Skip to main content
OSTI.GOVU.S. Department of Energy Office of Scientific and Technical Information
U.S. Department of Energy
Office of Scientific and Technical Information
 

Crystal and solution structure of the palladium(II) bis(1,4,7-triazacyclononane) ion: Evidence for rapid fluxional behavior in a macrocyclic complex

Journal Article · · Inorg. Chem.; (United States)
DOI:https://doi.org/10.1021/ic00288a015· OSTI ID:5826258
; ;
An unusual example of fluxionality at the normally inert Pd(II) center is described. The preparation and x-ray crystal structure of the Pd(non)/sub 2//sup 2+/ ion (non = 1,4,7-triazacyclononane) are presented. Pd(non)/sub 2/(PF/sub 6/)/sub 2/ crystallizes in the space group P2/sub 1//c with cell dimensions of a = 7.150 (1) /angstrom/, b = 16.675 (6) /angstrom/, c = 9.542 (3) /angstrom/, and /beta/ = 97.37 (2)/degree/ (Z = 2). In the solid state the ion displays square-planar geometry, Pd-N = 2.057 /angstrom/, with the third (noncoordinated) nitrogen atom in a configuration remote (/approximately/3.5 /angstrom/) from the metal center and the rings in an anti conformation. However, in solution at ambient temperatures, /sup 13/C NMR shows only a single resonance, explicable only by a rapid ring hopping of the Pd(II) around the triaza macrocycle. This is considered to be the first example of such behavior for a Pd(II) amine complex. Temperature-dependence studies have permitted identification of syn and anti conformations in equilibrium (K/sub eq/ /approx/ 2). Rate data for the interconversion have been obtained, and a possible mechanism is proposed. The fluxional behavior of this ion explains the ready oxidation by air in aqueous medium to a very stable hexacoordinate Pd(III) ion. 41 refs., 6 figs., 3 tabs.
Research Organization:
Univ. of Victoria, British Columbia (Canada)
OSTI ID:
5826258
Journal Information:
Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 27:15; ISSN INOCA
Country of Publication:
United States
Language:
English

Similar Records

Synthesis of the hexaamine ligand 1,4,7-tris(3-aminopropyl)-1,4,7-triazacyclononane: Reactivity and x-ray crystal structures of the nickel(II) and cobalt(III) complexes
Journal Article · Wed Jul 27 00:00:00 EDT 1988 · Inorg. Chem.; (United States) · OSTI ID:5614425
Bis(1,4,7-triazacyclononane)palladium(III): characterization and reactions of an unusually stable monomeric palladium(III) ion
Journal Article · Wed Sep 07 00:00:00 EDT 1988 · Inorg. Chem.; (United States) · OSTI ID:5852994
Synthesis and X-ray and neutron structures of anti-[L[sub 2]Rh[sub 2](H)[sub 2]](PF[sub 6])[sub 2] (L = 1,4,7-trimethyl-1,4,7-triazacyclononane) and a related species containing a syn-[Rh[sub 2](H)[sub 2]([mu]-H)[sub 2]][sup 2+] core. Isolation of [L[sub 2]Fe[sub 2]([mu]-H)[sub 3]]BPh[sub 4]
Journal Article · Wed Sep 29 00:00:00 EDT 1993 · Inorganic Chemistry; (United States) · OSTI ID:5078746

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400202 -- Isotope Effects
Isotope Exchange
& Isotope Separation
ALKANES
CARBON 13
CARBON ISOTOPES
CHEMICAL PREPARATION
COMPLEXES
CYCLOALKANES
DATA
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
HYDROCARBONS
INFORMATION
ISOTOPES
LIGHT NUCLEI
NMR SPECTRA
NUCLEI
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANOMETALLIC COMPOUNDS
PALLADIUM COMPLEXES
SPECTRA
STABLE ISOTOPES
SYNTHESIS
TRANSITION ELEMENT COMPLEXES