Fluorene-containing polymers and electroluminescent devices therefrom

An article comprising (a) a transparent substrate having on one surface a transparent or semi-transparent conducting layer, (b) a film comprising a copolymer comprising 10-90 percent by weight of groups of Formula (I):

• and from 10-90 percent by weight of groups selected from Formulas (II), (III), and (IV):
• and mixtures thereof wherein R1 is independently in each occurrence H, C1-C20 hydrocarbyl or C1-C20 hydrocarbyl containing one or more S, N, O, P or Si atoms, C4-C16 hydrocarbyl carbonyloxy, C4-C16 aryl(trialkylsiloxy) or both R1 may form with the 9-carbon on the fluorene ring a C5-C20 cycloaliphatic structure or a C4-C20 cycloaliphatic structure containing one or more heteroatoms of S, N, or O;
• R2 is independently in each occurrence C1-C20 hydrocarbyl, C1-C20 hydrocarbyloxy, C1-C20 thioether, C1-C20 hydrocarbylcarbonyloxy or cyano;
• R3 is independently in each occurrence carboxyl, C1-C20 alkyl, C1-C20 alkoxy or a group of the formula —CO2R4 wherein R4 is a C1-C20 alkyl;
• a and b are independently in each occurrence 0 or an integer from 0 to 3 and
• (c) a metallic electrode, wherein the film is located between the transparent or semi-transparent conducting layer and the metallic electrode.