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

authors	Firmino, ADG; Mendes, RF; Ananias, D; Vilela, SMF; Carlos, LD; Tome, JPC; Rocha, J; Paz, FAA
nationality	International
journal	INORGANICA CHIMICA ACTA
author keywords	Metal-Organic Frameworks; Lanthanides; Microwave Synthesis; Phosphonic acids; Photoluminescence
keywords	ASSISTED SOLVOTHERMAL SYNTHESIS; BUILDING-BLOCK; MOFS; CATALYSIS; LIGAND; PYRENE; ACID)
abstract	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) (H(8)btp) was combined with lanthanide cations affording the isotypical 2D lanthanide-organic frameworks [Ln(4)(H(6)btp)(2)(H(4)btp)(2)(H(8)btp)(H2O)(16)]center dot 12H(2)O [where Ln(3+) = La3+ (1), (La0.9Eu0.1)(3+) (2) and (La-0.9)(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 {4-8(5))(2){4(2).8(4)}{4(3).8(2).10}(4)(4}(2). Supramolecular pi-pi 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 H(8-x)btp(-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. (C) 2016 Elsevier B.V. All rights reserved.
publisher	ELSEVIER SCIENCE SA
issn	0020-1693
isbn	1873-3255
year published	2017
volume	455
beginning page	584
ending page	594
digital object identifier (doi)	10.1016/j.ica.2016.05.029
web of science category	Chemistry, Inorganic & Nuclear
subject category	Chemistry
unique article identifier	WOS:000390722500028