Energy Levels of Oligothiophenes in the Higher Excited Triplet States
Energy Levels of Oligothiophenes in the Higher Excited Triplet States
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DOI：
10.1021/jp065714w
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发表时间：
2007
影响因子：
3.7
通讯作者：
Yosuke Oseki;M. Fujitsuka;M. Sakamoto;and Xichen Cai;T. Majima
中科院分区：
文献类型：
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作者：
Yosuke Oseki;M. Fujitsuka;M. Sakamoto;and Xichen Cai;T. Majima
低聚噻吩的能级（nT：二聚体（2 T）、三聚体（3 T）、四聚体（4 T）和五聚体（5 T（Tn，n ≥ 2）是通过使用纳秒-纳秒双色双激光闪光光解从Tn态的nT（nT（Tn））到能量猝灭剂的三重态能量转移（泰特）估计的，其中，在第二激光照射期间，利用第一激光闪光产生的最低三重激发态（nT（T1））中的nT被激发到nT（Tn）。溶液中的3 T（Tn）、4 T（Tn）和5 T（Tn）的能级（E（Tn））实验估计分别为3.4 ± 0.1、3.3 ± 0.1和3.2 ± 0.1eV，并且估计的能量被分配给第二三重激发态（T2）的能量。E（T2）随着噻吩环数目的增加而逐渐减小，表明即使在较高激发态和nT（T1）中，nT中的三重激发态也相对局部化。还观察到Tm（m ≥ 3）态的泰特。
Energy levels of oligothiophenes (nT: dimer (2T), trimer (3T), tetramer (4T), and pentamer (5T)) in the higher triplet excited state (Tn, n ≥ 2) were estimated from triplet energy transfer (TET) from nT in the Tn state (nT(Tn)) to energy quencher by using the nanosecond−nanosecond two-color two-laser flash photolysis, in which nT in the lowest triplet excited state (nT(T1)) generated with the first laser flash was excited to nT(Tn) during the second laser irradiation. The energy levels (E(Tn)) of 3T(Tn), 4T(Tn), and 5T(Tn) in solution were experimentally estimated to be 3.4 ± 0.1, 3.3 ± 0.1, and 3.2 ± 0.1 eV, respectively, and the estimated energies are assigned to those of the second triplet excited state (T2). The E(T2) was gradually decreased with increasing the number of thiophene rings, suggesting that the triplet exited state in nT is relatively localized even in the higher excited state as well as nT(T1). The TET from the Tm (m ≥ 3) state was also observed.