Strongly Conjugated Hydroporphyrin Dyads: Extensive Modification of Hydroporphyrins鈥?Properties by Expanding the Conjugated System
详细信息 查看全文
- 作者：Zhanqian Yu ; Chirag Pancholi ; Ganga Viswanathan Bhagavathy ; Hyun Suk Kang ; Jamie K. Nguyen ; Marcin Ptaszek
- 刊名：Journal of Organic Chemistry
- 出版年：2014
- 出版时间：September 5, 2014
- 年：2014
- 卷：79
- 期：17
- 页码：7910-7925
- 全文大小：735K
- ISSN：1520-6904
文摘
We report the synthesis and basic photophysical characterization of strongly conjugated hydroporphyrin (chlorin and bacteriochlorin) dyads. Hydroporphyrins are connected at their respective 13 (尾) or 15 (meso) positions by ethynyl or butadiynyl linkers. Synthesis entails a series of palladium-catalyzed reactions, starting from appropriate bromobacteriochlorin or bromochlorin. Strong conjugation in the dyads results in a significant bathochromic shift of longest-wavelength (Qy-like) band, which in case of the 13鈥?3鈥?ethynyl-linked bacteriochlorin dyad is positioned past 800 nm. The Qy-like band is broad and split for the 13鈥?3鈥?linked chlorin and bacteriochlorin dyads. All dyads exhibit an intense, relatively narrow fluorescence emission band in nonpolar solvents. Bacteriochlorin dyads exhibit a strong dependence of fluorescence intensity on the solvent polarity, which results in more than 10-fold quenching of fluorescence in dimethylformamide. The assembling of hydroporphyrins into strongly conjugated arrays represents an efficient means to tune and expand their optical and photochemical properties, which should greatly broaden the properties attainable for these chromophores.