Cobalt Complexes Supported by cis-Macrocyclic Diphosphines: Synthesis, Reactivity, and Activity toward Coupling Carbon Dioxide and Ethylene
The coordination chemistry of cis-macrocyclic diphosphines readily accessed from white phosphorus was explored, with a focus on preparing and studying cobalt complexes. cis-1,6-Dicyclohexyl-3,4,8,9-tetramethyl-2,5,7,10-tetrahydro-1,6-DiPhospheCine, or Cy2–DPC (1), was primarily used as a model dipho...
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Published in | Organometallics Vol. 36; no. 24; pp. 4834 - 4843 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
WASHINGTON
American Chemical Society
26.12.2017
Amer Chemical Soc |
Subjects | |
Online Access | Get full text |
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Summary: | The coordination chemistry of cis-macrocyclic diphosphines readily accessed from white phosphorus was explored, with a focus on preparing and studying cobalt complexes. cis-1,6-Dicyclohexyl-3,4,8,9-tetramethyl-2,5,7,10-tetrahydro-1,6-DiPhospheCine, or Cy2–DPC (1), was primarily used as a model diphosphine. Cobalt(II) dihalide diphosphine complexes such as (Cy2–DPC)CoX2, X = Cl (2) and I (3), were prepared, and their reactivity toward a variety of reducing agents was studied. We were successful in preparing and structurally characterizing an unusual iodide-bridged cobalt(I) dimer, [(Cy2–DPC)CoI]2 (8). These cobalt complexes were also investigated as potential catalysts for the coupling of carbon dioxide and ethylene to produce acrylate, a valuable polymer precursor. Although not yet catalytic, the first examples of cobalt complexes capable of mediating this transformation are reported. Notably, the well-known commercial complex ClCo(PPh3)3 was also found to be active in mediating acrylate production. As part of our mechanistic investigation, a pseudotetrahedral cobalt methyl acrylate complex, (Cy2–DPC)CoI(CH2CHCOOMe) (10), was prepared and structurally characterized. |
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ISSN: | 0276-7333 1520-6041 |
DOI: | 10.1021/acs.organomet.7b00734 |