▎ 摘　　要

NOVELTY - Oligophenylene monomers, are new. USE - The oligophenylene monomers are useful for synthesizing polymeric precursors for preparing graphene nanoribbons (claimed). ADVANTAGE - By using oligophenylene monomers, for an AA-type polymerization system, only one bifunctionalized component is needed. For this reason, the precise weighing of two components is circumvented. Thus, this will result in higher molecular weights and an increase of graphene nanoribbon length. DETAILED DESCRIPTION - Oligophenylene monomers of general formulae A, B, C, D, E and F, are new. Ar=selected from e.g. biphenyl groups of formulae 1-5; X or Y=halogene, trifluoromethylsulfonate or diazonium; R1, R2, and R3=independently of each other H, halogene, -OH, -NH2, -CN, -NO2, a linear or branched, saturated or unsaturated 1-40C hydrocarbon residue, which can be substituted 1- to 5-fold with halogene (F, Cl, Br, or I), -OH, -NH2, -CN and/or -NO2, and where one or more CH2-groups can be replaced by -O-, -S-, -C(O)O-, -O-C(O)-, -C(O)-, -NH- or -NR-; and R=an optionally substituted 1-40C hydrocarbon residue, or an optionally substituted aryl, alkylaryl or alkoxyaryl residue. INDEPENDENT CLAIMS are: (1) a polymeric precursor for preparing graphene nanoribbons obtainable from monomers; (2) graphene nanoribbons, obtainable by cyclodehydrogenation of polymeric precursors; (3) a process for preparing oligophenylene monomers of general formula I or II; (4) a process for preparing monomers of the general formula IIIa comprising Diels-Alder reaction of tetraphenylcyclopentadienone; (5) a process for preparing monomers of the general formula IIIb comprising Diels-Alder reaction of tetraphenylcyclopentadienone; (6) a process for preparing monomers of the general formula IVa comprising Diels-Alder reaction of biphenyl compound and tetraphenylcyclopentadienone; and (7) a process for preparing monomers of the general formula IVb comprising Diels-Alder reaction of biphenyl compound and tetraphenylcyclopentadienone. R1, R2, and R3=independently of each other H, halogene, -OH, -NH2, -CN, -NO2, a linear or branched, saturated or unsaturated 1-40C hydrocarbon residue, which can be substituted 1- to 5-fold with halogene (F, Cl, Br, or I), -OH, -NH2, -CN and/or -NO2, and where one or more CH2-groups can be replaced by -O-, -S-, -C(O)O-, -O-C(O)-, -C(O)-, -NH- or -NR-; R=an optionally substituted 1-40C hydrocarbon residue, or an optionally substituted aryl, alkylaryl or alkoxyaryl residue; and X=halogene, trifluoromethylsulfonate or diazonium. Where X=halogene and Y=H, or X=H and Y=halogene, provided that R3=H if X=H and Y=halogene.