Coordination modes of pyridine-carboxylic acid derivatives in samarium (III) complexes

• Published in: Polyhedron Vol. 25; no. 12; pp. 2471 - 2482
• Main Authors: Soares-Santos, Paula C.R., Paz, Filipe A. Almeida, Ferreira, Rute A. Sá, Klinowski, Jacek, Carlos, Luís D., Trindade, Tito, Nogueira, Helena I.S.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 21.08.2006
• Subjects: Coordination modes; Crystal structures; Lanthanide complexes; Luminescence; N, O ligands; Crystal structures; N, O ligands; Coordination modes; Lanthanide complexes; Luminescence
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2006.03.002

Coordination modes of picolinic, 3-hydroxypicolinic and 2-hydroxynicotinic acids in samarium (III) complexes were investigated, showing N, O- or O, O-chelation in one-dimensional chains. These complexes show room-temperature photoluminescence. Samarium (III) complexes of picolinic acid (Hpic), 3-hydroxypicolinic acid (HpicOH) and 2-hydroxynicotinic acid (H 2nicO) were prepared and characterised. The crystal structures of the samarium complexes K 2[Sm 2(pic) 6(μ-pic) 2] · 7.5H 2O ( 1), [Sm(picOH) 2(μ-HpicO)(H 2O)] · 3H 2O ( 2) and [Sm(HnicO) 2(μ-HnicO)(H 2O)] · 5H 2O ( 3) were determined by single-crystal X-ray diffraction studies. The coordination modes of the pyridine-carboxylic acids to Sm 3+ centres have been investigated. These complexes showed room-temperature photoluminescence.