| abstract |
The invention concerns photochromic compounds having formula (I), where R1 is a polycyclic group formed by at least one alicyclic group linked to, bridged or condensed, with at least one other aliphatic and/or aromatic ring, which rings contain, optionally, at least one heteroatom and/or at least one unsaturation, R2-R7 can have different meanings, A represents a (hetero)aromatic ring which can be substituted and n is a whole number. Preferably, R1 is an asymmetric bicyclic group such as a norbornyl group. Application to the production of photochromic articles of organic polymers, notably lenses. |