| abstract |
The invention concerns photochromic compounds corresponding to the formula (I) wherein: Th2 represents a bithienyl group in one among positions 5, 6, 8-10 of the naphthenic cycle; R<1> represents a bithienyl or trithienyl group; and R<2> represents a bithienyl, trithienyl, aryl, naphthyl, thienyl, furanyl, pyrrolyl or N-alkyl pyrrolyl group. The invention is useful for making glazing for buildings, windscreen, helmet visor and glasses for spectacles. |