Centrosymmetric molecular structures are commonly seen in dyes and other colorants as they tend to have relatively narrow bulk EM resonances (lightwave resonance) The elongated, high length to diameter ratio, which is effectively doubled in the centrosymmetric structure, is responsible for what we term "antenna effect" today. The antenna (dye molecule) can be touching or attached to something else (like SiO2, or silver salt, or other metallic oxide) and the charge selectively transferred. Organic dyes used to be the only way to get these long-ish chains (100-500nm or more) but now there are other ways being developed and a ton left to explore.

Many "good" dyes absorb, fluoresce and reradiate at the same time, and there is a lot of what is referred to as excitonic activity. Lightwaves provide the energy and excitons, phonons, electrons all get into the act.

The only reason I learned of this was because I work in centrosymmetric structures like this
http://www.google.com/patents/US6038060