TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Disclosed): 7-(Diphenylamino)-9,9-dimethyl-9H-fluorene-2-carbaldehyde and phosphorus compound of formula (C) are reacted to produce fluorene compound. Preferred Layer: The organic layer comprises arylamine compound and styrylarylamine compound, and further contains organic metals of group 1, group 2, 4-period and 5-period transition metal, lanthanide metal and d-transition element. The organic layer is an electroluminescent layer or a charge generating layer. The mixed region of a reductive dopant and an organic substance or a mixed region of an oxidative dopant and an organic substance is placed on the inner surface of electrode(s). Full Definitions:    Ar=6-60C arylene, 3-60C heteroarylene, 5- or 6-membered heterocycloalkylene containing heteroatom(s) chosen from nitrogen, oxygen and sulfur, 3-60C cycloalkylene, adamantylene, 7-60C bicycloalkylene, 2-60C alkenylene, 2-60C alkynylene, 1-60C alkylenethio, 1-60C alkyleneoxy, 6-60C aryleneoxy, 6-60C arylenethio or group of formula (a), in which arylene, heteroarylene, heterocycloalkylene, cycloalkylene, adamantylene, bicycloalkylene, alkenylene, alkylenethio, alkyleneoxy, aryleneoxy or arylenethio are optionally substituted by substituent (S);    A,B'=single bond, -(CR11)(R12)m-, -N(R13)-, -S-, -O-, -Si(R14)(R15)-, -P(R16)-, -C(=O)-, -B(R17)-, -In(R18)-, -Se-, -Ge(R19)(R20)-, -Sn(R21)(R22)-, -Ga(R23)- or -(R24)C=C(R25)-;    R1-R8,R11-R25=H, deuterium, halo, 1-60C alkyl, 6-60C aryl, 3-60C heteroaryl containing heteroatom(s) chosen from nitrogen, oxygen and sulfur, morpholino, thiomorpholino, 5- or 6-membered heterocycloalkyl containing heteroatom(s) chosen from nitrogen, oxygen and sulfur, 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, cyano, 1-60C alkylamino, 6-60C arylamino, 1-60C alkyloxy, 1-60C alkylthio, 6-60C aryloxy, 6-60C arylthio, 1-60C alkoxycarbonyl, 1-60C alkylcarbonyl, 6-60C arylcarbonyl, carboxyl, nitro or hydroxyl, in which alkyl, aryl, heteroaryl, heterocycloalkyl, cycloalkyl, trialkylsilyl, dialkylarylsilyl, triarylsilyl, adamantyl, bicycloalkyl, alkenyl, aralkyl, alkyloxy, alkylthio, aryloxy, arylthio, alkylamino, arylamino, alkoxycarbonyl, alkylcarbonyl or arylcarbonyl of R1-R8 and R11-R25 are optionally substituted by substituent (S);    R1+R2, R3+R4, R5+R6, R7+R8 + 3-60C alkylene or 3-60C alkenylene=alicyclic ring or mono- or polycyclic aromatic ring;    substituent (S)=deuterium, halo, 1-60C alkyl with or without halogen substituent(s), 6-60C aryl, 3-60C heteroaryl containing heteroatom(s) chosen from nitrogen, oxygen and sulfur with or without 6-60C aryl substituent(s), morpholino, thiomorpholino, 5- or 6-membered heterocycloalkyl containing heteroatom(s) chosen from nitrogen, oxygen and sulfur, 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, cyano, 1-60C alkylamino, 6-60C arylamino, 1-60C alkyloxy, 1-60C alkylthio, 6-60C aryloxy, 6-60C arylthio, 1-60C alkoxycarbonyl, 1-60C alkylcarbonyl, 6-60C arylcarbonyl, carboxyl, nitro or hydroxyl;and    m=1-3.    Preferred Definitions:    Ar=43 groups, such as group of formula (b);and    R31-R42=R1.    SPECIFIC COMPOUNDS - 719 Fluorene-containing organic electroluminescent compounds such as 7-((E)-2-(4-((E)-2-(7-(diphenylamino)-9,9-dimethyl-9H-fluoren-2-yl)ethenyl)phenyl)ethenyl)-9,9-dimethyl-N,N-diphenyl-9H-fluoren-2-amine of formula (I), 7-((E)-2-(4-((E)-2-(7-(bis(naphthalen-2-yl)amino)-9,9-dimethyl-9H-fluoren-2-yl)ethenyl)phenyl)ethenyl)-9,9-dimethyl-N,N-bis(naphthalen-2-yl)-9H-fluoren-2-amine, 7-((E)-2-(4-((E)-2-(9,9-dimethyl-7-(naphthalen-1-yl(1H-naphthalen-4-yl)amino)-9H-fluoren-2-yl)ethenyl)phenyl)ethenyl)-9,9-dimethyl-N,N-bis(naphthalen-1-yl)-9H-fluoren-2-amine, 7-((E)-2-(4-((E)-2-(9,9-dimethyl-7-((5-methylcyclohexa-1,3-dien-1-yl)(3-methylcyclohexa-1,5-dien-1-yl)amino)-9H-fluoren-2-yl)ethenyl)phenyl)ethenyl)-9,9-dimethyl-N-(5-methylcyclohexa-1,3-dien-1-yl)-N-(3-methylphenyl)-9H-fluoren-2-amine and 7-((E)-2-(4-((E)-2-(9,9-dimethyl-7-((4-methylcyclohexa-1,3-dien-1-yl)(4-methylcyclohexa-1,5-dien-1-yl)amino)-9H-fluoren-2-yl)ethenyl)phenyl)ethenyl)-9,9-dimethyl-N-(4-methylcyclohexa-1,3-dien-1-yl)-N-(4-methylphenyl)-9H-fluoren-2-amine are disclosed.    EXAMPLE - A phosphorus compound (C) (in g) (5.1) and 7-(Diphenylamino)-9,9-dimethyl-9H-fluorene-2-carbaldehyde (5.8) were added to a reactor and dried under reduced pressure. Tetrahydrofuran (200 ml) was added under nitrogen atmosphere, and mixture was stirred. Potassium t-butoxide (4.14) dissolved in tetrahydrofuran (30 ml) was slowly added, and heated. Water (500 ml) was added, filtered and washed to produce fluorene-containing organic electroluminescent compound. The compound provided electroluminescent device having luminous efficiency of 12.8 cd/A.