On the way to ?optical doping? of electronically low-dimensional polymer systems with strong charge and spin correlations

We discuss the concept of optical manipulation of the charge and spin density in polymer systems with strong-correlation phenomena by attaching pendant chromophores to the polymer backbone. In the process of identifying suitable functional groups for future inclusion in polymers, we study here boron–nitrogen-linked ferrocene derivatives. We investigate the metal-to-ligand charge transfer between a ferrocene donor and π-acceptor units across the B–N bridges. On the basis of photophysical measurements, including picosecond time-resolved spectroscopy, we identify that the initial relaxation of the excited states depends critically on the degree of structural rigidity, and can be tuned by more than an order of magnitude (∼20–800 ps).