | 24 937 | 656 | 2791 | 11 532 | 38.0 | 4.3 | 24 |
| [Cr(dpc)2]+ | 19 200 | — | 9370 | 19 200 | 470 | 1880 | 9830 | 40.9 | 4.0 | 62 |
| [Cr(CN)6]3− | 26 600 | — | 12 400 | 26 600 | 480 | 2800 | 14 200 | 55.4 | 5.8 | 63 |
| [Cr(bik)3]3+ | 23 094 | 14 771 | 14 044 | 23 094 | 804 | 2737 | 9050 | 28.7 | 3.4 | 57 |
| [Cr(bim)3]3+ | 21 008 | 14 859 | 14 104 | 21 008 | 781 | 2842 | 6904 | 26.9 | 3.6 | 57 |
| [Cr(bie)3]3+ | 20 747 | 14 837 | 14 124 | 20 747 | 754 | 2902 | 6623 | 27.5 | 3.8 | 57 |