resumo
The synthesis and structural characterization of two novel trivalent neodymium microporous silicates whose structures are reminiscent of the structure of mineral montregianite of the rhodesite group, and their infrared light-emission properties are reported. The compound KNa2Nd[Si8O19]center dot 5H(2)O (1) crystallizes in the orthorhombic Pmma space group: a = 23.9016(17) angstrom, b = 6.9980(5) angstrom, c = 6.5474(5) angstrom. Heating 1 at 200 degrees C for 40 min affords a new partially dehydrated phase, KNa2Nd[Si8O19]center dot 2.8H(2)O (2), also crystallizing in the orthorhombic Pmma space group: a = 23.923(4) angstrom, b = 6.9950(11) angstrom, c = 6.5474(10) angstrom. -Compound 2 is the hydrated phase with the lowest content of water molecule reported to date in the rhodesite mineral series.
palavras-chave
CRYSTAL-STRUCTURE; HYDRODELHAYELITE; DELHAYELITE; FRAMEWORK
categoria
Crystallography
autores
Munha, RF; Ananias, D; Paz, FAA; Rocha, J
nossos autores
Duarte Ananias
Investigador Auxiliar
Filipe Alexandre Almeida Paz
Investigador Principal
João Rocha
Prof. Catedrático
Rui Munhá
Bolseiro de pós-Doutoramentoagradecimentos
We would like to thank Fundacao para a Ciencia e a Tecnologia (FCT, Portugal), the European Union, QREN, FEDER and COMPETE. This work was developed in the scope of the project CICECO-Aveiro Institute of Materials (Ref. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement. DA and RM acknowledge FCT for post-doc grants SFRH/BPD/95032/2013 and SFRH/BPD/8852/2012. We further wish to thank the two anonymous reviewers of the manuscript for their suggestions and comments.