Volume 11 Issue 10
Fates of Microcystis aeruginosa Cells and Associated Microcystins in Sediment and the Effect of Coagulation Process on Them
Xiaoguo Chen,Huiyi Xiang,Yue Hu,Yang Zhang,Liao Ouyang andMeiying Gao
1Facultad de Ciencia Químicas, Universidad Autónoma de Chihuahua, Campus Universitario #2, Apartado Postal 669, Chihuahua 31125, Mexico
2Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico D.F. 04510, Mexico
*Authors to whom correspondence should be addressed
Abstract
A series of pyrene-fullerene C60 dyads bearing pyrene units (PyFC12, PyFPy, Py2FC12 and PyFN) were synthesized and characterized. Their optical properties were studied by absorption and fluorescence spectroscopies. Dyads were designed in this way because the pyrene moeities act as light-harvesting molecules and are able to produce “monomer” (PyFC12) or excimer emission (PyFPy, Py2FC12 and PyFN). The fluorescence spectra of the dyads exhibited a significant decrease in the amount of pyrene monomer and excimer emission, without the appearance of a new emission band due to fullerene C60. The pyrene fluorescence quenching was found to be almost quantitative, ranging between 96%–99% depending on the construct, which is an indication that energy transfer occurred from one of the excited pyrene species to the fullerene C60.
Keywords:
pyrene; excimers; fullerene; fluorescence; energy transfer; photovoltaics