Naphthyl-Containing Organophosphonate Derivatives of Keggin-Type Polyoxotungstates
Ikusi/ Ireki
Data
2016-06Egilea
Andino, Nerea
Artetxe Arretxe, Beñat
Reinoso Crespo, Santiago
Vitoria García, Pablo
Martínez, José Ignacio
Inorganics 4(2) : (2016) // Article ID 14
Laburpena
New organophosphonate derivatives of monovacant Keggin-type polyoxotungstates that contain naphthyl groups have been synthesized and characterized in both solid state and solution. Single-crystal structural analysis shows that two phosphonate groups occupy the vacant position of the lacunary cluster unit in the isostructural compounds [N(C4H9)(4)](3)[H(POC11H9)(2)(-HBW11O39)] (TBA-1) and [N(C4H9)(4)](3)[H(POC11H9)(2)(-SiW11O39)] (TBA-2). Liquid-solution UV-Vis transmittance and solid-state diffuse reflectance spectroscopy studies reveal the presence of a new absorption band in the visible region, the charge transfer character of which has been further confirmed by time-dependent density functional theory (TD-DFT) calculations. The latter evidence that the charge transfer process is dominated by transitions from the highest occupied molecular orbital (HOMO), localized in the aromatic ring of the organic group, to the lowest unoccupied molecular orbital (LUMO), localized in the Keggin anion. Photoluminescence studies show that the fluorescent properties of the 1-naphthylmethylphosphonate group are quenched upon its incorporation into the inorganic oxo-tungstate skeleton. The solution stability of the hybrid clusters has been evaluated by a combination of H-1-, C-13- and P-31-Nuclear Magnetic Resonance spectroscopy and Electrospray Ionization-Mass Spectrometry. The hybrid polyanion [H(POC11H9)(2)(-HBW11O39)](3-) (1) herein constitutes the first structurally characterized organo-p-block containing borotungstate, and hence it confirms that this strategy for the organic functionalization of polyoxometalate clusters can be applied to new platforms belonging to the family of group-13 heteropolyoxotungstates.
Collections
Bestelakorik adierazi ezean, itemaren baimena horrela deskribatzen da:© 2016 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access
article distributed under the terms and conditions of the Creative Commons Attribution
(CC-BY) license (http://creativecommons.org/licenses/by/4.0/).