C-13 AND P-31 NMR-STUDY OF PARAMAGNETIC LANTHANIDE(III) TEXAPHYRINS

A C-13 NMR study of representative trivalent lanthanide texaphyrins Ln Tx(NO3)(2) (Ln = La, Ce, Pr, Nd, Eu, and Y) is presented. The carbon-1 3 resonances were assigned on the basis of 2D proton-carbon correlatio n spectroscopy. The metal-centered dipolar contributions to the observ ed isotropic shifts of paramagnetic complexes have been calculated on the basis of previously determined magnetic anisotropy parameters and X-ray crystal structures. The origin of carbon-13 contact shift contri bution is discussed. P-31 NMR results for the diphenyl phosphonate der ivatives of Ce(III), Pr(III), Nd(III), Eu(III), Tb(III), Dy(III), Ho(I II), Er(III), Tm(III), and Yb(III) texaphyrins are also presented.