Pyrene-Based Approach to Tune Emission Color from Blue to Yellow

The
development of functionalized, luminescent, pyrene-based monomers
has been and continues to be an area of great interest in terms of
the design and fabrication of optical and electronic devices. Herein,
a facile strategy to tune the emission color of pyrene-based chromophores
has been established by simple functional group modification at the para position to the diphenylamino on the donor building
block. Intriguing photophysical properties were obtained and are described
both in different solutions and in the solid state. The results obtained
could be explained by the Hammett method and by density functional
theory (DFT) calculations. A good correlation was observed between
the Hammett σpara constants of the functional groups para to the phenyl and the wavenumber (cm–1) of the emission profile. This positive correlation, namely between
the σ constants of the functional groups and the emission properties
of the monomers, can be used to develop a predictive method for these
types of systems.