Photochromic spirodihydrophenanthropyrans

A photochromic spirodihydrophenanthropyran compound corresponding to formula I:

• wherein
• R1, R2, R3 and R4 each independently represent a substituent, selected from the group α, consisting of hydrogen;
• (C1-C6)-alkyl;
• (C1-C6)-thioalkyl;
• (C3-C7)-cycloalkyl which optionally may contain one or more heteroatoms;
• (C1-C6)-alkoxy;
• hydroxyl;
• trifluoromethyl;
• bromine;
• chlorine;
• fluorine;
• and unsubstituted, monosubstituted or disubstituted phenyl, phenoxy, benzyl, benzyloxy, naphthyl or naphthoxy, wherein the substituents are selected from the group α;
• or
• R1 and R2, or R3 and R4, or both, form a -A-(CH2)k-D group or -A-(C(CH3)2)k-D group bonded to the aromatic ring and wherein k=1 or 2, and A and D are independently selected from the group consisting of oxygen, sulfur, CH2, C(CH3)2 and C(C6H5)2, and wherein the -A-(CH2)k-D group optionally may have a benzo ring annellated thereto;
• or
• R1 and R2, or R3 and R4, or both, independently represent an unsubstituted, monosubstituted, or disubstituted benzo or pyrido ring, which is annellated to the phenanthrene unit, wherein the substituents are selected from the group α;
• R5 and R6, or R7 and R8, or both, are independently selected from the group α, with the proviso that either R5 and R6, or R7 and R8, together with the spiro carbon atom to which they are attached form a 3 to 8 membered carbocyclic or heteromonocyclic spiro ring, which optionally may carry one or more substituents selected from the group α, and to which one to three aromatic or heteroaromatic ring systems optionally may be annellated, wherein the ring systems are independently selected from the group β, consisting of benzene, naphthalene, phenanthrene, pyridine, quinoline, furan, thiophene, pyrrol, benzofuran, benzothiophene, indol and carbazol, wherein said ring systems optionally may be substituted with one or more substituents selected from the group α, and wherein two vicinal annellated ring systems optionally may also be linked together by an ortho, ortho′ bridge, or
• with the proviso that either R5 and R6, or R7 and R8, or both, together with the spiro carbon atom to which they are attached form a 7 to 12 membered carbo-bicyclic spiro ring or a 7 to 12 membered carbo-tricyclic spiro ring, each of which optionally may carry one or more substituents selected from the group α,
• B and B′ are independently selected from following groups a), b) and c), wherein
• a) consists of mono-, di- and trisubstituted aryl groups selected from the group consisting of phenyl, naphthyl and phenanthryl;
• b) consists of unsubstituted, monosubstituted and disubstituted heteroaryl groups selected from the group consisting of pyridyl, furanyl, benzofuranyl, thienyl, benzothienyl, 1,2,3,4-tetrahydrocarbazolyl and julolidinyl;
• wherein the substituents of the aryl or heteroaryl groups in a) and b) are selected from the group α or the group χ, consisting of hydroxyl;
• 2-phenylethenyl which is unsubstituted, monosubstituted or disubstituted at the phenyl ring;
• (phenylimino)methylene which is unsubstituted, monosubstituted or disubstituted at the phenyl ring;
• (phenylmethylene)imino which is unsubstituted, monosubstituted or disubstituted at the phenyl ring;
• amino;
• mono-(C1-C6)-alkylamino;
• di-(C1-C6) alkylamino;
• mono and diphenylamino which are unsubstituted, monosubstituted or disubstituted at the phenyl ring;
• piperidinyl;
• N-substituted piperzinyl;
• pyrrolidinyl;
• imidazolidinyl;
• pyrazolidinyl;
• indolinyl;
• morpholinyl;
• 2,6-dimethylmorpholinyl;
• thiomorpholinyl;
• azacycloheptyl;
• azacycloctyl;
• unsubstituted, monosubstituted or disubstituted phenothiazinyl;
• unsubstituted, monosubstituted or disubstituted phenoxazinyl;
• unsubstituted, monosubstituted or disubstituted 1,2,3,4-tetrahydroquinolinyl;
• unsubstituted, mono-substituted or disubstituted 2,3-dihydro-1,4-benzoxazinyl;
• unsubstituted, monosubstituted or disubstituted 1,2,3,4-tetrahydroisoquinolinyl;
• unsubstituted, monosubstituted or disubstituted phenazinyl;
• unsubstituted, monosubstituted or disubstituted carbazolyl;
• unsubstituted, monosubstituted or disubstituted 1,2,3,4-tetrahydrocarbazolyl;
• and unsubstituted, monosubstituted or disubstituted 10,11-dihydrodibenz[b,f]azepinyl;
• wherein the substituent(s) are independently selected from the group consisting of (C1-C6)-alkyl, (C1-C6)-alkoxy, bromine, chlorine, and fluorine;
• or
• wherein two directly vicinal substituents represent a Y—(CX2)p—Z grouping, where p=1, 2 or 3;
• X represents hydrogen, CH3, or C6H5, and Y and Z each independently represent oxygen, sulfur, N(C1-C6)-alkyl, N—C6H5, CH2, C(CH3)2, or C(C6H5)2, wherein two or more adjacent carbon atoms of this Y—(CX2)p—Z grouping may be, each independently of one another, also part of a benzo ring system, which is annellated thereto and each of which in turn optionally may carry one or more substituents, selected from the group α or the group χ;
• or
• c) B and B′ together with the adjacent carbon atom of the pyran ring form an unsubstituted, monosubstituted or disubstituted 9,10-dihydroanthracene, fluorene, thioanthene, xanthene, benzo[b]fluorene, 5H-dibenzo[a,d]cycloheptene or dibenzosuberone group or a saturated hydrocarbon group which is (C3-C12) spiro monocyclic, (C7-C12) spiro bicyclic or (C7-C12) spiro tricyclic, wherein the substituents of the unsaturated cycles are independently selected from the group α or the group χ.