Abstract
The interactions between pendant amines in the second coordination sphere and ligands in the first coordination sphere are important for understanding the structures and reactivity of complexes containing P R 2 N R′ 2 ligands, which have been shown to be highly active H 2 oxidation/production catalysts. A series of [Fe(P Ph 2 N Bn 2 ) 2 (X)(Y)] n+ complexes have been prepared and structurally characterized. These complexes have two different ligands with which the pendant amines of the diphosphine ligand can interact. The solid state structure of cis-Fe(P Ph 2 N Bn 2 ) 2 Cl 2 reveals that the six-membered rings adjacent to the P atoms are in a boat confirmation, resulting in close N⋯P distances that suggests the P atoms have a greater affinity for the lone pair of electrons on the N atom than chloride ligands. Similarly, boat conformations are observed for both rings adjacent to the hydride ligands of trans-[HFe(P Ph 2 N Bn 2 ) 2 (CH 3 CN)] + and trans-HFe(P Ph 2 N Bn 2 ) 2 Cl, resulting in short N⋯H distances. Spectroscopic and computational studies of trans-[HFe(P Ph 2 N Bn 2 ) 2 (CO)] + , trans-[HFe(P Ph 2 N Bn 2 )(P Ph 2 N Bn 2 H)(CO)] 2+ , and trans-[HFe(P Ph 2 N Bn 2 ) 2 (H 2 )] + indicate the complexes are more stable when the pendant amines in boat conformations are adjacent to the hydride ligand. These data suggest an attractor ordering of H - > CO > H 2 > PR 3 > Cl - ∼ CH 3 CN.
| Original language | English |
|---|---|
| Pages (from-to) | 4867-4878 |
| Number of pages | 12 |
| Journal | Dalton Transactions |
| Volume | 48 |
| Issue number | 15 |
| DOIs | |
| Publication status | Published - Jan 1 2019 |
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ASJC Scopus subject areas
- Inorganic Chemistry
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Evaluation of attractive interactions in the second coordination sphere of iron complexes containing pendant amines. / Liao, Qian; Liu, Tianbiao; Johnson, Samantha I.; Klug, Christina M.; Wiedner, Eric; Bullock, R Morris; DuBois, Daniel L.
In: Dalton Transactions, Vol. 48, No. 15, 01.01.2019, p. 4867-4878.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Evaluation of attractive interactions in the second coordination sphere of iron complexes containing pendant amines
AU - Liao, Qian
AU - Liu, Tianbiao
AU - Johnson, Samantha I.
AU - Klug, Christina M.
AU - Wiedner, Eric
AU - Bullock, R Morris
AU - DuBois, Daniel L
PY - 2019/1/1
Y1 - 2019/1/1
N2 - The interactions between pendant amines in the second coordination sphere and ligands in the first coordination sphere are important for understanding the structures and reactivity of complexes containing P R 2 N R′ 2 ligands, which have been shown to be highly active H 2 oxidation/production catalysts. A series of [Fe(P Ph 2 N Bn 2 ) 2 (X)(Y)] n+ complexes have been prepared and structurally characterized. These complexes have two different ligands with which the pendant amines of the diphosphine ligand can interact. The solid state structure of cis-Fe(P Ph 2 N Bn 2 ) 2 Cl 2 reveals that the six-membered rings adjacent to the P atoms are in a boat confirmation, resulting in close N⋯P distances that suggests the P atoms have a greater affinity for the lone pair of electrons on the N atom than chloride ligands. Similarly, boat conformations are observed for both rings adjacent to the hydride ligands of trans-[HFe(P Ph 2 N Bn 2 ) 2 (CH 3 CN)] + and trans-HFe(P Ph 2 N Bn 2 ) 2 Cl, resulting in short N⋯H distances. Spectroscopic and computational studies of trans-[HFe(P Ph 2 N Bn 2 ) 2 (CO)] + , trans-[HFe(P Ph 2 N Bn 2 )(P Ph 2 N Bn 2 H)(CO)] 2+ , and trans-[HFe(P Ph 2 N Bn 2 ) 2 (H 2 )] + indicate the complexes are more stable when the pendant amines in boat conformations are adjacent to the hydride ligand. These data suggest an attractor ordering of H - > CO > H 2 > PR 3 > Cl - ∼ CH 3 CN.
AB - The interactions between pendant amines in the second coordination sphere and ligands in the first coordination sphere are important for understanding the structures and reactivity of complexes containing P R 2 N R′ 2 ligands, which have been shown to be highly active H 2 oxidation/production catalysts. A series of [Fe(P Ph 2 N Bn 2 ) 2 (X)(Y)] n+ complexes have been prepared and structurally characterized. These complexes have two different ligands with which the pendant amines of the diphosphine ligand can interact. The solid state structure of cis-Fe(P Ph 2 N Bn 2 ) 2 Cl 2 reveals that the six-membered rings adjacent to the P atoms are in a boat confirmation, resulting in close N⋯P distances that suggests the P atoms have a greater affinity for the lone pair of electrons on the N atom than chloride ligands. Similarly, boat conformations are observed for both rings adjacent to the hydride ligands of trans-[HFe(P Ph 2 N Bn 2 ) 2 (CH 3 CN)] + and trans-HFe(P Ph 2 N Bn 2 ) 2 Cl, resulting in short N⋯H distances. Spectroscopic and computational studies of trans-[HFe(P Ph 2 N Bn 2 ) 2 (CO)] + , trans-[HFe(P Ph 2 N Bn 2 )(P Ph 2 N Bn 2 H)(CO)] 2+ , and trans-[HFe(P Ph 2 N Bn 2 ) 2 (H 2 )] + indicate the complexes are more stable when the pendant amines in boat conformations are adjacent to the hydride ligand. These data suggest an attractor ordering of H - > CO > H 2 > PR 3 > Cl - ∼ CH 3 CN.
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U2 - 10.1039/c9dt00708c
DO - 10.1039/c9dt00708c
M3 - Article
VL - 48
SP - 4867
EP - 4878
JO - Dalton Transactions
JF - Dalton Transactions
SN - 1477-9226
IS - 15
ER -