Abstract
The uv absorption spectrum of thiazolo[5,4-d]thiazole has been investigated for the vapour phase and by means of the linear dichroism of single crystals and liquid crystalline solutions. Two intense π* ← π electronic transitions are observed in the region of the near uv, while a Rydberg transition occurs around 50,000 cm−1 in the vapour spectrum. These results are substantiated by MCD spectroscopy and a comparison with data for the parent molecule thieno[3,2-b]thiophen is given.