Photochemical kinetics measured with sub-picomole sensitivity in hollow-core photonic crystal fibre

21.06.2013, 00:00

Newsletter 6

Applications of photochemistry are emerging in areas such as photo-medicine, artificial photosynthesis and optically switchable media. This is stimulating work on the synthesis and characterization of novel photoactive compounds. Here we use hollow-core photonic crystal fibre (HC-PCF) as an optofluidic microreactor for the measurement of photochemical kinetics. All the hollow channels in the fibre are filled with the liquid solution, light being tightly guided in the central hollow core. The resulting strong interaction has allowed for the first time measurement of the photoisomerisation quantum yields for "push-pull" azobenzenes in solution at room temperature – challenging because of thermal isomerisation is very rapid. The measured isomerisation rate constants are in excellent agreement with those established previously in conventional cuvette-based experiments. An additional advantage of HC-PCF is that the long path-length allows monitoring of photochemical reactions by absorption spectroscopy to unprecedented sub-picomole sensitivities. This enables measurements in solvents in which the dyes are too insoluble to permit conventional cuvette-based measurements.  This work is the result of an on-going collaboration with the group of Dr. Anita Jones in the School of Chemistry at the University of Edinburgh.

Contact: tijmen.euser(at)mpl.mpg(dot)de
Group: Russell Division
Reference: G. O. S. Williams et al., Lab Chip 12, 3356-3361 (2012).