Porylledron Vol. 9, No. IO. pp. 124!W256,1990 Printed in Great Britain 0277-5387/!Xl $3.00+ .oO 8 1990 Pergamon Plw plc zyxwvuts “0, 31P AND’=W NMR SPECTRA OF P ARAMAGNETIC COMPLEXES WITH THE HETEROPOLYTUNGSTATE ANION [Ln(PWllO&“- AND THEIR CONSTITUTION IN AQUEOUS SOLUTION. Ln-RARE EARTH ELENA MARTIN A. FEDOTOV* Institute of Catalysis, 630090 Novosibirsk, U.S.S.R. and BORIS zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGF Z. PERTSIKOV Irkutsk Polytekhnik Institute, Irkutsk, U.S.S.R. zyxwvutsrqponmlkjihgfedcbaZYXW and DAVID K. DANOVICH Irkutsk Institute of Organic Chemistry, Irkutsk, U.S.S.R. (Received 18 September 1989 ; accepted 8 December 1989) Abstract-Lanthanide complexes from La to Yb with IpW, ,039]7- ligands were studied by “0, 3’P and “‘W NMR methods. The complexes are non-labile on the NMR time scale, and their 1: 2 composition in solution was confirmed by 3’P NMR. Contact and dipolar cont~b~tions to the lanthanide induced shift (LIS) of ligand nuclei have been estimated. The geometry of the ligand was shown to change in the lanthanide series and the dipolar contribution to LIS increases compared to the contact contribution, as the distance from the lanthanide ion increases. Lanthanide(II1) complexes, known as lanthanide shift reagents (LSR), are tools for the simplification and inte~re~tion of NMR spectra and the strnc- tural analysis of organic molecules in solution. ’ On the other hand, “0 and “‘W NMR can give some information about the structure of poly- tungstates in solution. 2-4Comparison of X-ray and “0 NMR data shows a change of bond length in heteropolyanions (HPA) of tungsten and molyb- denum on dissolution. Equivalent bonds of NPA become more equal in solution than in the crystal. ‘e4 “0 and ‘83W NMR studies of the lanthanide com- plexes of pW1 1039]7”-HPA (PW, J were expected to give additional information about the structure and NMR spectra of HPA. The inorganic tetradentate macroligand zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFED PW, , is known’ to form Ln(PW,,), complexes with lan- *Author to whom correspondence should he addressed. thanide ions, which are HPA with two heteroatom types. We are not aware of structural or NMR “0 studies which can give structural info~ation3 on these HPA. In the present paper “0, 3’P and ‘83W NMR spectra of Ln(PW 1 &HPA and their con- stitution in aqueous solution were studied for all stable lanthanides. EXPERIMENTAL The Ln(PW, Jt complexes were prepared with solid chloride or nitrate lanthanide salts added to a 0.3 M aqueous solution of the sodium salt of PW, iHPA in the ratio Ln: PW,, = 1: 2. The natural abundance of 3‘P I70 and ls3W NMR spectra was recorded with a Bruker CXP300 spec- trometer at 121.47, 40.7 and 12.5 MHz, respec- tively. Chemical shifts (CS) in 6 scale are given to external references Hz0 (170), 85% H3P04 (3’P) zyxwvu 1249