Five kinds of polythiophenes bearing a crown ethereal subunit directly bonded to the thiophene ring have been prepared by the following organometallic polycondensation : ii) nX-Ar-X + nNi(0)L(m) --> (Ar-)(n); (ii) aX-Ar-X + bX-Ar’-X + (a + b)(NiLm)-L-0 --> Ar-a(Ar-’)(b), and (iii) nX-Ar-X + nMe(3)-Sn-Ar’-SnMe3 --> (Ar-Ar-’)(n) (Pd-catalyzed); Ar = thiophene-2,5-diyl with the crown ethereal subunit, Polythiophenes with alkoxy substituents (OCH3 and O(CH2)(2)OCH3) are also prepared by the organometallic polycondensation. The crown ethereal polymers exhibit photoluminescence in a range of 467-603 nm in both CHCl3 solutions and films. Their electroluminescence spectra essentially agree with the photoluminescence spectra. The crown ethereal polythiophenes have st high affinity toward Na+. After chemical oxidation (or p-doping) and reduction (or n-doping), the polymers shaw an electrical conductivity of 5.4 x 10(-7) to 1.8 S cm(-1). The Na-doped and electrically conducting state of crown ethereal polythiophenes shows some stability under air, which is attributed to the strong affinity of the polymer to Na+. Cyclic voltammetry of the crown and linear ethereal polythiophenes reveals a large difference (about 2 Tri between n-doping and n-undoping potentials.