Structures in solution and in the solid state of the complexes of lanthanum(III) with 1,10-phenanthroline. X-ray crystallographic and [sup 1]H, [sup 13]C, [sup 17]O, and [sup 139]La solution NMR studies

Journal Article · Wed Apr 29 04:00:00 EDT 1992 · Inorganic Chemistry; (United States)

DOI:https://doi.org/10.1021/ic00035a025· OSTI ID:7017535

Frechette, M; Butler, I R; Detellier, C ^[1]; Hynes, R ^[2]

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1. Univ. of Ottawa Campus, Ontario (Canada)
2. National Research Council, Ottawa, Ontario (Canada)

The reaction between hexahydrated lanthanum(III) nitrate and 1,10-phenanthroline (phen) in acetonitrile solution was investigated by [sup 1]H, [sup 13]C, [sup 17]O, and [sup 139]La NMR spectroscopy. The crystal structure of trinitratobis(1,10-phenanthroline)lanthanum(III) (La-(NO[sub 3])[sub 3](C[sub 12]H[sub 8]N[sub 2])[sub 2]) was determined by X-ray diffraction as having a monoclinic lattice. In solution, [sup 139]La NMR spectra have shown up to three sites in slow exchange with variable intensities. They were attributed to solvated La(III) ions and to two complex species with one or two phen ligands in the La(III) coordination shell. A more complete structural analysis by [sup 17]O NMR spectroscopy indicated that during the course of the complexation by phen, coordinated water was totally expelled from the La(III) coordination sphere, whereas all three nitrate groups remained coordinated. Proton NMR data have confirmed the total displacement of water. In addition, the proton chemical shifts of phen, in comparison with the [sup 13]C NMR data, clearly showed an anisotropic shielding contribution when two phen ligands were coordinated to La(III). This indicates that the two phen molecules are in a close vicinity in the coordination sphere. From the NMR results, one can conclude that the structure in solution of the 2:1 complex, La(NO[sub 3])[sub 3](phen)[sub 2], is very similar to the solid-state one. From [sup 139]La NMR spectroscopy, the populations of the various La(III) species were obtained and the apparent formation constants were calculated.

• OSTI ID: 7017535
• Journal Information: Inorganic Chemistry; (United States), Journal Name: Inorganic Chemistry; (United States) Vol. 31:9; ISSN 0020-1669; ISSN INOCAJ
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102* -- Chemical & Spectral Procedures
400201 -- Chemical & Physicochemical Properties
AROMATICS
AZAARENES
BOND ANGLE
BOND LENGTHS
CHEMICAL REACTIONS
CHEMICAL SHIFT
COHERENT SCATTERING
COMPLEXES
CRYSTAL STRUCTURE
DIFFRACTION
DIMENSIONS
HETEROCYCLIC COMPOUNDS
LANTHANUM COMPLEXES
LANTHANUM COMPOUNDS
LANTHANUM NITRATES
LENGTH
LIGANDS
MOLECULAR STRUCTURE
NITRATES
NITROGEN COMPOUNDS
NMR SPECTRA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
PHENANTHROLINES
RARE EARTH COMPLEXES
RARE EARTH COMPOUNDS
SCATTERING
SPECTRA
STRUCTURAL CHEMICAL ANALYSIS
X-RAY DIFFRACTION