Abstract: A bi-photochromic molecule comprises two photochromic moieties linked via a polydialkylsiloxane oligomer. An ophthalmic lens comprises the bi-photochromic molecule. A polymeric host material comprises the bi-photochromic molecule.

Abstract: A photochromic grey coloring 2H-naphtho[1,2-b]pyran of formula (1) wherein R1 is selected from mono-, di- or poly-substituted aryl groups, mono-, di- or poly-substituted naphthyl groups and mono-, di- or poly-substituted heteroaryl groups, wherein at least one substituent is a nitrogen containing group, including amino, C1-C20 and C6-C20 alkylamino, C1-C20 and C6-C20 dialkylamino, C2-C20 dialkenylamino, C2-C20 or C4-C20 di(polyalkenyl)amino, arylamino, diarylamino, C1-C20 alkylarylamino, tetra (C1-C10 linear or branched alkyl) guanidino and cyclic-amino groups and at least one of R7 and R9, which may be the same or different, is selected from C1-C20 N alkylamino C1-C20 N-alkylamido, C1-C20 N,N-dialkylamido, amido, nitro, amino, C1-C20 alkylamino, C1-C20 dialkylamino, C2-C20 dialkenylamino, C4-C20 di(polyalkenyl)amino, arylamino, diarylamino, C1-C20 alkylarylamino, or cyclicamino groups.

Abstract: A photochromic compound has the formula (I) wherein R1 is selected from the group including substituted amino aryl moieties, substituted cyclic amino aryl moieties and substituted N-indolinoaryl or N-tetrahydroquinolino aryl groups, R3 is selected from the group including linear or branched C1-C20 alkyl, linear or branched C2-C20 alkenyl or polyalkenyl, C2-C20 alkynyl or polyalkynyl, aryl, heteroaryl, linear or branched C1-C20 alkyl aryl, linear or branched C1-C20 alkyl-cycloalkyl or -bicycloalkyl or -tricycloalkyl or substituted -cycloalkyl or -bicycloalkyl or -tricycloalkyl, linear or branched C1-C20 haloalkyl or perhaloalkyl, linear or branched C1-C20 alkoxyalkyl or peralkoxyalkyl, linear or branched C1-C20 alkylthioalkyl or peralkylthioalkyl, linear or branched C1-C20 amino alkyl or peraminoalkyl, C3-C20 cycloalkyl or substituted cycloalkyl, C4-C20 bicycloalkyl or substituted bicycloalkyl, C6-C20 tricycloalkyl or substituted tricycloalkl or linear or branched C1-C20 hydroxyalkyl or perhydroxyalkyl; R4 and

Abstract: Red coloring hyperchromic compounds have the formula: where R1 is H, NR2R3, OR4, SR4 or R7 wherein R2 and R3 are alkyl or carbocyclic groups or together with the nitrogen to which they are attached form a heterocyclic ring; R4 is the same as R1 or is alkyl, perhaloallyl, aryl or heteroaryl; R7 is alkyl, haloalkyl, alkylthio, aryl, arylthio, heteroaryl, halogen, nitrile, carboxylate, ester, nitro, or a carbocyclic or heterocyclic ring fused to faces f, gh, i, j or k; and R5 is a cyclic aminoaryl group, an indolinoaryl group, a tricyclic nitrogen heterocycle, or an unsaturated cyclic aminoaryl group.

Abstract: Compositions comprising a naphtho [1,2-b]pyran of formula (I): wherein R7 and/or R9 is hydrogen or an amino group provided that R7 and R9 are not both hydrogen, and the other substituents are as defined in the specifcation.

Abstract: Azophenyl compounds of the formula: ##STR1## wherein R.sub.1 is an o-, p-directing substituent; R.sub.2 is a substituted or unsubstituted .beta.-hydroxyalkyl group; R.sub.3 is an aromatic carbocyclic or heterocyclic group which is mono- or poly-cyclic and is substituted or unsubstituted; and wherein the benzene ring A may contain one or more further substituents. The compounds are useful as dyestuffs (if they are themselves colored) or as intermediates in the preparation of dyestuffs.