Development of molecular cassettes for the excitation energy transfer in the red region of the spectrum

The development of multichromophoric systems able to achieve efficiently excitation energy transfer (EET) from donors to covalently linked acceptor chromophores (i.e., molecular cassettes) has gained great interest in the last few years, since they are extremely useful in the development of advanced materials for outstanding photonic technologies (including optoelectronics), such as solar harvesting, fluorescence microscopy or biomolecular probing.¹

On the other hand, the emission at longer wavelengths has important applications in Medicine, and thus it is called “the biological or therapeutic window”: In the 650-1000 nm region autofluorescence, and absorption by water, tissues and cells are minimized, and there is less light scattering. This means that deeper penetration by incident laser light can be achieved.²

In our group we have introduced a new design for the achievement of energy transfer in molecular cassettes. This design is based on spiranic O-BODIPY having a polyarene as the donor moiety.³ Based on this new design, we have developed a series of O-BODIPY dyes showing cassette behavior and emitting in the red region of the spectrum (see Figure 1).

References:

1. For example see: Yuan, L.; Weiying, L.; Zheng, K.; Zhu, Z. Acc. Chem. Res. 2013, 46, 1462; Huang, X.; Han, S.; Huang, W.; Sanyang, H.; Xiaogang, L. Chem. Soc. Rev. 2013, 42, 173.
2. Lu, H.; Mack, J.; Yang, Y.; Shen, Z. Chem. Soc. Rev. 2014, 43, 4778.
3. Sánchez-Carnerero, E. M.; Gartzía-Rivero, L.; Moreno, F.; Maroto, B. L.; Agarrabeitia, A. R.; Ortiz, M. J.; Bañuelos, J.; López-Arbeloa, Í.; de la Moya, S. Chem. Commun. 2014, 50, 12765-12767 and references cited therein.