REGIOCHEMISTRY AND CONFORMATION OF POLY(3-HEXYLTHIOPHENE) VIA THE SYNTHESIS AND THE SPECTROSCOPIC CHARACTERIZATION OF THE MODEL CONFIGURATIONAL TRIADS

The four model configurational triads of poly(3-hexylthiophene) (PHT) were synthesized by cross-coupling of the appropriate stannyl and brom o 3-hexylthiophene derivatives, catalyzed by Pd[(C6H5)3P]4. The compar ison of H-1 and C-13 NMR chemical shifts of the triads with those of P HT allows the unambiguous assignment of the regiochemistry of the poly mer. The NMR data of the triads, in conjunction with the results of fo rce field MMP2 calculations, also give information on the conformation al properties of PHT samples of different regiochemistry.