title: Coordination chemistry of tripyridinedimethane.
abstract: The ligand tripyridinedimethane (tpdm), consisting of three pyridine residues linked at their ortho carbons by two CH(2) groups, is shown to be a sterically flexible ligand capable of binding in a meridional arrangement in trigonal bipyramidal (tpdm) Cu(II)Cl(2) but binding in a facial arrangement in tetrahedral (tpdm) Cu(I)Cl. Nucleophilic substitution of chloride by (t)BuO(-) and PhC[triple bond]C(-) is possible, and deprotonation of the acidic benzylic protons does not take place because the resulting carbanion cannot achieve coplanarity with the aryl rings. RhCl(3) forms, with tpdm in boiling methanol, a 1:1 kinetic mixture of fac- and mer-isomers RhCl(3)(tpdm). The former isomerizes slowly at RT (room temperature) in DMSO solution into the latter with Rh-N bond dissociation as the rate-determining step.
authors.affiliation: Department of Chemistry and Molecular Structure Center, Indiana University, Bloomington, Indiana 47405-7102, USA.
authors.forename: Andrei N
authors.initials: AN
authors.lastname: Vedernikov
authors.forename: John C
authors.initials: JC
authors.lastname: Huffman
authors.forename: Kenneth G
authors.initials: KG
authors.lastname: Caulton