Molecular Photonics Laboratory

Synthesis

Much of the synthetic work in the MPL is focussed on the preparation of molecular systems for studying electron/energy transfer and fluorescent compounds for applications in such areas as biomedical imaging, sensing, photosensitizers and driving photocatalytic reactions. The two projects below highlight two recent projects.

Bodipy-based Neural Imaging Agents

Fluorescent voltage sensitive dyes (VSDs) respond to the electrical field gradient within membranes and often comprise of a donor-spacer-acceptor structure. In a vast majority of cases the acceptor group is a quaternized pyridine unit with an alkenyl spacer linking to a nitrogen-based donor. The VSD is by design therefore a salt. We have recently looked into the possibility of using small molecule donor-acceptor dyads as VSDs, focusing primarily on Bodipy-based systems, that display extremely strong ground-state charge transfer character. The dyad JULBD is one such example of a newly tested VSD.1

Highly Fluorescent Dyes

Although there are several types of fluorophores in the literature the quest to find robust, redox active, simple to prepare and highly fluorescent molecular systems still represents a challenge. In a recently published paper we describe the properties of the planar molecule, 1H,3H-Isochromeno[6,5,4-mna]xanthene-1,3-dione (CXD). In a range of solutions the fluorescence quantum yield for CXD is high; 0.96 in THF and an excited-singlet state lifetime of 7.4 ns. The dye is almost perfect for laser excitation at 405 nm and is ideal as a blue light photoinitiator.2


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