Electronic Structures of Organosilicon Polymers Containing Thienylene Units

The electronic structures of simplified poly(disilanylene(thienylene)_n) (n = 1-5) have been studied in detail on the basis of the one-dimensional tight-binding self-consistent fieldcrystal orbital method. The result suggests that the sp³-hybridized orbital of silicon atoms almost cuts off the π-conjugation occurring from the thienylene units. The π-π* interband transition energy becomes smaller with an increase of n (number of thiophene rings), while the σ-σ* one shows almost no change. Electronic structures of poly(ethylene(thienylene)_n) (n = 1-3), poly(silylene(thienylene)_n) (n = 1), and polythiophene have also been examined for comparison.