Table 3.
Bulk electrolysis experiments for H2 evolution from various acids (50 mmol) catalyzed by Co and Ni complexes (0.5 mmol) carried out in CH3CN (nBu4NBF4 0.1 mol·L−1) at a graphite rod electrode
| Catalyst | Proton source | Applied potential, V vs. Fc+/0 | TON/3 h | Faradaic yield, % |
|---|---|---|---|---|
| [Co(DO)(DOH)pnBr2] | p-CN(C6H4)NH3(BF4) | −0.78 | 40 | 92 |
| Tosic acid | −0.83 | 4 | 50 | |
| PhNH3(BF4) | −0.97 | 27 | 90 | |
| TFA | −1.0 | 20 | 91 | |
| [Co((DO)2BF2)pnBr2] | p-CN(C6H4)NH3(BF4) | −0.82 | 20 | 100 |
| Tosic acid | −0.85 | 15 | 100 | |
| TFA | −0.89 | 7 | 90 | |
| [Ni(DO)(DOH)pn](ClO4) | Et3NHCl | −1.54 | 7 | 30 |
| [Ni((DO)2BF2)pn](ClO4) | p-CN(C6H4)NH3(BF4) | −0.95 | 4 | 60 |
| [Ni(MO)(MOH)pnCl] | p-CN(C6H4)NH3(BF4) | −1.1 | 20 | 70 |
| [Co(dmgBF2)2(CH3CN)2] | p-CN(C6H4)NH3(BF4) | −0.92 | 50 | ≈100 |
| [Co(dmgH)2pyCl] | Et3NHCl | −1.32 | 50 | >85 |
The amount of evolved hydrogen has been determined through GC analysis.