NOVELTY - Polymer compounds (I) are new.    USE - (I) are useful: as an organic semiconductor layer or component; in an electronic or electro-optical device including an organic field effect transistor, thin film transistor, integrated circuit, radio frequency identification tag, photodetector, sensor, logic circuit, memory element, capacitor, organic photovoltaic cell, charge injection layer, charge transport layer or interlayer in polymer light emitting diodes, Schottky diode, planarizing layer, antistatic film, polymer electrolyte membrane, conducting substrate or pattern, photoconductor, electrophotographic element or organic light emitting diode (all claimed); and as a polymer electrolyte membranes in fuel cells.    ADVANTAGE - (I) provides electronic or electro-optical device, which exhibits improved short-circuit currents and higher fill factors, is easy to synthesize, and exhibits high charge mobility, good processability and oxidative stability.    DETAILED DESCRIPTION - Polymer compounds of formula (I) are new.    R1 = 1-40C carbyl, 1-40C hydrocarbyl (both optionally substituted and optionally comprises at least one heteroatom), silyl (optionally substituted), H, halo, aryl, heteroaryl, -CN, -NC, -NCO, -NCS, -OCN, -SCN, -C(=O)NR1aR1b, -C(=O)X1, -C(=O)R1a, -C(OR1a)2R1b, -NH2, -NR1aR1b, -SH, -SR1a, -SO3H, -SO2R1a, -OH, -NO2, -CF3 or -SF5;    R2, R3 = R1, -CH2Cl, -CHO, -CH=CH2, CCH, -SiR1aR1bR1c, -SnR1aR1bR1c, -BR1aR1b, -B(OR1a)(OR1b), -B(OH)2, -OSO2R1a-, -C(R1a)=CR1aR1b, -SiR1aR1bX1, -SiR1a(X1)2 or -Si(X1)3;    L1 = single bond, -C(=O)-, imine, hemiacetal or acetal;    X1 = halo; either    R1a, R1b and R1c = 1-20C aliphatic hydrocarbyl, aromatic 1-20C hydrocarbyl (both optionally substituted) or H; or    R1aR1b = ring;    w, y = greater than or equal to 0;    x, n = greater than or equal to 1;    Ar1-Ar3 = mono- or poly-nuclear aryl or mono- or poly-nuclear heteroaryl (both optionally substituted);    Ar4 = CY1=CY2, -CC-, (-(Ar5-N(Ar5)-Ar5)m-) or Ar1;    m = 1-3;    Ar5 = Ar1; and    Y1, Y2 = H, halo or -CN.    INDEPENDENT CLAIMS are also included for:    (1) a polymer comprising at least one of a monomer repeating unit of formula (III), and optionally at least one of hydrocarbyl of formula (-Ar4-) (II);    (2) converting (I) to aldehyde or ketone polymer comprising providing (I) (where L1 is an imine, a hemiacetal or an acetal), and cleaving the imine, hemiacetal or acetal;    (3) preparing (I); and    (4) a copolymer comprising two different types of unit, one of which is (I), and the other is a unit having hole or electron transporting properties.