[sup 1]H NMR spectroscopic study of paramagnetic lanthanide(III) texaphyrins. Effect of axial ligation

Journal Article · Wed Mar 01 00:00:00 EST 1995 · Journal of the American Chemical Society; (United States)

DOI:https://doi.org/10.1021/ja00113a016· OSTI ID:6455625

Lisowski, J; Sessler, J L; Lynch, V; Mody, T D ^[1]

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1. Univ. of Texas, Austin, TX (United States)

Paramagnetic Ce(III), Pr(m), Nd(III), Sm(III), Eu(III), Tb(III), Dy(III), Ho(III), Er(III), Tm(III), and Yb(III) texaphyrins were studied in solution using [sup 1]H NMR spectroscopic techniques. Key spectroscopic features for the dinitrate complexes LnTx(NO[sub 3])[sub 2] were assigned on the basis of 1D NOE, COSY, and ROESY experiments as well as line width and isotropic shift analysis. The observed isotropic shifts can be fit to theoretical models, assuming dipolar contributions are dominant for all but the imino protons. The resulting calculated values are consistent with highly rhombic magnetic susceptibility tensors for those paramagnetic lanthanide texaphyrins in which one of the molecular magnetic axes is roughly perpendicular to the macrocycle plane. For the dinitrate complexes, a change in the magnetic anisotropy was observed between the Ho(ITI) and Er(III) texaphyrin complexes, a phenomenon that is considered reflective of the changes in metal-centered axial ligation that occur as the lanthanide series is transversed. Conformation of phosphate coordination in the solid state came from a single crystal X-ray diffraction analysis of the bis(diphenyl phosphate) adduct of Dy(III) texaphyrin. The Dy(III) ion is seven-coordinate with five donor atoms being provided by the texaphyrin ligand and two by monodentate diphenyl phosphate ions. The Dy(III) ion is only 0.073 A from the plane through the five nitrogen atoms of the macrocycle. 35 refs., 7 figs., 5 tabs.

• OSTI ID: 6455625
• Journal Information: Journal of the American Chemical Society; (United States), Vol. 117:8; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
PORPHYRINS
NMR SPECTRA
RARE EARTH COMPLEXES
BOND LENGTHS
CHEMICAL SHIFT
CRYSTAL STRUCTURE
MOLECULAR STRUCTURE
NUMERICAL DATA
PARAMAGNETISM
CARBOXYLIC ACIDS
COMPLEXES
DATA
DIMENSIONS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INFORMATION
LENGTH
MAGNETISM
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
SPECTRA
400201* - Chemical & Physicochemical Properties
400102 - Chemical & Spectral Procedures
400702 - Radiochemistry & Nuclear Chemistry- Properties of Radioactive Materials