TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The electroluminescent device comprises fluorene derivatives of formulae (II)-(VI). The fluorene derivatives (I)-(VI) is a monoamine compound. The fluorene derivatives (I)-(VI) is used as a hole transport material in a hole-transport or hole injection layer, an exciton-blocking material, an electron blocking material and a matrix material in an emitting layer in the device. The fluorene derivative is of formula (VIII). Preferred Definitions:    B1 = phenylene, biphenylene, terphenylene, naphthylene, pyridinylene, pyrimidinylene, pyrazinylene, pyridazinylene, triazinylene, dibenzo-furanylene, dibenzothiophenylene fluorenylene, carbazoylene, which are reapectively substituted with R6, or single bond; and    Ar1, Ar2 = phenyl-pyridyl, phenyl naphthyl, biphenyl, terphenyl or quarterphenyl, which are respectively substituted with at least one R6.    SPECIFIC COMPOUNDS - Use of 23 compounds is disclosed, e.g. N-(biphenyl-2-yl)-N-(biphenyl-4-yl)-9-methyl-9-p-tolyl-9H-fluoren-2-amine (Ia), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9-p-tolyl-9H-fluoren-2-amine, N-(biphenyl-4-yl)-N-(9-phenyl-9-p-tolyl-9H-fluoren-2-yl)dibenzo(b,d)furan-4-amine, N-(4-(dibenzo(b,d)thiophen-2-yl)phenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9-isopropyl-9-p-tolyl-9H-fluoren-2-amine and N-(biphenyl-4-yl)-N-(4-(dibenzo(b,d)furan-3-yl)phenyl)-9-isopropyl-9-p-tolyl-9H-fluoren-2-amine.    EXAMPLE - 27.6 g Biphenyl-2-yl-biphenyl-4-yl-amine and 30 g 2-bromo-fluorene were dissolved in 500 ml toluene. The solution was degassed and saturated with nitrogen. 4.3 ml Tri-tert-butylphosphine-1 M solution and 0.48 g palladium(II) acetate were added. Subsequently 20.6 g sodium-tert-butoxide was added. The reaction mixture was heated for 5 hours under an inert atmosphere. The mixture was distributed in the connection between toluene and water. The organic phase was washed three times with water, dried over sodium sulfate and evaporated. The crude product was filtered on silica gel with toluene, and the residue was recrystallized to obtain (Ia).