Designing Near-Infrared and Visible Light Emitters by Postsynthetic Modification of Ln(+3)-IRMOF-3

authors	Abdelhameed, RM; Carlos, LD; Rabu, P; Santos, SM; Silva, AMS; Rocha, J
nationality	International
journal	EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
author keywords	Metal-organic frameworks; Luminescence; Magnetic properties; Lanthanides; Postsynthetic modification
keywords	METAL-ORGANIC FRAMEWORKS; LANTHANIDE COORDINATION POLYMERS; 2ND-ORDER ZEEMAN TERMS; RARE-EARTH; MAGNETIC-PROPERTIES; PARAMAGNETIC-SUSCEPTIBILITY; LUMINESCENCE PROPERTIES; HYDROTHERMAL SYNTHESIS; INORGANIC HYBRIDS; COMPLEXES
abstract	The postsynthetic modification of metal-organic frameworks is a promising new route for engineering optical centres and tuning the light emission properties of materials. Here, the postsynthetic modification of isoreticular metal-organic framework-3 (IRMOF-3) with ethyl oxalyl monochloride and ethyl acetoacetate followed by the chelation of trivalent lanthanide ions afforded efficient near-infrared (Nd3+) and visible (Eu3+ and Tb3+) light emitters. IRMOF-3 was used as an example owing to its highly porous crystalline structure and the presence of non-coordinating amino groups on the benzenedicarboxylate (bdc) linker, which are amenable to modification. The conversion of the amino groups was 100 and 65% for ethyl oxalyl monochloride and ethyl acetoacetate, respectively. The materials were characterised by elemental analysis, powder X-ray diffraction, optical and scanning electron microscopy, Fourier transform infrared spectroscopy, and solution (H-1) and (C-13) solid-state nuclear magnetic resonance spectroscopy. The solid-state luminescence properties of Ln-modified IRMOF-3 were investigated at room temperature. The presence of the bdc aromatic ring, beta-diketonates and oxamate enhanced the Ln(3+) sensitization through ligand-to-metal energy transfer. The magnetic behaviour of all compounds was further analysed. The spin-orbit coupling and zero-field splitting parameters were evaluated by fitting the experimental magnetic susceptibility to the analytical expressions for the free Ln(3+) ions.
publisher	WILEY-V C H VERLAG GMBH
issn	1434-1948
year published	2014
issue	31
beginning page	5285
ending page	5295
digital object identifier (doi)	10.1002/ejic.201402789
web of science category	Chemistry, Inorganic & Nuclear
subject category	Chemistry
unique article identifier	WOS:000344791100004