title: Single-molecule-magnet behavior in the family of [Ln(OETAP)2] double-decker complexes (Ln=lanthanide, OETAP=octa(ethyl)tetraazaporphyrin).
abstract: Double-decker complexes of lanthanide cations can be readily prepared with tetraazaporphyrins (porphyrazines). We have synthesized and characterized a series of neutral double-decker complexes [Ln(OETAP)2 ] (Ln=Tb(3+), Dy(3+), Gd(3+), Y(3+); OETAP=octa(ethyl)tetraazaporphyrin). Some of these complexes show analogous magnetic features to their phthalocyanine (Pc) counterparts. The Tb(3+) and Dy(3+) derivatives exhibit single-molecule magnet (SMM) behavior with high blocking temperatures over 50 and 10 K, respectively. These results confirm that, in double-decker complexes that involve Tb or Dy, the (N4)2 square antiprism coordination mode has an important role in inducing very large activation energies for magnetization reversal. In contrast with their Pc counterparts, the use of tetraazaporphyrin ligands endows the presented [Ln(OETAP)2] complexes with extraordinary chemical versatility. The double-decker complexes that exhibit SMM behavior are highly soluble in common organic solvents, and easily processable even through sublimation.
authors.affiliation: Institute of Chemical Research of Catalonia (ICIQ), Av. Països Catalans, 16, 43007, Tarragona (Spain), Fax: (+34) 977-920-224.
authors.forename: Nelson
authors.initials: N
authors.lastname: Giménez-Agulló
authors.forename: Cristina Sáenz
authors.initials: CS
authors.lastname: de Pipaón
authors.forename: Louis
authors.initials: L
authors.lastname: Adriaenssens
authors.forename: Marta
authors.initials: M
authors.lastname: Filibian
authors.forename: Marta
authors.initials: M
authors.lastname: Martínez-Belmonte
authors.forename: Eduardo C
authors.initials: EC
authors.lastname: Escudero-Adán
authors.forename: Pietro
authors.initials: P
authors.lastname: Carretta
authors.forename: Pablo
authors.initials: P
authors.lastname: Ballester
authors.forename: José Ramón
authors.initials: JR
authors.lastname: Galán-Mascarós
keywords: NMR spectroscopy; lanthanides; magnetic properties; porphyrinoids; sandwich complexes