resumo
[Gd(H(4)nmp)(H2O)(2)]Cl center dot 2H(2)O (1) converts into [Gd-2(H(3)nmp)(2)]center dot xH(2)O (2) (x= 1 to 4) with a notable increase in proton conductivity.1is a charged layered material counter balanced by chloride ions, with proton conductivity values of 1.23 x 10(-5)S cm(-1)at 98% relative humidity (RH) and 40 degrees C. At 98% RH and 94 degrees C the observed conductivity is 0.51 S cm(-1), being to date one of the highest values ever reported for a proton-conducting coordination polymer. This increase is observed during a structural transformation into2that occurs at high temperature and RH. While this remarkable conductivity is observed only after transformation and by maintaining high humidity conditions, as-synthesized2also shows a conductivity value of 3.79 x 10(-2)S cm(-1)at 94 degrees C and 98% RH, still ranked as one of the highest reported values. Moreover, it is shown that the key factor for high proton conduction is the unusual dynamic structural transformation with water insertion and release of chloride ions.
palavras-chave
METAL-ORGANIC FRAMEWORKS; LUMINESCENT; CONDUCTORS; DESIGN; MOF
categoria
Chemistry
autores
Mendes, RF; Barbosa, P; Domingues, EM; Silva, P; Figueiredo, F; Paz, FAA
nossos autores
Grupos
G1 - Materiais Porosos e Nanossistemas
G3 - Materiais Eletroquímicos, Interfaces e Revestimentos
agradecimentos
We wish to thank Fundacao para a Ciencia e a Tecnologia (FCT, Portugal), the European Union, QREN, FEDER through Programa Operacional Factores de Competitividade (COMPETE), UniRCell (SAICTPAC/0032/2015 and POCI-01-0145-FEDER-016422) and CICECO-Aveiro Institute of Materials (FCT Ref. UIDB/50011/2020 & UIDP/50011/2020), financed by national funds through the FCT/MEC and appropriately co-financed by FEDER under the PT2020 Partnership Agreement. FCT is also gratefully acknowledged for the PhD grant no. SFRH/BD/46601/2008 (to PS), and the Development grant no. IF/01174/2013 (to FF). RFM also gratefully acknowledges FCT for the Junior Research Position (CEECIND/00553/2017).