ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis and properties of lanthanide(III) complexes with 4-hydroxy-3,5-dimethoxybenzoic acid

M. Iwan, A. Kula, Z. Rzączyńska, S. Pikus, D. Flisiuk, and M. Gomoła

Department of General and Coordination Chemistry, Faculty of Chemistry, Maria Curie Sklodowska University, Maria Curie Sklodowska Sq. 2, 20-031 Lublin, Poland

E-mail: mariolas@hermes.umcs.lublin.pl

Received: 11 December 2006  Revised: 11 April 2007  Accepted: 16 April 2007

Abstract: Complexes of yttrium(III) and lanthanides(III) with 4-hydroxy-3,5-dimethoxybenzoic (syringic) acid were obtained as solids with metal to ligand mole ratio of 1: 3. The compounds were characterized by elemental analysis, IR spectroscopy, X-ray diffraction patterns, solubility, and thermal studies. The complexes are sparingly soluble in water and stable at room temperature. Compounds of light lanthanides (from La to Nd) are hydrated and they crystallize in a triclinic system. When heated, they lose water molecules in one step and in the next step they decompose to oxides. Complexes of yttrium and other lanthanides are anhydrous and crystallize in a monoclinic system. They are stable up to 300°C and then decompose to oxides. As the coordination number of lanthanide ions is usually equal to 9 or 8, one can suppose that hydroxy or methoxy groups take part in the coordination of these metal ions.

Keywords: syringic acid - 4-hydroxy-3,5-dimethoxybenzoic acid - phenolic acid - lanthanide complexes

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-007-0051-2

Chemical Papers 61 (5) 376–382 (2007)