[3.3]‐ and [4.4](2,7)Pyrenophanes as Excimer Models: Synthesis, Molecular Structure, and Spectroscopic Properties

As excimer models the [3.3]‐ and [4.4]pyrenophanes 1 and 2 were synthesized. As the key precursor for the synthesis of 1 the octahydro‐dithia[4.4]pyrenophane 9 was obtained by cyclisation of 4 and 8 , the syntheses of which are described. Disulfone 10 , derived from 9 , on vapour‐phase pyrolysis yielded 11 which by dehydrogenation was converted into 1 . In an analogous route 2 was obtained via 16, 17 , and 18 starting from 4 and 15 (prepared in the reaction sequence 12 → 13 → 14 → 15 ). – The molecular structures of 1 and 2 , determined by X‐ray structure analyses, are discussed with regard to transanular distances and deviations from planarity of the pyrene units. – Absorption spectra of 1 and 2 are discussed with reference to transanular interactions. The fluorescence emissions of 1 and 2 are found to be ‘excimer‐like’. Results obtained by ODMR measurements of 1 are reported.