Synthesis and characterization of fluorophores for the detection of lanthanides and actinides
A series of fluorophores based in the boron dipyrromethene (BODIPY) family were synthesized and characterized. These fluorophores have the capacity of being introduced to a carbamoyl methyl phosphine oxide (CMPO) lanthanide/actinide extractant. These blue, green and red emission fluorophores show high thermal/moisture stability and high fluorescence efficiencies. The fluorescence intensity seems to be dependent on the restricted rotation about the C(8)-C bond in 8-Ph-BODIPY. By taking advantage of this feature, a hydroxyl- containing BODIPY with high fluorescence intensity was synthesized to be incorporated to a CMPO carboxylic acid via esterification. Unfortunately, we did not observe an optical response upon the coordination of the single CMPO-fluorophore ligand to various lanthanides. The generality of the reaction between primary amines and secondary amines and 8-MeS-BODIPY is also discussed along with the optical properties of the new amino-BODIPY fluorophores. The most important feature observed was the significant dependence of their fluorescence intensity with respect to solvent polarity variation. Following the same nucleophilic substitution type of reaction, we explored the generality of nucleophilic substitution of 8-MeS-BODIPY by several alkyl- and aryl- thiols under mild conditions. We also observed that polysubstitution is possible by changing the solvent. The optical features and x-ray crystal structures are herein described. Lastly, a mass spectrometric - collision-induced dissociation (MS-CID) study of lanthanides and various CMPOs is described. It was found that a tridentate CMPO has the capacity to form bis(ligand), nitrate-free complexes with several lanthanides.
Roacho, Robinson, "Synthesis and characterization of fluorophores for the detection of lanthanides and actinides" (2014). ETD Collection for University of Texas, El Paso. AAI3627074.