Grey coloring photochromic fused pyrans

A photochromic, grey colouring 2H-naphtho[1,2-b]pyran of the formula I

• 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 on substitutent is selected from 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 liner or branched alkyl)guanidino and cyclic-amino groups;
• R2 is selected from phenyl, mono-, di- or poly-substituted aryl groups, unsubstituted, mono-, di- or poly-substituted naphthyl groups, and unsubstituted, mono-, di- or poly-substituted heteroaryl groups, wherein, if substituted, the substituents are selected from those substituents for R1 or are linear or branched C1-C10 or C6-C20 alkyl, C3-C20 cycloalkyl, C2-C20 bicycloalkyl, C5-C10 polycycloalkyl, linear or branched C1-C20 or C6-C20 haloalkyl, linear or branched C1-C20 perhaloalkyl, linear or branched C2-C20 alkenyl, linear or branched C1-C20 polyalkenyl, linear or branched C2-C20 alkynyl, linear or branched C4-C20 polyalkynyl, linear or branched C1-C20 or C6-C20 hydroxyalkyl, C1-C20 polyhydroxyalkyl, linear or branched C1-C20 or C6-C20 alkoxy, linear or branched C1-C20 alkylthio, linear or branched C1-C20 or C6-C20(C1-C10 or C6-C10 alkoxy)alkyl, linear or branched C1-C20(C1-C5 alkylthio)alkyl, phenyl, aryl, heteroaryl, halogen, hydroxyl, formyl, acetyl, nitrile, carboxyl, C1-C10 alkoxycarbonyl, C1-C10 N-alkylamido, C1-C5 N,N-dialkylamido, amido, nitro, arylsulfanyl, aryloxy, arylsulfinyl, arylsulfonyl, linear or branched C1-C20 alkylsulfonyl and di-(C1-C20 alkoxyalkyl)phosphonyl or R1 and/or R2 may also be selected from the fused saturated heterocycles II, III and IV in which n and m are integers between 2 and 5 and are the same or different;
• wherein R13 is selected from linear or branched C1-C20 alkyl, C3-C20 cycloalkyl, C4-C20 bicycloalkyl, C5-C20 polycycloalkyl, linear or branched C1-C20 hydroxyalkyl, linear or branched C1-C20 haloalkyl, linear or branched C1-C20 perhaloalkyl, phenyl, C1-C20 linear or branched alkylsulfonyl, aryl, tosyl, arylsulfonyl, acyl, linear or branched C1-C20 alkylcarbonyl, benzoyl, aroyl, substituted aroyl and butoxycarbonyl.
• R3 is R1 or R2 or is selected from hydrogen, linear or branched C1-C20 alkyl, C3-C20 cycloalkyl, C2-C20 bicycloalkyl, C5-C20 polycycloalkyl linear or branched C1-C20 haloalkyl, linear or branched C1-C20 perhaloalkyl, linear or branched C2-C20 alkenyl, linear or branched or C1-C20 polyalkenyl, linear or branched C2-C20 alkynyl, linear or branched C4-C20 polyalkynyl, linear or branched C1-C20 hydroxyalkyl, linear or branched C1-C20 polyhydroxyalkyl, linear or branched C1-C20 alkoxy, linear or branched C1-C20 alkylthio, linear or branched C1-C20(C1-C10 alkoxy)alkyl, linear or branched C1-C20(C1-C5 alkylthio)alkyl, phenyl, aryl, heteroaryl, halogen, hydroxyl, formyl, acetyl, nitrile, carboxyl, C1-C5 alkoxycarbonyl, C1-C5 N-alkylamido, C1-C5 N,N-dialkylamido, amido and nitro;
• R4 is hydrogen;
• R5 is selected from R2 or from the substituents to the substituted aryl groups, substituted naphthyl groups and substituted heteroaryl groups of R1 and R2, or from linear or branched C1-C20(C1-C10 alkylthio)alkyl, linear or branched C1-C20 alkenoyl, linear or branched C3-C20 alkanoyl, linear or branched C5-C20 polyalkenoyl, benzoyl, aroyl, heteroaroyl, linear or branched C1-C20 alkoxycarbonyl, C1-C20 N-alkylamido and C1-C20 N,N-dialkylamido;
• at least one of R7 and R9, which may be the same or different, is selected from 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, and cyclicamino groups, wherein where only one of R7 or R9 is as defined above, the other group R7 or R9 is selected from those substituents specified for R1, R2, R5, R6, R8 and R10, R6, R8, R10, R11, R12, R14, R15, which may be the same or different, are selected from those substituents of R1, R2, R5 and hydrogen;
• R16 of which there may be one or more, the same or different are each as defined in any of R1 to R15 inclusive or wherein the substituents R5 and R6 or R7 and R8 or R8 and R9 or R9 and R10 are each conjoined by a four carbon unit containing one or more substituents according to R16 to provide benzo fused naphtopyrans;
• wherein said 2H-naptho[1,2-b]pyran exhibits a grey color.