Takayuki Iijima

Synthesis and reactivity of Al(Et)q'2 (q' = 2-methyl-8-quinolinolato) and crystal structures of [Al(Et)2q]2 and Alq'2q (q = 8-quinolinolato)

Abstract A crystal structure of a dimeric aluminum complex ([Al(Et)2(q)]2, q=8-quinolinolato) (1) obtained by reaction of AlEt3 with 8-quinolinol has been determined by X-ray crystallography. Reaction of AlEt3 with 2-methyl-8-quinolinol gave a new reactive complex ( Al ( Et ) q ′ 2 (q′=2-methyl-8-qinolinolato) (2)) in good yield. Reaction of 2 with 8-quinolinol provided Alq′2q (3) and the crystal structure of 3 was determined.

Quadrimolecular recombination kinetics of photogenerated charge carriers in the composites of regioregular polythiophene derivatives and soluble fullerene

Light-induced electron spin resonance (LESR) measurements have been performed on the composites of regioregular polythiophene derivatives and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) in order to study the recombination kinetics of photogenerated charge carriers. We adopt two regioregular polymers with different side chains; head-to-tail poly(3-hexylthiophene) (RR-P3HT) and head-to-head poly(3-dodecynylthiophene-2,5-diyl) [HH-P3(C≡CDec)Th]. In both systems, two LESR signals due to positive polarons on the polymer (g∼2.002) and fullerene radical anions (g∼2.000) have been observed. Quadrimolecular recombination (QR) kinetics, previously reported for RR-P3HT/C60 composites, where two positive polarons and two radical anions recombine simultaneously, has been confirmed in both systems by the observation of Iex0.25 dependence of the LESR intensity on the excitation light intensity (Iex) and the decay curve of the LESR intensity. This process implies the formation of doubly-charged states such as bipol...