查看更多>>摘要：Three homoleptic tris-cyclometalated iridium (III) complexes (Irl-Ir3) based on a rigid aza-triptycene unit have been synthesized via a novel one-pot method. The coordination arrangement of Ir2 was revealed by single X-ray structural analysis and the molecule showed a facial configuration. These complexes exhibited excellent thermal stability with T_d of 454-520 °C. These complexes exhibit strong green phosphorescence emission with high quantum yields of over 70% due to the introduction of aza-triptycene skeleton with rigid steric hindrance reduced intermolecular interactions. Accordingly, the electroluminescence device based on Irl, Ir2 and Ir3 exhibit high-brightness of 42194, 48807 and 46332 cd m~2, maximum luminous efficiency of 21.0, 24.7 and 28.5 cd A~(-1) and high EQE of 6.3, 6.8 and 8.9% at a high doping concentration of 30 wt%. Meanwhile, the non-doped green devices based on Irl, Ir2 and Ir3 give high-brightness of 20571, 15407 and 10707 cd m~2 and luminous efficiency of 8.5, 9.5 and 5.4 cd A-1, respectively. These results suggest that these materials have potential application in OLEDs.
查看更多>>摘要：A system comprising cucurbit[8]uril (Q[8]) and a fluorescent molecule (E)-l-(2-hydroxyethyl)-4-(4-hydrox-ystyryl)pyridin-l-ium bromide (HPy) has been utilized to construct a fluorescent probe that is capable of detecting the pesticide tricyclazole (TC). A variety of techniques including ~1H NMR spectroscopy together with fluorescence experiments have been employed to investigate the host-guest properties of the Q[8]/HPy system in aqueous solution. Results indicate that the system forms the stable2:l inclusion complex HPy2@Q[8], and that this inclusion complex imparts fluorescent quenching on HPy. The addition of a number of pesticides was found to have no obvious effect on the fluorescence, however on addition of tricycazole (TC), the fluorescence intensity underwent a dramatic enhancement. The linear relationship between the fluorescence intensity and the concentration of TC allowed for the facile detection of TC concentration in aqueous target solutions as well as in agricultural products. The detection limit was found to be 3.70 x 10~(-8) mol L~(-1).
查看更多>>摘要：In this paper, a series of oc-cyano-l,4-diphenylbutadiene derivatives containing triphenylamine structure were designed and synthesized. By changing the connection mode of the terminal diphenylamine, tire angle between the donor and the acceptor was adjusted to further regulate the fluorescent wavelengths of la-lh from 456 run to 621 nm in solution and 515 nm-614 nm in solid states.
Yury A. BelousovVladislav M. KorshunovMikhail T. Metlin
11页
查看更多>>摘要：With the aim of creating new light emitting systems, two new dysprosium complexes of formula [DyQcy3(H20)] (1-Dy) and [H3O] [DyQ~(cy)4] (2-Dy) (where HQcy = l-phenyl-3-methyl-4-cyclohexylcarbonyl-pyrazol-5-one) have been synthesized and characterized by spectroscopy. The reaction conditions to address the synthesis toward these tris-(diketonate)dysprosium or tetrakis(diketonate)dysprosium complexes have been optimized. The Qcy ligand provides effective sensitization of the luminescence of Dy~(3+) ion. 1-Dy and 2-Dy have been investigated by single crystal X-ray diffraction analysis, both species being packed via a system of hydrogen bonds. The dependence of quantum yield and lifetime of the excited state of Dy~(3+) ions have been examined by implementing two common approaches: replacing protons with deuterium in the coordinated H2O or in cation H3O+ and diluting Dy~(3+) cations with Gd~(3+) ions, to suppress vibrational and concentration quenching, respectively. It has been found that deuteration turns out to be very effective on both quantum yield and lifetime, but only in the case of replacement of the inner-sphere water molecules. The strategy of gadolinium dilution leads in all cases to an increase in lifetime. In addition, the possibility of a subtle tuning of the luminescence color has been discovered due to the change in the gadolinium content and deuteration, and a white light luminescent (CIE 0.31, 0.34) composition has been obtained.
查看更多>>摘要：Carboxylesterases (CEs) are involved in biotransformation of numerous drugs, environmental toxicants, and carcinogens containing ester groups. Abnormal CEs levels are associated with various diseases. Herein, we developed a novel water-soluble merocyanine-based probe 1 to detect CEs activity using acetate ester as a recognition site. The notable emission at 510 nm of the probe in neat aqueous solution was partially quenched and red-shifted to 580 nm after adding CEs. The fluorescent ratiometric response of 1 toward CEs activity is sensitive (with the detection limit of 0.98 x 10~(-6) U/ml), rapid (within 10 min), and effective in a wide pH range (4.0-10.0). Due to the existence of morpholine as a lysosome-targeting group, the probe was successfully utilized to monitor lysosomal CEs activity. More importantiy, the probe was successfully applied to detect and image carboxylesterase activity in zebrafish.
