Proton conductivity and luminiscence properties of lanthanide aminotriphosphonates
Bazaga-García, Montse,Angeli, Giasemi K.,Papathanasiou, Konstantinos E.,Salcedo, Inés R.,Olivera-Pastor, Pascual,Losilla, Enrique R.,Choquesillo-Lazarte, Duane,Hix, Gary B.,Cabeza-Díaz, Aurelio,Demadis, Konstantinos D.
- Published
- 2016
- Language
- en
Abstract
Metal phosphonates are multifunctional solids with tunable properties, such as internal H-bond networks, and high chemical and thermal stability [1]. In the present work, we describe the synthesis, structural characterization, luminescent properties and proton conduction performance of a new family of isostructural cationic compounds with general formula [Ln(H4NMP)(H2O)2]Cl·2H2O [Ln = La3+, Pr3+, Sm3+, Gd3+, Tb3+, Dy3+, Ho3+, H6NMP = nitrilotris(methylphosphonic acid)]. These solids are formed by positively charge layers, which consist of isolated LnO8 polyhedra and bridge chelating NMP2- ligands, held apart by chloride ions and water molecules. This arrangement result in extended interlayer hydrogen networks with possible proton transfer pathways. The proton conductivity of Gd3+ sample, selected as prototype of the series, was measured. In the range between range 25º and 80 ºC, the conductivity increase with the temperature up to a maximum value of 3.10-4 S·cm-1, at relative humidity of 95 %. The activation energy obtained from the Arrhenius plot (Figure 1) is in the range corresponding to a Grotthuss transfer mechanism.
Full text
PROTON CONDUCTIVITY AND LUMINISCENCE PROPERTIES OF LANTHANIDE AMINOTRIPHOSPHONATES Montse Bazaga-García,a Giasemi K. Angeli,b Konstantinos E. Papathanasiou,b Inés R. Salcedo,a Pascual Olivera-Pastor,a Enrique R. Losilla,a Duane Choquesillo-Lazarte,c Gary B. Hix,d Aurelio Cabeza,a and Konstantinos D. Demadisb m.baz[email protected] aDepartamento de Química Inorgánica, Universidad de Málaga, Málaga, Spain bCrystal Engineering, Growth and Design Laboratory, Department of Chemistry, University of Crete, Crete, Greece cLaboratorio de Estudios Cristalográficos, IACT-CSIC, Granada, Spain dSchool of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, United Kingdom Metal phosphonates are multifunctional solids with tunable properties, such as internal H-bond networks, and high chemical and thermal stability [1]. In the present work, we describe the synthesis, structural characterization, luminescent properties and proton conduction performance of a new family of isostructural cationic compounds with general formula [Ln(H4NMP)(H2O)2]Cl·2H2O [Ln = La3+, Pr3+, Sm3+, Gd3+, Tb3+, Dy3+, Ho3+, H6NMP = nitrilotris(methylphosphonic acid)]. These solids are formed by positively charge layers, which consist of isolated LnO8 polyhedra and bridge chelating NMP2ligands, held apart by chloride ions and water molecules. This arrangement result in extended interlayer hydrogen networks with possible proton transfer pathways. 0.0 2.0x1044.0x104 0.0 2.0x104 4.0x104 2.8 3.0 3.2 3.4 10-6 10-5 10-4 10-3 80 60 40 20 (S·cm-1) Z" ( · cm) Z' ( · cm) Ea= 0.49 eV Temperature (ºC) 1000/T (K-1) The proton conductivity of Gd3+ sample, selected as prototype of the series, was measured. In the range between range 25º and 80 ºC, the conductivity increase with the temperature up to a maximum value of 3.10-4 S·cm-1, at relative humidity of 95 %. The activation energy obtained from the Arrhenius plot (Figure 1) is in the range corresponding to a Grotthuss transfer mechanism. Figure 1: Complex impedance plane plot for Gd3+ compound at 70 ºC and 95% RH. The inset shows the Arrhenius plot. References [1] Ramaswamy, P.; Wong, N. E.; Shimizu, G. K. H. Chem. Soc. Rev., 2014, 43, 5913−5932.
