Microwave Synthesis of a photoluminescent Metal-Organic Framework based on a rigid tetraphosphonate linker

Autor: Filipe A. Almeida Paz, Duarte Ananias, Ana D. G. Firmino, João P. C. Tomé, Sérgio M. F. Vilela, Luís D. Carlos, Ricardo F. Mendes, João Rocha
Rok vydání: 2017
Předmět:
Zdroj: Inorganica Chimica Acta. 455:584-594
ISSN: 0020-1693
DOI: 10.1016/j.ica.2016.05.029
Popis: In this manuscript, microwave-assisted synthesis was used to prepare a new organic building block and a Metal-Organic Framework based on this unit. The tetrapodal organic linker [1,1′-biphenyl]-3,3′,5,5′-tetrayltetrakis(phosphonic acid) (H8btp) was combined with lanthanide cations affording the isotypical 2D lanthanide-organic frameworks [Ln4(H6btp)2(H4btp)2(H8btp)(H2O)16]·12H2O [where Ln3+ = La3+ (1), (La0.9Eu0.1)3+ (2) and (La0.9Tb0.1)3+ (3)]. 1 was isolated as large single-crystals and its crystal structure was solved by single-crystal X-ray diffraction. Phase identification of the Eu3+- (2) and Tb3+-based (3) materials was performed by powder X-ray diffraction. Compound 1 consists of two-dimensional double-deck layers, characterized by an unprecedented tetranodal 2,4,4,4-connected layered network, with total point symbol {4·85}2{42·84}{43·82·10}4{4}2. Supramolecular π–π interactions exist both within and between layers. 1–3 were fully characterized in the solid-state by a plethora of techniques [elemental and thermogravimetric analyses, electron microscopy (SEM and EDS), FT-IR spectroscopy and solid-state NMR]. Photoluminescence properties of the optically-active mixed-lanthanide materials 2 and 3 reveal that the employed H8−xbtp−x residues are better suited to sensitize Tb3+ than Eu3+, with the measured lifetimes being of 0.83 ± 0.01 and 0.22 ± 0.01 ms, respectively.
Databáze: OpenAIRE
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