stand the different photoluminescence properties of these D-Si-A polymers.A mixture of 4,7-dibromo-2,1,3-benzothiadiazole (88 mg, 0.30 mmol), 5"-n-hexyl-5-di-n-hexyl(5-tri-n-buthylstannyl-2-thienyl)silyl-2,2':5',2"-terthiophene (0.55 g, 0.61 mmol), [PdA C H T U N G T R E N N U N G (PPh 3 ) 2 Cl 2 ] (11 mg, 0.015 mmol) and THF (5 mL) was heated to reflux overnight and the resulting precipitates were filtered through a celite pad. After the usual workup, the residue was subjected to silica gel column chromatography eluting with nhexane/ethyl acetate = 15:1, and the fraction containing M2 was further treated with preparative GPC eluting with toluene to give 0.29 g (70 % yield) of M2 as a dark-brown liquid: 1 H NMR (CDCl 3 ): d = 0.86-0.91 (m, 18 H, Hex), 1.14-1.17 (m, 8 H, Hex), 1.27-1.52 (m, 44 H, Hex), 1.68 (quint, 4 H, J = 7.5 Hz, Hex), 2.79 (t, 4 H, J = 7.5 Hz, Hex), 6.68 (d, 2 H, J = 3.5 Hz, thiophene), 6.98 (d, 2 H, J = 3.5 Hz, thiophene), 6.99 (d, 2 H, J = 3.5 Hz, thiophene), 7.09 (d, 2 H, J = 3.5 Hz, thiophene), 7.25 (d, 2 H, J = 3.5 Hz, thiophene), 7.26 (d, 2 H, J = 3.5 Hz, thiophene), 7.43 (d, 2 H, J = 3.5 Hz, thiophene), 7.91 (s, 2 H, phenylene), 8.23 ppm (d, 2 H, J = 3.5 Hz, thiophene); 13 C NMR (CDCl 3 ): d =