共查询到20条相似文献,搜索用时 0 毫秒
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Qingshan Hao Dr. Yi Zeng Dr. Tianjun Yu Dr. Jinping Chen Prof. Dr. Guoqiang Yang Prof. Dr. Yi Li 《化学:亚洲杂志》2013,8(5):1015-1022
A series of doubly β‐to‐β bridged cyclic ZnII porphyrin arrays were prepared by a stepwise Suzuki–Miyaura coupling reaction of borylated ZnII porphyrin with different bridge groups. The coupling of the building block of β,β′‐diboryl ZnII porphyrin 1 with different bridges provided the doubly β‐to‐β carbazole‐bridged ZnII porphyrin array 3 , the fluorene‐bridged ZnII porphyrin array 5 , the fluorenone‐bridged ZnII porphyrin array 7 , and the three‐carbazole‐bridged ZnII porphyrin ring 8 . The structural assignment of 3 was confirmed by the X‐ray diffraction analysis, which revealed a highly symmetrical and remarkably bent syn‐form structure. The incorporation of bridge units with different electronic effects results in different photophysical properties of the cyclic ZnII porphyrin arrays. Comprehensive photophysical studies demonstrate that the electron‐withdrawing bridge fluorenone has the largest electronic interaction with the ZnII porphyrin unit among the series, thus resulting in the highest two‐photon absorption cross‐section values (σ(2)) of 6570±60 GM for 7 . The present work provides a new strategy for developing porphyrin‐based optical materials. 相似文献
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Nakamura Y Jang SY Tanaka T Aratani N Lim JM Kim KS Kim D Osuka A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(27):8279-8289
We report the synthesis and characterization of L- and T-shaped porphyrin tapes as extensible structural motifs of two-dimensionally extended porphyrin tapes. The two-photon absorption (TPA) cross-section values (sigma((2))) for L- and T-shaped porphyrin tapes as well as those for linear trimeric and tetrameric porphyrin tapes were measured by an open-aperture Z-scan method at 2300 nm, a wavelength at which the one-photon absorption contribution is either zero or almost negligible. Under these conditions, the sigma((2)) values for the linear porphyrin tape trimer and tetramer were determined to be 18 500 and 41 200 GM, respectively. The sigma((2)) value for the L-shaped trimer was determined to be 8700 GM, which is only half that of the linear trimer, whereas the sigma((2)) value for the T-shaped tetramer was measured to be 35 700 GM. These results clearly indicate the dependence of the TPA cross-section on the molecular shape, which underscores the importance of directionality in the pi-conjugation pathway for the enhancement of TPA cross- section. 相似文献
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K Naoda H Mori N Aratani BS Lee D Kim A Osuka 《Angewandte Chemie (International ed. in English)》2012,51(39):9856-9859
Gold standard: A bis(Au(III) ) complex containing the title compound was prepared and characterized (see scheme; DDQ=2,3-dichloro-5,6-dicyano-1,4-benzoquinone, Tf=trifluoromethanesulfonyl). Owing to the effective conjugative network over the flat and elongated rectangular molecular frame, this complex displays a remarkably red-shifted and sharp Q-band-like band at 1467?nm, multiple reversible redox potentials, and a large TPA cross-section value. 相似文献
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Inokuma Y Easwaramoorthi S Jang SY Kim KS Kim D Osuka A 《Angewandte Chemie (International ed. in English)》2008,47(26):4840-4843
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Miłosz Pawlicki Dr. Hazel A. Collins Dr. Robert G. Denning Prof. Harry L. Anderson Prof. 《Angewandte Chemie (International ed. in English)》2009,48(18):3244-3266
Two photons are better than one : This principle applies to a wide range of applications, ranging from engineering to physiology. Recent advances in our understanding of the phenomenon of two‐photon absorption (see picture) and in the design of two‐photon dyes are rapidly increasing the scope of this field.
