NOVELTY - Organic electroluminescent fluorene derivatives (I) are new.    USE - (I) is useful in the organic electroluminescent devices including organic electroluminescent displays and organic solar cells (all claimed).    ADVANTAGE - (I) exhibits high luminous efficiency in blue color and excellent life property of material, and thus provides organic electroluminescent device having very good operation life and appropriate color coordinate with high color purity.    DETAILED DESCRIPTION - Organic electroluminescent fluorene derivatives of formula (I) are new.    a = substituted azepane moiety of formula (c) or substituted 2,3,6,7-tetrahydro-1H-azepine moiety of formula (d);    R33 = 1-60C alkyl, 6-60C aryl or 3-60C heteroaryl (all optionally substituted by at least one T1);    L1 = substituted 9H-fluorene moiety of formula (e) or substituted indan moiety of formula (f);    A1, B2 = bond, substituted ethene moiety of formula (-C(R21)=C(R22)-) or substituted vinyl-benzene moieties of formulae (g) and (h);    Ar1, Ar2 = 6-60C arylene, 3-60C heteroarylene, 5 or 6 membered heterocycloalkylene containing at least one heteroatom including N, O and S, 3-60C cycloalkylene, 2-60C alkenylene, 2-60C alkynylene, 1-60C alkyleneoxy, 6-60C aryleneoxy or 6-60C arylenethio (all optionally substituted by at least one T1) or bond;    i = 1,2,4,5-tetrayl-phenylene or 3,4,3',4'-tetrayl-biphenylene; either    R1-R20 = H, halo, 1-60C alkyl, 6-60C aryl, 3-60C heteroaryl, 5 or 6 membered heterocycloalkyl containing at least one heteroatom (including N, O or S), 3-60C cycloalkyl, tri(1-60C)alkylsilyl, di(1-60C)alkyl(6-60C)arylsilyl, tri(6-60C)arylsilyl, adamantyl, 7-60C bicycloalkyl, 2-60C alkenyl, 2-60C alkynyl, 1-60C alkoxy, CN, 1-60C alkylamino, 6-60C arylamino, 6-60C ar(1-60C)alkyl, 6-60C aryloxy, 6-60C arylthio, 1-60C alkoxycarbonyl, OH, NO2 or OH; or each of    R1-R20 are linked to an adjacent substituent via 3-60C alkylene or 3-60C alkenylene (optionally with a fused ring) = alicyclic ring, monocyclic or polycyclic aromatic ring;    R21-R26 = 1-60C alkyl, 6-60C aryl, 3-60C heteroaryl, 5 or 6 membered heterocycloalkyl containing at least one heteroatom (including N, O or S), 3-60C cycloalkyl, tri(1-60C)alkylsilyl, di(1-60C)alkyl(6-60C)arylsilyl, tri(6-60C)arylsilyl, adamantyl, 7-60C bicycloalkyl, 2-60C alkenyl, 2-60C alkynyl, 1-60C alkylamino or 6-60C arylamino (all optionally substituted by at least one T1), H, halo, 1-60C alkoxy, CN, (6-60C)ar(1-60C)alkyl, 6-60C aryloxy, 6-60C arylthio, 1-60C alkoxycarbonyl, COOH, NO2 or OH; and    T1 = 1-60C alkyl (optionally substituted with halo), halo, 6-60C aryl, 3-60C heteroaryl (optionally substituted with 6-60C aryl), 5 or 6 membered heterocycloalkyl containing at least one heteroatom including N, O or S, 3-60C cycloalkyl, tri(1-60C)alkylsilyl, di(1-60C)alkyl(6-60C)arylsilyl, tri(6-60C)arylsilyl, adamantyl, 7-60C bicycloalkyl, 2-60C alkenyl, 2-60C alkynyl, 1-60C alkoxy, CN, 1-60C alkylamino, 6-60C arylamino, (6-60C)ar(1-60C)alkyl, 6-60C aryloxy, 6-60C arylthio, 1-60C alkoxycarbonyl, COOH, NO2 or OH.    An INDEPENDENT CLAIM is also included for an organic electroluminescent device comprising a first electrode, second electrode and at least one organic layer interposed between the first and second electrode, where the organic layer comprises (I) and at least one host comprising substituted aryl compounds of formula ((Ar11)a1-X-(Ar12)b1) or ((Ar13)c1-Y1-(Ar14)d1).    X = 6-60C arylene or 4-60C heteroarylene;    Y1 = anthracenylene;    Ar11-Ar14 = 4-60C heteroaryl, 5-60C cycloalkyl or 6-60C aryl (all optionally substituted with at least one 6-60C aryl or 4-60C heteroaryl (both optionally substituted with at least one (halo)1-60C alkyl, 1-60C alkoxy, 3-60C cycloalkyl, halo, CN, tri(1-60C)alkylsilyl, di(1-60C)alkyl(6-60C)arylsilyl or tri(C6-C60)arylsilyl), H, (halo)1-60C alkyl, 1-60C alkoxy, halo, 3-60C cycloalkyl, CN, tri(1-60C)alkylsilyl, di(1-60C)alkyl(6-60C)arylsilyl or tri(6-60C)arylsilyl; and    a1-d1 = 0-4.    DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional view of an organic light emitting diode.    Glass (1)    Transparent electrode (2)    Hole injecting layer (3)    Hole transport layer (4)    Electroluminescent layer (5)