POLYMERIC MATERIAL COMPRISING N, P, S, AS OR SE AND COMPOSITION FOR CHARGE TRANSPORT MATERIAL

There is described a polymeric material comprising at least one repeat unit, the or each (if more than one) repeat unit consisting substantially of a moiety of Formula (1) in which: Y1 represents, independently if in different repeat units, N, P, S, As and/or Se, preferabl y is N; Ar1 and Ar2 which may be the same or different, represent, independent ly if in different repeat units, a multivalent (preferably bivalent) aromatic group (preferably mononuclear but optionally polynuclear) optionally substituted by at least one optionally substituted C1-40carbyl-derived groups and/or at least one other optional substituent, a nd Ar3 represents, independently if in different repeat units, a mono or multivalent (preferably bivalent) aromatic group (preferably mononuclear but optionally polynuclear) optionally substituted by at least one: optionally substituted C1-40carbyl-derived group and/or at lea st one other optional substituent; where at least one terminal group is attached in the polymer to the Ar1, Ar2 and optionally Ar3 groups located at the end of the polymer chains, so as to cap the polymer chains and prevent further polymer growth, and at least one terminal group is derived from at least one end capping reagent used in the polymerisation to form said polymeric material to control the molecul ar weight thereof. A charge transport material comprising such polymers is of use in (amongst other things) electroreprographic device s and electroluminescent devices. A method of making these polymers by controlling their molecular weight with an end capping reagent i s also described.