查看更多>>摘要：The high toxicity and side effects of drugs as well as the difficulty of tracking their trends and metabolism have always been the core difficulties of anticancer drugs. In this paper, doxorubicin (DOX) was used as therapeutic drug to coordinate with Mn~+ to obtain the hydrophobic core of nanomedicine. The outer layer was self-assembled and coated with amphiphilic block copolymer-distearyl phosphatidylethanolamine-polyethylene glycol (DSPE-mPEG2000) to form Mn-DOX@DSPE-mPEG2000 micellar nanoparticles (MDDM NPs) with good dispersion and stability. Cell experiments showed that MDDM micellar nanoparticles could be effectively uptaked by cells in a short time, and had good biocompatibility and tumor inhibition. In vivo experiments have shown that nanoparticles not only have excellent therapeutic effects, but also have magnetic resonance imaging contrast as contrast agents due to Mn~(2+) coordination, which can assist in tracking drug trends and metabolism in vivo. The above work provides a certain reference significance for the study of combining organic drugs with metals to realize the reduction of drug toxicity and provide multimodal function of metals.
查看更多>>摘要：As a star polymer acceptor, N2200 got great attention once emerging. However, some of its properties, like poor miscibility with donors, relatively deep lowest unoccupied molecular orbital (LUMO) energy level, restrict its application. In general, random copolymerization can be used to perform partial substitution in polymers to achieve simple performance regulation. In this work, we obtained a new acceptor polymer PNDIOD-30Se based on N2200 by partially replacing thiophene with selenophene. At optimal condition, the power conversion efficiency of the devices based on PTBD-BZ: PNDIOD-30Se was over to 6.42% with a high open circuit voltage of 0.91 V. The blend film was more uniform, and got nanophase separation domain. The results indicate that incorporating selenophene by random copolymerization into n-type polymer could simply adjust the properties of the polymer acceptor for all-polymer solar cells.
查看更多>>摘要：Discovery of organic luminophores with unique properties typically leads to new applications of such emitters in the field of organic optoelectronics. The example is demonstrated in this study. One of the newly synthesized mechanochromic derivatives of benzanthrone and carbazole demonstrates ability of self-regulation of its solid-state structure and related light-emitting properties. This compound shows intensive green emission peaking at 537 nm in the initial state, weak yellowish green emission peaking at 557 nm after mechanical treatment which self-recovers back to intensive green emission with the intensity maximum at 539 nm. The processes are completely reversible. They include the following set of states: highly emissive state->damaged weak-emissive state self-recovering recovered highly emissive state. The developed compound is a very rare example of materials which can be used for security probes or data/code writing with recovering ability after mechanical damage. Variety of experimental studies including spectroscopy of thermally annealed samples and single crystal and powder diffraction X-ray analysis revealed the ability of the developed derivatives of benzanthrone and carbazole to form different polymorphs and aggregates in solid-state responsible for their multicolour mechanochromic emission.
查看更多>>摘要：The addition of a functional third component in PM6:Y6 system has demonstrated great potential in achieving highly power conversion efficiency (PCE) for organic solar cells (OSCs). However, photocurrent generation is still limited by slow hole transfer from Y6 to PM6. Herein, a non-fullerene acceptor BTP-eC9, with high hole-mobility property, is incorporated into the PM6:Y6 blend to construct a ternary system. The good compatibility of acceptors with similar chemical structure is conducive to simultaneously fine-tune the morphology, energy level and spectra absorption. Moreover, the introduction of BTP-eC9 endows the active layer with high hole mobility and balanced electron and hole transfer, further achieving the increased short-circuit current density {Jsc) and fill factor (FF). The optimized ternary OSCs give an improved PCE of 16.39%, which makes a significant enhancement compared to binary devices based on PM6:Y6 and PM6:BTP-eC9 (14.87% and 13.27%, respectively).
查看更多>>摘要：This work reported an economical and sensitive fluorescence sensor for mercury (II) ions based on the cetyltrimethylammonium bromide-mediated nitrogen-doped carbon dots (NCDs). The NCDs, obtained by a sol-vothermal method, exhibit emission with low quantum yield (6%) that can be quenched by various ions such as Cu~(2+), Cr~(6+), Co~(2+), and Hg~(2+). After adding cetyltrimethylammonium bromide (CTAB), the two produced aggregation-induced fluorescence effect, coupled with electrostatic interaction, and the quantum yield increased to 32%. The spatial structure formed by CTAB/NCDs could selectively capture Hg~(2+) and make interact with the surface groups of NCDs to cause fluorescence quenching. The fluorescence intensity and Hg~(2+) concentration showed a linear response in die range of 0.15-1 mM and 0.16-10.24 |iM (R2 = 0.998), and the detection limit was 85.71 nM. The fluorescent sensor was used to determine Hg~(2+) in environmental waters with satisfactory results.
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