A photochromic article comprising a polymeric organic host material and a photochromic amount of a phenanthropyran compound represented by one of the following graphic formulae:
- ##STR14## wherein, (a) R.sub.1 is the group, --CH.sub.2 X or --C(O)Y, wherein X is hydroxy, benzoyloxy, C.sub.1 -C.sub.6 alkoxy, C.sub.1 -C.sub.6 acyloxy, C.sub.2 -C.sub.6 dialkylamino, or trimethylsilyloxy, Y is the group, --OR.sub.4 or --N(R.sub.5)R.sub.6, wherein R.sub.4 is hydrogen, C.sub.1 -C.sub.6 alkyl, phenyl, mono(C.sub.1 -C.sub.6)alkyl substituted phenyl, mono (C.sub.1 -C.sub.6) alkoxy substituted phenyl, phenyl (C.sub.1 -C.sub.3) alkyl, mono (C.sub.1 -C.sub.6) alkyl substituted phenyl (C.sub.1 -C.sub.3) alkyl, mono (C.sub.1 -C.sub.6) alkoxy substituted phenyl (C.sub.1 -C.sub.3) alkyl, C.sub.1 -C.sub.6 alkoxy(C.sub.2 -C.sub.4) alkyl, or C.sub.1 -C.sub.6 haloalkyl, R.sub.5 and R.sub.6 are each selected from the group consisting of hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.5 -C.sub.7 cycloalkyl, phenyl, mono-substituted phenyl, and di-substituted phenyl, or R.sub.5 and R.sub.6 together with the nitrogen atom form an unsubstituted, mono-substituted, or di-substituted heterocyclic ring containing from 5 to 6 ring atoms, which heterocyclic ring has said nitrogen atom as the sole hetero atom, said phenyl and heterocyclic ring substituents being C.sub.1 -C.sub.6 alkyl or C.sub.1 -C.sub.6 alkoxy, said halo substituent being chloro or fluoro;
- (b) R.sub.2 is hydrogen, C.sub.1 -C.sub.6 alkyl, C.sub.3 -C.sub.7 cycloalkyl, pyridyl, phenyl, mono-substituted or di-substituted phenyl, said phenyl substituents being C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 alkoxy, chloro, or fluoro;
- (c) each R.sub.3 is chloro, fluoro, amino, C.sub.1 -C.sub.6 monoalkylamino, C.sub.2 -C.sub.6 dialkylamino, C.sub.1 -C.sub.6 alkyl, or --OR.sub.7, wherein R.sub.7 is hydrogen, C.sub.1 -C.sub.6 alkyl, allyl, or acetyl, and n is the integer 0, 1, or 2;
- and
- (d) B and B' are each selected from the group consisting of:
- (i) the unsubstituted, and the mono-, di-, or tri-substituted aryl groups phenyl and naphthyl;
- (ii) the substituted or unsubstituted heterocyclic aromatic groups pyridyl, furanyl, benzofuranyl, thienyl, and benzothienyl, said aryl and heterocyclic substituents being selected from the group consisting of hydroxy, amino, C.sub.1 -C.sub.6 monoalkylamino, C.sub.2 -C.sub.6 dialkylamino, C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 haloalkyl, C.sub.1 -C.sub.6 alkoxy, mono(C.sub.1 -C.sub.6)alkoxy(C.sub.1 -C.sub.4)alkyl, acryloxy, methacryloxy, and halogen, said halogen or (halo) group being fluoro or chloro;
- (iii) the groups represented by the following graphic formulae:
- ##STR15## wherein A is carbon or oxygen and B is oxygen or substituted nitrogen, provided that when B is substituted nitrogen, A is carbon, said nitrogen substituents being selected from the group consisting of hydrogen, C.sub.1 -C.sub.6 alkyl, and C.sub.2 -C.sub.6 acyl;
- each R.sub.8 is C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 alkoxy, hydroxy, or halogen, said halogen being chloro or fluoro;
- R.sub.9 and R.sub.10 are each hydrogen or C.sub.1 -C.sub.6 alkyl;
- and m is the integer 0, 1, or 2;
- and
- (iv) C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 haloalkyl, C.sub.1 -C.sub.6 alkoxy(C.sub.1 -C.sub.4)alkyl, C.sub.3 -C.sub.6 cycloalkyl, mono(C.sub.1 -C.sub.6) alkoxy(C.sub.3 -C.sub.6)cycloalkyl, mono(C.sub.1 -C.sub.6)alkyl(C.sub.3 -C.sub.6)cycloalkyl, and halo(C.sub.3 -C.sub.6)cycloalkyl, said halo group being fluoro or chloro;
- and
- (v) B and B' taken together form a substituted or unsubstituted fluoren-9-ylidene or a substituted or unsubstituted, saturated bicyclic ring selected from the group consisting of adamantylidene, bornylidene, norbornylidene, and bicyclo(3.3.1)nonan-9-ylidene.