abstract |
Derivatives of fluorene, including ester derivatives of cyano(9H-fluoren-9-ylidene) acetic acid, and sunscreen compositions including a mixture of a photoactive compound and an ester derivative of cyano(9H-fluoren-9-ylidene) acetic chain with an ester derivative of cyano(9H-fluoren-9-ylidene) acetic acid and methods of filtering out ultra-violet light from a substrate by the use of one or more such derivatives. |