Synthesis, NMR characterization, and cation binding of metallacrown ethers with asymmetric Bis(phosphinite) and bis(phosphite) ligands derived from 2-hy droxy-2′-(1,4,7-trisoxo-9-nonanol)-1,1′-biphenyl

Academic Article

Abstract

  • Chlorodiphenylphosphine and 2,2′-biphenylylenephosphorochloridite react with 2-hydroxy2′-(1,4,7-trisoxo-9-nonanol)-1,1′-biphenyl to yield the new α,ω-bis(phosphorus-donor)polyether ligands Ph PO(CH CH O) -2-C H -2′-OPPh and (2,2/-O C H )P(CH CH O) -2-C H -2′P(2,2′-O C H ). These ligands react with Mo(CO) (nbd) to form the monomeric cis-metallacrown ethers cis-Mo(CO) {Ph PO(CH CH O) -2-C H -2′-OPPh } and cis-Mo(CO) {(2,2′-O C H )P(CH CH O) -2-C H -2′- P(2,2′-O C H )}. The X-ray crystal structure of cis-Mo(CO) {(2,2′-O C H )P(CH CH O) -2-C H -2′- P(2,2′-O C H )} indicates that in the solid state three of the four metallacrown ether ring oxygens point away from the cavity in the cis-metallacrown ether ring. Both metallacrown ethers undergo cis-trans isomerization in the presence of catalytic amounts of HgCl but yield quite different products, cis-Mo(CO) {Ph PO(CH CH O) -2-C H -2′-OPPh }·HgCl and trans-Mo(CO) {(2,2′-O C H )P( CH CH O) -2-C H -2 ′-P(2,2′-O C H )}·HgCl , when reacted with a stoichiometric amount of HgCl . NMR titrations of the cis-metallacrown ethers with lithium salts demonstrate that the cis-metallacrown ethers form 2:1 complexes with Li . The unexpected 2:1 ratio has been confirmed by the isolation of [cis-Mo(CO) {Ph PO(CH CH O) -2-C H -2′-OPPh ] LiBPh . In dichloromethane-d solution, this complex very slowly isomerizes to form a mixture of [trans-Mo(CO) {Ph PO(CH CH O) -2-C H -2′-OPPh ]LiBPh and the free cis-metallacrown ether, indicating that the frvzns-metallacrown ether more strongly binds Li than does the cis-metallacrown ether. Neither 2:1 stoichiometries for Li complexes of cis-metallacrown ethers nor complex formation by froms-metallacrown ethers have previously been reported. 2 2 2 3 12 8 2 2 12 8 2 2 3 12 8 2 12 8 4 4 2 2 2 3 12 8 2 4 2 12 8 2 2 3 12 8 2 12 8 4 2 12 8 2 2 3 12 8 2 12 8 2 4 2 2 2 3 12 8 2 2 4 2 12 8 2 2 3 12 8 2 12 8 2 2 + 4 2 2 2 3 12 8 2 2 4 2 4 2 2 2 3 12 8 2 4 + +
  • Authors

    Published In

  • Organometallics  Journal
  • Digital Object Identifier (doi)

    Author List

  • Butler JM; Jablonsky MJ; Gray GM
  • Start Page

  • 1081
  • End Page

  • 1088
  • Volume

  • 22
  • Issue

  • 5