Abstract
Two new Ni(II) complexes, the homoleptic [Ni(8PCy 2NH)2]2+ complex (8PCy 2NH = 3,7-cyclohexyl-1-amino-3,7-diphosphacyclooctane) containing two pendant amines on adjacent ligands, and the heteroleptic [Ni(8PCy 2NH)(dppe)]2+ complex (dppe = bis(diphenylphosphino)ethane) containing only a single pendant amine, have been synthesized, and their electrochemical properties are reported. The [Ni(8PCy 2NH)(dppe)]2+ complex is capable of heterolytically cleaving hydrogen, allowing for the first observation of an endo-protonated nickel hydride related to the [Ni(PR 2NR′ 2)2]2+ family of complexes. The [Ni(8PCy 2NH)(dppe)]2+ complex did not exhibit electrocatalytic H2 oxidation activity; however, [Ni(8PCy 2NH)2]2+ is an active electrocatalyst for H2 oxidation with a maximum turnover frequency (kobs) of 18 s-1 under 1 atm H2 at Ecat/2 = -0.71 V versus the ferrocenium/ferrocene (Cp2Fe+/0) couple. In addition to an analysis of the effect of the number of pendant amines on the rates of electrocatalytic H2 oxidation of compounds related to the [Ni(PR 2NR′ 2)2]2+ family, the effect of the secondary pendant amine on intermolecular deprotonation is discussed.
| Original language | English |
|---|---|
| Pages (from-to) | 2965-2974 |
| Number of pages | 10 |
| Journal | Organometallics |
| Volume | 35 |
| Issue number | 17 |
| DOIs | |
| Publication status | Published - Sep 12 2016 |
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ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry
Cite this
Nickel Bis-Diphosphine Complexes : Controlling the Binding and Heterolysis of H2. / Stolley, Ryan M.; Darmon, Jonathan M.; Das, Parthapratim; Helm, Monte.
In: Organometallics, Vol. 35, No. 17, 12.09.2016, p. 2965-2974.Research output: Contribution to journal › Review article
}
TY - JOUR
T1 - Nickel Bis-Diphosphine Complexes
T2 - Controlling the Binding and Heterolysis of H2
AU - Stolley, Ryan M.
AU - Darmon, Jonathan M.
AU - Das, Parthapratim
AU - Helm, Monte
PY - 2016/9/12
Y1 - 2016/9/12
N2 - Two new Ni(II) complexes, the homoleptic [Ni(8PCy 2NH)2]2+ complex (8PCy 2NH = 3,7-cyclohexyl-1-amino-3,7-diphosphacyclooctane) containing two pendant amines on adjacent ligands, and the heteroleptic [Ni(8PCy 2NH)(dppe)]2+ complex (dppe = bis(diphenylphosphino)ethane) containing only a single pendant amine, have been synthesized, and their electrochemical properties are reported. The [Ni(8PCy 2NH)(dppe)]2+ complex is capable of heterolytically cleaving hydrogen, allowing for the first observation of an endo-protonated nickel hydride related to the [Ni(PR 2NR′ 2)2]2+ family of complexes. The [Ni(8PCy 2NH)(dppe)]2+ complex did not exhibit electrocatalytic H2 oxidation activity; however, [Ni(8PCy 2NH)2]2+ is an active electrocatalyst for H2 oxidation with a maximum turnover frequency (kobs) of 18 s-1 under 1 atm H2 at Ecat/2 = -0.71 V versus the ferrocenium/ferrocene (Cp2Fe+/0) couple. In addition to an analysis of the effect of the number of pendant amines on the rates of electrocatalytic H2 oxidation of compounds related to the [Ni(PR 2NR′ 2)2]2+ family, the effect of the secondary pendant amine on intermolecular deprotonation is discussed.
AB - Two new Ni(II) complexes, the homoleptic [Ni(8PCy 2NH)2]2+ complex (8PCy 2NH = 3,7-cyclohexyl-1-amino-3,7-diphosphacyclooctane) containing two pendant amines on adjacent ligands, and the heteroleptic [Ni(8PCy 2NH)(dppe)]2+ complex (dppe = bis(diphenylphosphino)ethane) containing only a single pendant amine, have been synthesized, and their electrochemical properties are reported. The [Ni(8PCy 2NH)(dppe)]2+ complex is capable of heterolytically cleaving hydrogen, allowing for the first observation of an endo-protonated nickel hydride related to the [Ni(PR 2NR′ 2)2]2+ family of complexes. The [Ni(8PCy 2NH)(dppe)]2+ complex did not exhibit electrocatalytic H2 oxidation activity; however, [Ni(8PCy 2NH)2]2+ is an active electrocatalyst for H2 oxidation with a maximum turnover frequency (kobs) of 18 s-1 under 1 atm H2 at Ecat/2 = -0.71 V versus the ferrocenium/ferrocene (Cp2Fe+/0) couple. In addition to an analysis of the effect of the number of pendant amines on the rates of electrocatalytic H2 oxidation of compounds related to the [Ni(PR 2NR′ 2)2]2+ family, the effect of the secondary pendant amine on intermolecular deprotonation is discussed.
UR - http://www.scopus.com/inward/record.url?scp=84986879748&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84986879748&partnerID=8YFLogxK
U2 - 10.1021/acs.organomet.6b00486
DO - 10.1021/acs.organomet.6b00486
M3 - Review article
AN - SCOPUS:84986879748
VL - 35
SP - 2965
EP - 2974
JO - Organometallics
JF - Organometallics
SN - 0276-7333
IS - 17
ER -