Synthesis, characterization and reactions of [RhCl(CO){(Ph2P(CH2CH2O)mCH2CH2Ph2-P,P’)}]n (m = 3, 4, 5 n = 1, 2 …) metallacrown crown ethers

Academic Article

Abstract

  • The reactions of [RhCl(cod)]2 and Ph2P(CH2CH2O)nCH2CH2PPh2P (n = 3, 4, 5) under a CO atmosphere yield [RhCl(CO){(Ph2P(CH2CH2O)n CH2CH2Ph2-P,P′)}]m monocarbonyl metallacrown ethers. These complexes are mixtures of cyclic n-mers and monomers with trans coordination geometries at the rhodium. The monocarbonyl rhodium metallacrown ethers reversibly react with CO at atmospheric pressure to form [RhCl(CO)2{(Ph2P(CH2CH2O)nCH2CH2Ph2-P,P′)}]m dicarbonyl metallacrown ethers. These complexes are only stable under a CO atmosphere as demonstrated by 31P{1H} NMR spectroscopy. Upon prolonged exposure to the atmosphere, all the monocarbonyl metallacrown ethers lose CO and undergo phosphine ligand oxidation to form [RhCl(H2O){Ph2P(O)(CH2CH2O)nCH2CH2P(O)Ph2-O,O’}] metallacrown ethers. These are the first examples of metallacrown ethers in which the transition metal is coordinated via phosphine oxide donors.
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    Author List

  • Smith DC; Cagle EC; Gray GM
  • Start Page

  • 78
  • End Page

  • 82
  • Volume

  • 876