TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Claimed): Preparation of (I) comprises coupling deuterated groups Y1 with the central groups Z by one or more metal organic coupling reactions. Preferred Components: The emitter compound is: a fluorescent dopant, which is (hetero)aromatic ring system having 5-60 ring atoms that is optionally substituted with one or more R3; or a phosphorescent dopant, which is a compound containing organo metallic complex having at least one metal-carbon bond containing a metal, which is iridium or platinum (both preferred), chromium, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, nickel, platinum, copper, silver or gold. The emitter compound contains one or more deuterium atoms. The emitter compound contains one or more phenyl-, tolyl-, biphenyl-, terphenyl-, diphenyltriazinyl-, naphthyl-, pyridinyl- or methyl-groups, which are completely substituted with deuterium atoms.Either R3=H, D, F, Cl, Br, I, CN, N(R4) 2, N(Ar1) 2, NO 2, Si(R4) 3or linear 1-40C-alkyl or -(thio)alkoxy or 2-40C-alkenyl or -alkynyl or branched or cyclic 3-40C-alkyl or -(thio)alkoxy (all optionally substituted with one or more R4, and where one or more adjacent or non-adjacent CH 2-groups are optionally replaced by -C?=C-, -R4C=CR4-, Si(R4) 2, C=O, C=S, C=Se, C=NR4, P(=O)(R4), SO, SO 2, NR4, O, S, COO or CONR4), or (hetero)aromatic ring system having 5-60 ring atoms, which is optionally substituted with one or more R4; ortwo or more R3 bonded together=mono- or polycyclic aliphatic or (hetero)aromatic ring system; eitherR4=H, D or aliphatic or (hetero)aromatic 1-20C-organic residue, in which one or more H atoms are optionally replaced by D or F; ortwo or more R4 bonded together=mono- or polycyclic aliphatic or (hetero)aromatic ring system; andAr1=6-60C-aryl (optionally substituted with one or more R4). Preferred Definitions:    Y1=phenyl-, tolyl-, biphenyl-, terphenyl-, diphenyltriazinyl-, naphthyl-, pyridinyl or methyl, where Y1 contains two or more deuterium atoms and no further substituents other than hydrogen and deuterium; and    Z=terphenyl, diphenyltriazine, tetraphenylene, triphenylamine, pyridine-biphenyl, phenylbipyridine, N-phenylcarbazole, benzophenanthrene, pyrene, benzopyrene, pentacene, benzanthracene, naphthacene, chrysene, triphenylene, dibenzochrysene, perylene, spirobidibenzosilol, spirobifluorene, spirofluoreneanthrone, spirofluoreneacridane, spirofluorenedibenzocycloheptatriene, indenofluorene, benzocarbazole, dibenzocarbazole, diindenofluorene, benzindenofluorene, dibenzindenofluorene, benzophenanthroline, benzacridine, benzacridone, fluoranthene, benzofluoranthene, benzophenanthridine, benzophenazine, benzonaphthofuran, benzonaphthothiophene, acephenanthrylene, quinacridone, benzofluoranthene, benzimidazole quinazoline, dibenzoquinoline, dibenzoquinoxaline, dibenzoisoindole, dibenzocinnoline, dibenzophthalazine, dibenzoquinazoline, naphthoquinoline, aceanthrylene, indolocarbazole, indenocarbazole, phenanthrocarbazole, phenanthrimidazole, benzocarboline, anthroxazole, phenanthroxazole, pyrenyltriazine, dibenzazepine, truxene, truxenone or sumanene (all optionally substituted with one or more R).    SPECIFIC COMPOUNDS - 1626 Compounds (I) are disclosed e.g. 2-diperdeuterophenyltriazenyl-9,9'-spirobifluorene of formula (Ia), 7-(trideuteriomethyl)benzo(a)anthracene, 7-(2,3,4,5,6-pentadeuteriophenyl)benzo(a)anthracene, 7-(2,3,5,6-tetradeuterio-4-(2,3,4,5,6-pentadeuteriophenyl)phenyl)benzo(a)anthracene and 5-(trideuteriomethyl)benzo(a)anthracene.    EXAMPLE - d5-Diphenylchlorotriazine (93%, 313 mmole) and spiro-2-boronic acid (95%, 406.9 mmole) were mixed with sodium carbonate (338.9 mmole) in toluene/dioxane/water (2100 ml, 3:3:1) and degassed in the apparatus for 60 minutes by introduction of an inert gas into the reaction solution. Then paladiumtetrakistriphenylphosphine (6.3 mmole) was added and heated for 5 hours under reflux. After completion of the reaction, the phases were separated and the organic phase was washed, dried with sodium sulfate and concentrated. The precipitated solid was extracted and worked up to give 2-diperdeuterophenyltriazenyl-9,9'-spirobifluorene.