"Luminescent metal-organic frameworks as sensor platforms of toxic compounds"

GERM¨¢N E. GOMEZ; MAR¨ªA DOS SANTOS AFONSO; FEDERICO RONCAROLI; GALO J. A. A. SOLER-ILLIA

California

Conferencia; 5th International Conference on Metal-Organic Frameworks & Open Framework Compounds; 2016

TITLE: Luminescent metal-organic frameworks as sensor platforms for toxic compoundsAUTHORS (FIRST NAME, LAST NAME): Federico Roncaroli4, Germ¨¢n Ernesto Gomez1, Mar¨ªa dos Santos Afonso2, Galo J. A. A. Soler-Illia3INSTITUTIONS (ALL):1. Gerencia de Q¨ªmica, Comisi¨®n Nacional de Energ¨ªa At¨®mica, San Mart¨ªn, Buenos Aires, Argentina.2. INQUIMAE-Departamento de Qu¨ªmica Inorg¨¢nica, Anal¨ªtica y Qu¨ªmica F¨ªsica, Facultad de Ciencias Exactas y Naturales-Universidad de Buenos Aires, Ciudad At¨®noma de Buenos Aires, Argentina.3. Instituto de Nanosistemas, Universidad Nacional de San Mart¨ªn, San Mart¨ªn, Buenos Aires, Argentina.4. Departamento de F¨ªsica de la Materia Condensada, Comisi¨®n Nacional de Energ¨ªa At¨®mica, San Mart¨ªn, Buenos Aires, Argentina.ABSTRACT BODY:Abstract Body: MOFs (Metal Organic Frameworks) offer ideal platforms to develop materials with potentialapplications in areas such as luminescence1, adsortion2 y catalisis3. Some MOFs exhibit luminescence accompanied by hypersensitive signals that could be useful for chemical sensing 4. In this context, we studied the variation of the intensity of Eu3+ and Tb3+ transitions of bi and tridimensional MOFs in the presence of organic molecules and cations of environmental interest. The sensing mechanism was justified in terms of energy transfers between the analytes and the metallic centers. Sensor synthesis.Eu-PSA-10, Tb-PSA, Eu-BPDC y Eu-BTC, were prepared and characterized (FTIR, TGA, PXRD) according to the procedure previously reported5,6,7(PSA = 2-phenylsuccinate, BPDC = 4,4¡¯-biphenylcarboxylate and BTC = 1,3,5-benzenetricarboxylate ). It is expected that those 2D laminar MOFs (Eu-PSA-10 and Tb-PSA) should have different sensor activity in comparison with 3D porous and activated MOFs (Eu-BPDC y Eu-BTC). Sensing experiments employing powder samples. Ultrasonicated suspensions were prepared (1,46 mg.mL-1) of sensors in CH3OH solutions of the analytes (metsulfuron, chlorimuron, chlorpirifos, toluene, Cu2+, Mn2+ y UO22+). The measurements were carried out in a F¨¦ix X32 PTI Xe lamp fluorometer, using 3 mL of the suspensions. Excitations were performed at 393 nm for the Eu-samples, and at 352 nm for theTb-samples. In such sensors, the hypersensitive signals were monitored at 615 nm (5D0¡ú7F2) for Eu3+ and 541 nm (5D4¡ú7F5) for Tb3+. When the relative intensities of Eu-PSA, Eu-BTC and Tb-PSA samples were analyzed, quenching in presence of Cu2+, Mn2+ and UO2 2+ could be detected. This phenomenon can be justified by the electroafinity of such cations. Besides, there is quenching produced by organic molecules. This last process is justified by photo-induced energy transfer (PET) from the analyte to the MOF, due interactions between functional groups from the analyte with the metallic centers. For the case of the 3D porous Eu-BTC, a remarkable quenching was observed when the sensor interacted with metsulfuron and cationic species. However, the Eu3+ signal suffered enhancement in toluene and chlorpirifos, being this behavior the most important to differential selectivity.References1. Allendorf C. A., Bauer, R. K. Bhakta, Houk R. J. T. Chem. Soc. Rev. 2009, 38, 1330-1352.2. Murray L. J., Dinca M., Long J. R. Chem. Soc. Rev. 2009, 38, 1294−314.3. Czaja A. U., Trukhanb N., M¨¹ler U. Chem. Soc. Rev. 2009, 38, 1284-1293.4. Hu Z., J. Deibert B., Li J. Chem. Soc. Rev. 2014, 43, 5815-5840.5. Gomez G. E., Bernini M. C., Brusau E. V., Narda G. E., Vega D., Kaczmarek A. M., Van Deun R., Nazzarro M. Dalton Trans. 2015, 44, 3417-3429.6. Yang J., Yue Q., li G.-D., cao J.-J., Li G.-H., Chen J.-S. Inorg. Chem. 2006, 45, 2857-2865.7. Guo X., Zhu G., Fang Q., Xue M., Tian G., Sun J., Li X., Qiu S. Inorg. Chem., 2005, 55, 3850-3855.