Photochromic compound and articles containing the same

A photochromic composition comprising a transparent organic host material containing a photochromic amount of a photochromic compound represented by the graphic formula:

• ##STR16## (a) B is a benzene ring fused at the e or g face and X is carbon or nitrogen;
• (b) R.sub.1 is selected from the group consisting of C.sub.1 -C.sub.8 alkyl, phen (C.sub.1 -C.sub.4) alkyl, allyl, acrylyl, methacrylyl, carboxy (C.sub.2 -C.sub.6) alkyl, cyano (C.sub.2 -C.sub.6) alkyl, hydroxy C.sub.2 -C.sub.6 alkyl, and (C.sub.1 -C.sub.4) acyloxy (C.sub.2 -C.sub.6) alkyl;
• (c) R.sub.2 and R.sub.3 are each selected from the group consisting of C.sub.1 -C.sub.5 alkyl, phenyl, mono- and di- substituted phenyl, and phen (C.sub.1 -C.sub.4) alkyl, or combine to form an alicyclic ring containing from 6 to 8 carbon atoms (including the spiro carbon atom), said phenyl substituents being selected from C.sub.1 -C.sub.5 alkyl and C.sub.1 -C.sub.5 alkoxy;
• (d) each R.sub.4 is selected from the group consisting of halogen, C.sub.1 -C.sub.5 alkyl, C.sub.1 -C.sub.5 alkoxy, nitro, cyano, thiocyano, C.sub.1 -C.sub.4 monohaloalkyl, C.sub.1 -C.sub.2 polyhaloalkyl, and mono- and di(C.sub.1 -C.sub.4) alkylamino when X is carbon;
• and is selected from the group consisting of C.sub.1 -C.sub.5 alkyl, C.sub.1 -C.sub.5 alkoxy and halogen when X is nitrogen;
• (e) R.sub.5 is selected from the group consisting of hydrogen, halogen, C.sub.1 -C.sub.5 alkyl, C.sub.1 -C.sub.5 alkoxy, C.sub.1 -C.sub.4 monohaloalkyl, C.sub.1 -C.sub.2 polyhaloalkyl, cyano and C.sub.1 -C.sub.8 alkoxycarbonyl;
• (f) each R.sub.6 is selected from the group consisting of halogen, C.sub.1 -C.sub.5 alkyl, C.sub.1 -C.sub.5 alkoxy, cyano, C.sub.1 -C.sub.8 alkoxycarbonyl, C.sub.1 -C.sub.4 monohaloalkyl, C.sub.1 -C.sub.2 polyhaloalkyl, and mono- or di(C.sub.1 -C.sub.4) alkylamino;
• and
• (g) e and c are each integers of from 0 to 2.

A photochromic article comprising a solid transparent polymerized organic host material selected from the group consisting of polycarbonate, polymers of polyol(allyl carbonate), polymethylmethacrylate, cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, polystyrene, poly(styrene-metylmethacrylate) copolymer, and poly(styrene-acrylonitrile) copolymer, containing a photochromic amount of a photochromic compound represented by the graphic formula:

• ##STR17## wherein:
• (a) ring B is a benzene ring fused at the e or g face of the indoline moiety and X is carbon or nitrogen;
• (b) R.sub.1 is C.sub.1 -C.sub.4 alkyl, cyano(C.sub.2 -C.sub.4) alkyl or allyl:
• (c) R.sub.2 and R.sub.3 are each C.sub.1 -C.sub.5 alkyl or phenyl;
• (d) each R.sub.4 is C.sub.1 -C.sub.2 alkyl, C.sub.1 -C.sub.2 alkoxy, chloro, fluoro, bromo, nitro or trifluoromethyl when X is carbon;
• and is C.sub.1 -C.sub.2 alkyl, C.sub.1 -C.sub.2 alkoxy, chloro, fluoro, or bromo when X is nitrogen;
• (e) R.sub.5 is hydrogen, fluoro, trifluoromethyl or C.sub.1 -C.sub.2 alkyl;
• (f) R.sub.6 is fluoro, trifluoromethyl, C.sub.1 -C.sub.2 alkyl, or C.sub.1 -C.sub.2 alkoxy;
• and
• (g) e is 0 to 2, and c is 0 to 1.