Terminal Terthiophenediones: Fast-Decay Fluorescent Dyes and Their Efficient Syntheses

[Image: see text] Terminally acylated terthiophenes, in particular, the bis-pivaloyl derivative, were synthesized by Friedel–Crafts acylation with sub-stoichiometric amounts of standard zinc oxide and exhibit strong fluorescence and an ultrafast fluorescence decay of 400 ps. Their high photostability and large Stokes’ shifts are good prerequisites for applications in optical GBit fast data systems such as fiber optics in slip rings.