J.C. Cárdenas, L.A. Castillo, W. Molano, C.A. Sierra, A. Reiber
Universidad de los Andes, Colombia
pp. 88 - 91
Keywords: metal-organic frameworks, post-synthetic modification, phenylenevinylene, conjugated imine derivatives
Since the last decade, Colombia has been experienced a boom in coal mining due to the large amount of environmental licenses granted by the government. The growth of this activity triggered a concern in finding a more effective method for methane sensing, which is still done through traditional methods and represents a risk for miner’s health. For driving this issue, we propose a synergistic effect between the high gas adsorption properties of metal-organic frameworks (MOFs) and the well-known luminescent properties of phenylenevinylene and conjugated imine derivatives. First experiments for the synthesis of the above mentioned MOFs were performed by solvothermal standard conditions using phenylenevinylene and conjugated imine ligands as starting materials. However, the low acidity of the phenylenevinylene ligands as well as their length and low solubility yielded in polycrystalline materials whose structural characterization was not possible. In addition, the instability of the imine derivatives prevented the isolation of the targeted MOFs. Despite these difficulties, a second approach is being developed involving post-synthetic modifications of already isolated and characterized MOFs. For this purpose, MOFs containing modifiable functional groups, as iodide and amino groups, have been synthetized. Once these MOFs were obtained, the next step consists in the post-synthetic modification of the functional groups. In order to obtain the target ligands integrated into the already built framework, palladium catalyzed cross coupling reactions and condensation reactions are used. As soon as the post-synthetic modifications are accomplished, solidstate fluorescence of the MOFs alone and under methane atmosphere will be performed, looking forward to a change in the fluorescence spectra.