Table 1. Cyclic Voltammetry of [Re(3,3′-DHBPY)(CO)3Cl] and Related DHBPY Complexes.
| complex | solvent | cathodic wave | Ep,c (V vs Fc/Fc+) |
|---|---|---|---|
| [Re(3,3′-DHBPY)(CO)3Cl] | THF | R1 | –1.01 |
| –1.40a | |||
| [Re(3,3′-DHBPY)(CO)3Cl] | R1* | –1.90a,b | |
| [Re(3,3′-DHBPY)(CO)3Cl]•– | R2 | –2.38 | |
| [Re(3,3′-DHBPY-H+)(CO)3Cl]− | R2′ | –2.38 | |
| –2.30a | |||
| [Re(3,3′-DHBPY-H+)(CO)3Cl]−c | R2* | –2.16 | |
| [Re(3,3′-DHBPY)(CO)3Cl] [Re(3,3′-DHBPY-H+)(CO)3Cl]− | PrCN | R1 | –0.84 |
| –1.22a | |||
| R2′ | –2.30 | ||
| –2.25a | |||
| [Re(3,3′-DHBPY)(CO)3(PrCN)]+ | PrCN | R1 | –0.93 |
| [Re(3,3′-DHBPY-H+)(CO)3(PrCN)] | R2′ | –2.07 | |
| [Re(4,4′-DHBPY)(CO)3Cl]d,e | DMF | R1 | –1.98 |
| [Re(4,4′-DHBPY-H+)(CO)3Cl]− | R2 | –2.18 | |
| [Re(4,4′-DHBPY-2H+)(CO)3]− | R3 | –2.45 |
a
Measured at 195 K.
b
No concomitant reductive deprotonation of the 3,3′-DHBPY ligand taking place. E1/2= −1.87 V.
c
Prepared by chemical deprotonation of [Re(3,3′-DHBPY)(CO)3Cl] with 1 equiv of NaHMDS.
d
Measured by Fujita and co-workers.46
e
No deprotonation of the parent complex in DMF was reported