TITLE:
A Sustainable Preparation of Functional Perylenophanes by Domino Metathesis
AUTHORS:
Heinz Langhals, Maximilian Rauscher, Peter Mayer
KEYWORDS:
Optical Materials, Functional Dyes, Fluorescence, Exciton Interaction, Metathesis
JOURNAL NAME:
Green and Sustainable Chemistry,
Vol.9 No.2,
May
31,
2019
ABSTRACT: A sustainable four-step synthesis of soluble perylenophanes for applications as fluorescent optical functional materials is presented and even allows upscaling because of starting with technical bulk products. Thus, terminal alkenylnitriles were alkylated reduced to amines, condensed with perylenetetracarboxylic bisanhydride and cyclised to cyclophanes by means of double cross metathesis in yields until 69% of isolated dyes. The first metathesis by means of the second-generation Hoveyda-Grubbs-catalyst brings the remaining reactive olefinic groups close together favouring the ring-closure to the cyclophanes where the locked neighboring of chromophores in a skew arrangement induce strong exciton interactions. The latter cause an increased the Stokes’ separation by means of a moderate hypsochromic shift of light absorption and a stronger bathochromic shift of fluorescence. Various applications such as for lasers, photonics, solar collectors or in analytics are discussed.