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Abstract The production of olefins via on‐purpose dehydrogenation of alkanes allows for a more efficient, selective and lower cost alternative to processes such as steam cracking. Silica‐supported pincer‐iridium complexes of the form [(≡SiO−R4POCOP)Ir(CO)] (R4POCOP=κ3‐C6H3‐2,6‐(OPR2)2) are effective for acceptorless alkane dehydrogenation, and have been shown stable up to 300 °C. However, while solution‐phase analogues of such species have demonstrated high regioselectivity for terminal olefin production under transfer dehydrogenation conditions at or below 240 °C, in open systems at 300 °C, regioselectivity under acceptorless dehydrogenation conditions is consistently low. In this work, complexes [(≡SiO−tBu4POCOP)Ir(CO)] (1) and [(≡SiO−iPr4PCP)Ir(CO)] (2) were synthesized via immobilization of molecular precursors. These complexes were used for gas‐phase butane transfer dehydrogenation using increasingly sterically demanding olefins, resulting in observed selectivities of up to 77 %. The results indicate that the active site is conserved upon immobilization.
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2,6-Bis[bis(1,1-dimethylethyl)phosphinito-κP]phenyl-κC]-trans-chlorohydro(phenylphosphine)iridium(III)
The molecular structure of an iridium complex featuring a phenylphosphine ligand is described. The reaction of (POCOP)IrHCl (1, POCOP = 2,6-(tBu2PO)2C6H3–) with phenylphosphine gives (POCOP)IrHCl(PH2Ph) (2) under mild conditions. The structural features are consistent with a classic pseudo-octahedral iridium compound with three neutral phosphine donors. Compound 1 is unreactive at elevated temperatures and is unreactive toward excess phenylphosphine under the sampled conditions.
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- Award ID(s):
- 2101766
- PAR ID:
- 10337561
- Date Published:
- Journal Name:
- Molbank
- Volume:
- 2022
- Issue:
- 2
- ISSN:
- 1422-8599
- Page Range / eLocation ID:
- M1388
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3390/M1388