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Synthetic expanded porphyrin chemistry 总被引:1,自引:0,他引:1
Expanded porphyrins are synthetic analogues of the porphyrins, and differ from these and other naturally occurring tetrapyrrolic macrocycles by containing a larger central core with a minimum of 17 atoms, while retaining the extended conjugation features that are a hallmark of these quintessential biological pigments. The result of core expansion is to produce systems with novel spectral and electronic features, interesting and, often unprecedented, cation-coordination properties, and, in many cases, an ability to bind anions in certain protonation states. Also adding to the appeal of expanded porphyrins is their central role in addressing issues of aromaticity. In many cases, they also display structural features, such as decidedly nonplanar "figure-eight" motifs, that have no antecedents in the chemistry of porphyrins or related macrocyclic compounds. In this Review, the various synthetic approaches now being employed to produce expanded porphyrins as well as their various applications-related aspects are discussed. 相似文献
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N‐Annulated Perylene‐Substituted and Fused Porphyrin Dimers with Intense Near‐Infrared One‐Photon and Two‐Photon Absorption 下载免费PDF全文
Dr. Jie Luo Sangsu Lee Minjung Son Dr. Bin Zheng Prof. Kuo‐Wei Huang Qingbiao Qi Wangdong Zeng Dr. Gongqiang Li Prof. Dongho Kim Prof. Jishan Wu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(9):3708-3715
Fusion of two N‐annulated perylene (NP) units with a fused porphyrin dimer along the S0–S1 electronic transition moment axis has resulted in new near‐infrared (NIR) dyes 1 a / 1 b with very intense absorption (ε>1.3×105 M ?1 cm?1) beyond 1250 nm. Both compounds displayed moderate NIR fluorescence with fluorescence quantum yields of 4.4×10?6 and 6.0×10?6 for 1 a and 1 b , respectively. The NP‐substituted porphyrin dimers 2 a / 2 b have also been obtained by controlled oxidative coupling and cyclodehydrogenation, and they showed superimposed absorptions of the fused porphyrin dimer and the NP chromophore. The excited‐state dynamics of all of these compounds have been studied by femtosecond transient absorption measurements, which revealed porphyrin dimer‐like behaviour. These new chromophores also exhibited good nonlinear optical susceptibility with large two‐photon absorption cross‐sections in the NIR region due to extended π‐conjugation. Time‐dependent density functional theory calculations have been performed to aid our understanding of their electronic structures and absorption spectra. 相似文献
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Yang J Lee JE Lee CY Aratani N Osuka A Hupp JT Kim D 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(33):9219-9225
Single-molecule photophysical properties of two families of linear porphyrin arrays have been investigated by single-molecule fluorescence detection techniques. Butadiyne-linked arrays (Z(N)B) with extensive π-conjugation perform as photostable one-quantum systems. This demonstration has been suggested by the long-lasting initial emissive state and subsequent discrete one-step photobleaching in the fluorescence intensity trajectories (FITs). As in the behavior of a one-quantum system, Z(N)B shows anti-bunching data in the coincidence measurements. On the other hand, in directly-linked arrays (Z(N)) with strong dipole coupling, each porphyrin moiety keeps individual character in photobleaching dynamics. The stepwise photobleachings in the FITs account for this explanation. Most of the FITs of Z(N) do not carry momentary cessation of fluorescence emission, which has been explained by the strongly bound electron-hole pair of Frenkel exciton that suppresses charge transfer between the molecule and surrounding polymers. These results give insight into the influences of interchromophorinc interactions between porphyrin moieties in the multiporphyrin arrays on their fluorescence dynamics at the single-molecule level. 相似文献
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Yasuo Tanaka Shohei Saito Shigeki Mori Naoki Aratani Dr. Hiroshi Shinokubo Prof. Dr. Naoki Shibata Prof. Dr. Yoshiki Higuchi Prof. Dr. Zin Seok Yoon Kil Suk Kim Su Bum Noh Jong Kang Park Dongho Kim Prof. Dr. Atsuhiro Osuka Prof. Dr. 《Angewandte Chemie (International ed. in English)》2008,47(4):614-614
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