Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 120-749, Korea.
J Phys Chem B. 2010 Nov 18;114(45):14528-36. doi: 10.1021/jp1022696. Epub 2010 May 10.
meso-β doubly linked Zn(II) porphyrin arrays and their indene-fused analogues were prepared by Suzuki-Miyaura coupling and subsequent oxidation with DDQ-Sc(OTf)(3). The excited state properties of these conjugated porphyrin arrays have been investigated by steady-state and time-resolved spectroscopy along with quantum mechanical calculations to reveal their molecular shape dependencies with respect to syn- versus anti-connectivity as well as nonfused versus fused structures. Nonfused syn-trimer exhibits nearly the same S(1)-state lifetime and two-photon absorption (TPA) value as the nonfused dimer, while the nonfused anti-trimer exhibits different values. The TD-DFT calculations also demonstrate that the nonfused anti-trimer has a different electronic structure from the corresponding syn-trimer. Indene-fused dimers and trimers exhibit the enhanced TPA values and shortened S(1)-state lifetime because of the elongated π-conjugation and the perturbation of electronic structures. Our research provides further insight into the molecular-shape-dependent electronic properties of meso-β doubly linked Zn(II) porphyrin arrays.
介孔-β 双连接锌（II）卟啉阵列及其茚并融合类似物通过 Suzuki-Miyaura 偶联和随后用 DDQ-Sc(OTf)(3)氧化来制备。通过稳态和时间分辨光谱以及量子力学计算研究了这些共轭卟啉阵列的激发态性质，以揭示它们的分子形状依赖性，包括顺式与反式连接以及非融合与融合结构。非融合的 syn-trimer 表现出与非融合二聚体几乎相同的 S(1)态寿命和双光子吸收 (TPA) 值，而非融合的 anti-trimer 则表现出不同的值。TD-DFT 计算还表明，非融合的 anti-trimer 具有与相应 syn-trimer 不同的电子结构。由于 π 共轭的延长和电子结构的干扰，茚并融合的二聚体和三聚体表现出增强的 TPA 值和缩短的 S(1)态寿命。我们的研究为介孔-β 双连接锌（II）卟啉阵列的分子形状依赖性电子性质提供了进一步的见解。
