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Near‐Infrared Phosphorus‐Substituted Rhodamine with Emission Wavelength above 700 nm for Bioimaging 下载免费PDF全文
Dr. Xiaoyun Chai Xiaoyan Cui Baogang Wang Fan Yang Yi Cai Prof. Qiuye Wu Dr. Ting Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(47):16754-16758
Phosphorus has been successfully fused into a classic rhodamine framework, in which it replaces the bridging oxygen atom to give a series of phosphorus‐substituted rhodamines (PRs). Because of the electron‐accepting properties of the phosphorus moiety, which is due to effective σ*–π* interactions and strengthened by the inductivity of phosphine oxide, PR exhibits extraordinary long‐wavelength fluorescence emission, elongating to the region above 700 nm, with bathochromic shifts of 140 and 40 nm relative to rhodamine and silicon‐substituted rhodamine, respectively. Other advantageous properties of the rhodamine family, including high molar extinction coefficient, considerable quantum efficiency, high water solubility, pH‐independent emission, great tolerance to photobleaching, and low cytotoxicity, stay intact in PR. Given these excellent properties, PR is desirable for NIR‐fluorescence imaging in vivo. 相似文献
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Epitaxial Seeded Growth of Rare‐Earth Nanocrystals with Efficient 800 nm Near‐Infrared to 1525 nm Short‐Wavelength Infrared Downconversion Photoluminescence for In Vivo Bioimaging 下载免费PDF全文
Rui Wang Xiaomin Li Lei Zhou Prof. Dr. Fan Zhang 《Angewandte Chemie (International ed. in English)》2014,53(45):12086-12090
Novel β‐NaGdF4/Na(Gd,Yb)F4:Er/NaYF4:Yb/NaNdF4:Yb core/shell 1/shell 2/shell 3 (C/S1/S2/S3) multi‐shell nanocrystals (NCs) have been synthesized and used as probes for in vivo imaging. They can be excited by near‐infrared (800 nm) radiation and emit short‐wavelength infrared (SWIR, 1525 nm) radiation. Excitation at 800 nm falls into the “biological transparency window”, which features low absorption by water and low heat generation and is considered to be the ideal excitation wavelength with the least impact on biological tissues. After coating with phospholipids, the water‐soluble NCs showed good biocompatibility and low toxicity. With efficient SWIR emission at 1525 nm, the probe is detectable in tissues at depths of up to 18 mm with a low detection threshold concentration (5 nM for the stomach of nude mice and 100 nM for the stomach of SD rats). These results highlight the potential of the probe for the in vivo monitoring of areas that are otherwise difficult to analyze. 相似文献
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Inside Cover: Epitaxial Seeded Growth of Rare‐Earth Nanocrystals with Efficient 800 nm Near‐Infrared to 1525 nm Short‐Wavelength Infrared Downconversion Photoluminescence for In Vivo Bioimaging (Angew. Chem. Int. Ed. 45/2014) 下载免费PDF全文
Rui Wang Xiaomin Li Lei Zhou Prof. Dr. Fan Zhang 《Angewandte Chemie (International ed. in English)》2014,53(45):11988-11988
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Back Cover: Near‐Infrared Phosphorus‐Substituted Rhodamine with Emission Wavelength above 700 nm for Bioimaging (Chem. Eur. J. 47/2015) 下载免费PDF全文
Dr. Xiaoyun Chai Xiaoyan Cui Baogang Wang Fan Yang Yi Cai Prof. Qiuye Wu Dr. Ting Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(47):17132-17132
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A Diradical Approach towards BODIPY‐Based Dyes with Intense Near‐Infrared Absorption around λ=1100 nm 下载免费PDF全文
Dr. Yong Ni Sangsu Lee Minjung Son Prof. Dr. Naoki Aratani Masatoshi Ishida Dr. Animesh Samanta Prof. Dr. Hiroko Yamada Prof. Dr. Young‐Tae Chang Prof. Dr. Hiroyuki Furuta Prof. Dr. Dongho Kim Prof. Dr. Jishan Wu 《Angewandte Chemie (International ed. in English)》2016,55(8):2815-2819
A diradical approach to obtain stable organic dyes with intense absorption around λ=1100 nm is reported. The para‐ and meta‐quinodimethane‐bridged BODIPY dimers BD‐1 and BD‐2 were synthesized and were found to have a small amount of diradical character. These molecules exhibited very intense absorption at λ=1088 nm (?=6.65×105 M ?1 cm?1) and 1136 nm (?=6.44×105 M ?1 cm?1), respectively, together with large two‐photon‐absorption cross‐sections. Structural isomerization induced little variation in their diradical character but distinctive differences in their physical properties. Moreover, the compounds showed a selective fluorescence turn‐on response in the presence of the hydroxyl radical but not with other reactive oxygen species. 相似文献
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Designing Upconversion Nanocrystals Capable of 745 nm Sensitization and 803 nm Emission for Deep‐Tissue Imaging 下载免费PDF全文
Liangliang Liang Dr. Xiaoji Xie Dr. Daniel Teh Boon Loong Prof. Angelo Homayoun All Prof. Ling Huang Prof. Xiaogang Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(31):10801-10807
