resumo
The hydrothermal reaction between lanthanide salts and residues of (benzene-1,3,5-triyltris(methylene))triphosphonic acid (H(6)bmt) promotes the formation of a new series of isotypical layered lanthanideorganic frameworks (LnOFs), [Ln(2)(H(3)bmt)(2)]center dot H2O [where Ln(3+) = Eu3+ (1), Gd3+ (2), Tb3+ (3), Dy3+ (4), Ho3+ (5), Er3+ (6), Tm3+ (7), and Yb3+ (8)]. The crystal structure was unveiled from powder X-ray diffraction data (both laboratory and synchrotron) in tandem with other characterization techniques (namely thermogravimetry, thermodiffractometry, vibrational spectroscopy, and elemental analysis). It is shown that the lanthanide contraction leads, on average, to a reduction of the average crystallite size, up to the nanometer scale in the case of compound 8. The unique structural features of the (2)(infinity)[Ln(2)(H(3)bmt)(2)] layers are discussed in detail, in particular, the six-coordination environment of the lanthanide cations and its topological relationship with the formation of the first 5,5L4 binodal network based on chelating phosphonate groups.
palavras-chave
COORDINATION POLYMERS; MAGNETIC-PROPERTIES; OXALIC-ACID; CAPTURE; CONTRACTION; COMPLEXES; LUMINESCENCE; TOPOLOGIES; LIGANDS; STORAGE
categoria
Chemistry; Crystallography; Materials Science
autores
Paz, FAA; Vilela, SMF; Tome, JPC
nossos autores
Projectos
agradecimentos
We would like to thank Fundacao para a Ciencia e a Tecnologia (FCT, Portugal), the European Union, QREN, FEDER through Programa Operacional Factores de Competitividade (COMPETE), Laboratorio Associado Centro de Investigacao em Materiais Ceramicos e Compositos, CICECO (FCOMP-01-0124-FEDER-037271; ref. FCT PEst-C/CTM/LA0011/2013), and QOPNA (FCOMP-01-0124-FEDER-037296; ref. FCT PEst-C/QUI/U10062/2013) for their general funding scheme. FCT is also gratefully acknowledged for funding the R&D FCOMP-01-0124-FEDER-041282 (ref. FCT EXPL/CTM-NAN/0013/2013), and for the postdoctoral research scholarship No. SFRH/BPD/94381/2013 (to SMFV). We further wish to thank the European Synchrotron Radiation Facility (ESRF, Grenoble, France) for granting access to the ID31 beamline through the R&D project CH-3692.