Design of Triads for Probing the Direct Through Space Energy Transfers in Closely Spaced Assemblies

详细信息    查看全文

• 作者：Jean-Michel Camus ; Shawkat M. Aly ; Daniel Fortin ; Roger Guilard ; Pierre D. Harvey
• 刊名：Inorganic Chemistry
• 出版年：2013
• 出版时间：August 5, 2013
• 年：2013
• 卷：52
• 期：15
• 页码：8360-8368
• 全文大小：480K
• 年卷期：v.52,no.15(August 5, 2013)
• ISSN：1520-510X

文摘

Using a selective stepwise Suzuki cross-coupling reaction, two trimers built on three different chromophores were prepared. These trimers exhibit a DA₁-A₂ structure where the donor D (octa-尾-alkyl zinc(II)porphyrin either as diethylhexamethyl, 10a, or tetraethyltetramethyl, 10b, derivatives) through space transfers the S₁ energy to two different acceptors, di(4-ethylbenzene) zinc(II)porphyrin (A₁; acceptor 1) placed cofacial with D, and the corresponding free base (A₂; acceptor 2), which is meso鈥搈eso-linked with A₁. This structure design allows for the possibility of comparing two series of assemblies, 9a,b (DA₁) with 10a,b (DÂ₁-A₂), for the evaluation of the S₁ energy transfer for the global process D*鈫?b>A₂ in the trimers. From the comparison of the decays of the fluorescence of D, the rates for through space energy transfer, k_ET for 10a,b (k_ET 鈮?6.4 脳 10⁹ (10a), 5.9 脳 10⁹ s^鈥? (10b)), and those for the corresponding cofacial DA₁ systems, 9a,b, (k_ET 鈮?5.0 脳 10⁹ (9a), 4.7 脳 10⁹ s^鈥? (9b)), provide an estimate for k_ET for the direct through space D*鈫?b>A₂ process (i.e., k_ET(DA₁-A₂) 鈥?k_ET(DA₁) = k_ET(D*鈫?b>A₂) 1 脳 10⁹ s^鈥?). This channel of relaxation represents 15% of k_ET for D*鈫?b>A₁.