A crystal design strategy is described that generates hexagonal‐phased NaYF4:Nd/Yb@NaYF4:Yb/Tm luminescent nanocrystals with the ability to emit light at 803 nm when illuminated at 745 nm. This is accomplished by taking advantage of the large absorption cross‐section of Nd3+ between 720 and 760 nm plus efficient spatial energy transfer and migration through Nd3+→Yb3+→Yb3+→Tm3+. Mechanistic investigations suggest that a cascaded two‐photon energy transfer upconversion process underlies the emission mechanism. This protocol enables deep‐tissue imaging to be achieved while mitigating the attenuation effect associated with the visible emission and the overheating constraint imposed by conventional 980 nm excitation. 相似文献
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Jae Sung Son Xiao‐Dong Wen Dr. Jin Joo Dr. Jungseok Chae Sung‐il Baek Kunsu Park Jeong Hyun Kim Dr. Kwangjin An Dr. Jung Ho Yu Soon Gu Kwon Sang‐Hyun Choi Dr. Zhongwu Wang Dr. Young‐Woon Kim Prof. Young Kuk Prof. Roald Hoffmann Prof. Taeghwan Hyeon Prof. 《Angewandte Chemie (International ed. in English)》2009,48(37):6861-6864
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Low (15 nM) limits of detection (LOD) of dopamine were obtained at porous 1–3 nm‐thick overoxidized polypyrrole (OPPY) membrane‐coated microdisk carbon fiber electrodes of small size (r=3.5 µm). The excellent mass transport through the porous OPPY membrane (efficiency as good as solution transport) contributes to the low LOD, together with dopamine preconcentration in the membrane. Structural characterization of the membrane coated electrodes confirms the contribution of membrane nanostructure to the high sensitivity and the low LOD. 相似文献
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Cedric L. Hugelshofer Thomas Magauer 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(42):11533-11537
The first asymmetric total synthesis of the antifeedant terpenoids (+)‐norleucosceptroid A, (−)‐norleucosceptroid B, and (−)‐leucosceptroid K has been accomplished. This highly concise synthetic route was guided by our efforts to develop a platform for the collective synthesis of a whole family of antifeedant natural products. The synthesis features a Hauser–Kraus‐type annulation followed by an unprecedented, highly efficient intramolecular dilactol aldol‐type condensation reaction to produce the 5,6,5 skeleton. The developed synthetic route proceeds for norleucosceptroid A and B in 16 steps (longest linear sequence) from known compounds. 相似文献
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Dr. Joel Torres‐Alacan Oliver Krahe Prof. Dr. Alexander C. Filippou Prof. Dr. Frank Neese Prof. Dr. Dirk Schwarzer Prof. Dr. Peter Vöhringer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(10):3043-3055
The photochemistry of iron azido complexes is quite challenging and poorly understood. For example, the photochemical decomposition of [FeIIIN3(cyclam‐ac)]PF6 ([ 1 ]PF6), where cyclam‐ac represents the 1,4,8,11‐tetraazacyclotetradecane‐1‐acetate ligand, has been shown to be wavelength‐dependent, leading either to the rare high‐valent iron(V) nitrido complex [FeVN(cyclam‐ac)]PF6 ([ 3 ]PF6) after cleavage of the azide Nα? Nβ bond, or to a photoreduced FeII species after Fe? Nazide bond homolysis. The mechanistic details of this intriguing reactivity have never been studied in detail. Here, the photochemistry of 1 in acetonitrile solution at room temperature has been investigated using step‐scan and rapid‐scan time‐resolved Fourier transform infrared (FTIR) spectroscopy following a 266 nm, 10 ns pulsed laser excitation. Using carbon monoxide as a quencher for the primary iron‐containing photochemical product, it is shown that 266 nm excitation of 1 results exclusively in the cleavage of the Fe? Nazide bond, as was suspected from earlier steady‐state irradiation studies. In argon‐purged solutions of [ 1 ]PF6, the solvent‐stabilized complex cation [FeII(CH3CN)(cyclam‐ac)]+ ( 2 red ) together with the azide radical (N3.) is formed with a relative yield of 80 %, as evidenced by the appearance of their characteristic vibrational resonances. Strikingly, step‐scan experiments with a higher time resolution reveal the formation of azide anions (N3?) during the first 500 ns after photolysis, with a yield of 20 %. These azide ions can subsequently react thermally with 2 red to form [FeIIN3(cyclam‐ac)] ( 1 red ) as a secondary product of the photochemical decomposition of 1 . Molecular oxygen was further used to quench 1 red and 2 red to form what seems to be the elusive complex [Fe(O2)(cyclam‐ac)]+ ( 6 ). 相似文献
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Dylan Dagoneau Zhengren Xu Qian Wang Jieping Zhu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(2):770-773
A divergent total synthesis of three structurally distinct natural products from imine 9 was accomplished through an approach featuring: 1) a Pd‐catalyzed decarboxylative cross‐coupling, and 2) heteroannulation of 9 with bromoacetaldehyde and oxalyl chloride to give tetrahydroindolizine 6 and dioxopyrrole 7 , respectively. The former was converted into (−)‐rhazinilam, while the latter was converted into (−)‐leucomidine B and (+)‐leuconodine F. A substrate‐directed highly diastereoselective reduction of a sterically unbiased double bond by using a homogeneous palladium catalyst was developed. A self‐induced diastereomeric anisochronism (SIDA) phenomenon was observed for leucomidine B. 相似文献