Stereochemistry and exchange processes in five-coordinate cobalt(I) complexes containing one of three triphosphine ligands

Daniel L DuBois, Devon W. Meek

Research output: Contribution to journalArticle

51 Citations (Scopus)


Six extensive series of five-coordinate complexes of the types [Co(triphos)(CO)2]X and [Co(triphos)L(CO)]X (X = BF4, PF6; L = P(OMe)3, PPh2H, PPh2Me, PEt3, PPh3; triphos = either bis(3-diphenylphosphinopropyl)phenylphosphine (ttp), bis(2-diphenylphosphinoethyl)phenylphosphine (etp), or 1,1,1-tris(diphenylphosphinomethyl)ethane (tripod-P3)) were synthesized and their stereochemistry and dynamic behavior studied principally by 31P{1H} NMR. The details of the stereochemistry and exchange processes depend both on the monodentate ligand and on the triphosphine ligand. For example, the [Co(etp)L(CO)]X and [Co(etp)(CO)2]X complexes are trigonal bipyramidal with the equatorial positions occupied by a carbonyl ligand and the two terminal phosphorus atoms of the triphosphine ligand; the axial positions are occupied by the central phosphorus atom and either a monophosphine or a carbonyl ligand, respectively. The [Co(ttp)L(CO)]X complexes have square-pyramidal structures with L located at the axial position. A trigonal-bipyramidal structure is assigned to the dicarbonyl complexes [Co(ttp)(CO)2]X. The complexes [Co(tripod-P3)L(CO)]X are stereochemically nonrigid, whereas those of [Co(etp)L(CO)]X are stereochemically rigid at room temperature. A large number of 2JPP coupling constants are presented for these complexes.

Original languageEnglish
Pages (from-to)3076-3083
Number of pages8
JournalInorganic Chemistry
Issue number12
Publication statusPublished - 1976


ASJC Scopus subject areas

  • Inorganic Chemistry

Cite this