Abstract
A series of iron hydride complexes featuring PRN R′OPR (PRNR′ PR = R2PCH2N(R′)CH2PR 2 where R = Ph, R′ = Me; R = Et, R′ = Ph, Bn, Me, tBu) and cyclopentadienide (CpX = C5H 4X where X = H, C5F4N) ligands has been synthesized; characterized by NMR spectroscopy, X-ray diffraction, and cyclic voltammetry; and examined by quantum chemistry calculations. Each compound was tested for the electrocatalytic oxidation of H2, and the most active complex, (CpC5F4N)Fe(PEtNMeP Et)(H), exhibited a turnover frequency of 8.6 s-1 at 1 atm of H2 with an overpotential of 0.41 V, as measured at the potential at half of the catalytic current and using N-methylpyrrolidine as the exogenous base to remove protons. Control complexes that do not contain pendant amine groups were also prepared and characterized, but no catalysis was observed. The rate-limiting steps during catalysis are identified through combined experimental and computational studies as the intramolecular deprotonation of the FeIII hydride by the pendant amine and the subsequent deprotonation by an exogenous base.
| Original language | English |
|---|---|
| Pages (from-to) | 1246-1260 |
| Number of pages | 15 |
| Journal | ACS Catalysis |
| Volume | 4 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Apr 4 2014 |
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Keywords
- diphosphine
- electrocatalyst
- hydrogen oxidation
- iron
- piano-stool
- proton relay
ASJC Scopus subject areas
- Catalysis
Cite this
Iron complexes for the electrocatalytic oxidation of hydrogen : Tuning primary and secondary coordination spheres. / Darmon, Jonathan M.; Raugei, Simone; Liu, Tianbiao; Hulley, Elliott B.; Weiss, Charles J.; Bullock, R Morris; Helm, Monte.
In: ACS Catalysis, Vol. 4, No. 4, 04.04.2014, p. 1246-1260.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Iron complexes for the electrocatalytic oxidation of hydrogen
T2 - Tuning primary and secondary coordination spheres
AU - Darmon, Jonathan M.
AU - Raugei, Simone
AU - Liu, Tianbiao
AU - Hulley, Elliott B.
AU - Weiss, Charles J.
AU - Bullock, R Morris
AU - Helm, Monte
PY - 2014/4/4
Y1 - 2014/4/4
N2 - A series of iron hydride complexes featuring PRN R′OPR (PRNR′ PR = R2PCH2N(R′)CH2PR 2 where R = Ph, R′ = Me; R = Et, R′ = Ph, Bn, Me, tBu) and cyclopentadienide (CpX = C5H 4X where X = H, C5F4N) ligands has been synthesized; characterized by NMR spectroscopy, X-ray diffraction, and cyclic voltammetry; and examined by quantum chemistry calculations. Each compound was tested for the electrocatalytic oxidation of H2, and the most active complex, (CpC5F4N)Fe(PEtNMeP Et)(H), exhibited a turnover frequency of 8.6 s-1 at 1 atm of H2 with an overpotential of 0.41 V, as measured at the potential at half of the catalytic current and using N-methylpyrrolidine as the exogenous base to remove protons. Control complexes that do not contain pendant amine groups were also prepared and characterized, but no catalysis was observed. The rate-limiting steps during catalysis are identified through combined experimental and computational studies as the intramolecular deprotonation of the FeIII hydride by the pendant amine and the subsequent deprotonation by an exogenous base.
AB - A series of iron hydride complexes featuring PRN R′OPR (PRNR′ PR = R2PCH2N(R′)CH2PR 2 where R = Ph, R′ = Me; R = Et, R′ = Ph, Bn, Me, tBu) and cyclopentadienide (CpX = C5H 4X where X = H, C5F4N) ligands has been synthesized; characterized by NMR spectroscopy, X-ray diffraction, and cyclic voltammetry; and examined by quantum chemistry calculations. Each compound was tested for the electrocatalytic oxidation of H2, and the most active complex, (CpC5F4N)Fe(PEtNMeP Et)(H), exhibited a turnover frequency of 8.6 s-1 at 1 atm of H2 with an overpotential of 0.41 V, as measured at the potential at half of the catalytic current and using N-methylpyrrolidine as the exogenous base to remove protons. Control complexes that do not contain pendant amine groups were also prepared and characterized, but no catalysis was observed. The rate-limiting steps during catalysis are identified through combined experimental and computational studies as the intramolecular deprotonation of the FeIII hydride by the pendant amine and the subsequent deprotonation by an exogenous base.
KW - diphosphine
KW - electrocatalyst
KW - hydrogen oxidation
KW - iron
KW - piano-stool
KW - proton relay
UR - http://www.scopus.com/inward/record.url?scp=84898069268&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84898069268&partnerID=8YFLogxK
U2 - 10.1021/cs500290w
DO - 10.1021/cs500290w
M3 - Article
AN - SCOPUS:84898069268
VL - 4
SP - 1246
EP - 1260
JO - ACS Catalysis
JF - ACS Catalysis
SN - 2155-5435
IS - 4
ER -