Broad-Band N鈭?/sup>N Pt(II) Bisacetylide Visible Light Harvesting Complex with Heteroleptic Bodipy Acetylide Ligands

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• 作者：Fangfang Zhong ; Ahmet Karatay ; Liang Zhao ; Jianzhang Zhao ; Cheng He ; Caishun Zhang ; Halime Gul Yaglioglu ; Ayhan Elmali ; Bet眉l K眉莽眉k枚z ; Mustafa Hayvali
• 刊名：Inorganic Chemistry
• 出版年：2015
• 出版时间：August 17, 2015
• 年：2015
• 卷：54
• 期：16
• 页码：7803-7817
• 全文大小：1005K
• ISSN：1520-510X

文摘

Pt(II) dbbpy bisacetylide (dbbpy = 4,4鈥?di(tert-butyl)-2,2鈥?bipyridine) complex (Pt-1) with two different Bodipy ligands was prepared with the goal to attain broad-band visible light absorbing, efficient funneling of the photoexcitation energy (via resonance energy transfer, RET) to the energy acceptor and high triplet formation quantum yields. Construction of the above-mentioned molecular structural motif is challenging because two different arylacetylide ligands are incorporated in the complex; normally two homoleptic acetylide ligands were used for this kind of N^{鈭?/sup>N Pt(II) complexes. A reference complex with trans bis(tributylphosphine) Pt(II) bisacetylide protocol (Pt-4) was prepared for comparison of the photophysical properties. The two different Bodipy ligands in Pt-1 and Pt-4 constitute singlet/triplet energy donor/acceptor, as a result the harvested photoexcitation energy can be funneled to the triplet state confined on one of the two Bodipy ligands. The photophysical properties of the complexes were studied with steady state UV鈥搗is absorption and luminescence spectroscopies, femto- and nanosecond transient absorption spectroscopies, cyclic voltammetry, as well as DFT/TDDFT calculations. Fluorescence/phosphorescence dual emission were observed for the complex. The ultrafast intramolecular singlet/triplet energy transfer in Pt-1 was confirmed by the transient absorption spectroscopy (k_FRET = 2.6 脳 1011 s鈥?, 桅_FRET = 87.1%) followed by an intersystem crossing (k_ISC = 1.9 脳 1010 s鈥?), and the triplet state lifetime (蟿_T) is 54.1 渭s. The reference complex Pt-4 shows drastically different kinetics with k_FRET = 6.9 脳 1010 s鈥?, 桅_FRET = 81.0%, k_ISC = 5.83 脳 109 s鈥?, and 蟿_T = 147.9 渭s. Different singlet oxygen (1O₂) quantum yields (桅_螖 = 75% and 70%) and triplet state quantum yields (桅_T = 91% and 69%, respectively) were observed for complexes Pt-1 and Pt-4.}