Open metal sites are crucial in catalysis. We have used a "loose coordination strategy" (LCS) to preorganize open metal sites in gold cluster catalysts. A gold nanocluster with composition of [Au26(3,4-Me2-Ph-form)9(iPr2-imy)3(Me2S)](BF4)2(iPr2-imy = 1,3-Diisopropylimidazolium tetrafluoroborate, 3,4-Me2-Ph-form = N,N'-Di(3,4-dimethyl-phenyl)formamidine) (Au26) has been obtained by one pot synthesis, i.
View Article and Find Full Text PDFTailoring the surface ligands of metal nanoclusters is important for engineering unique configurations of metal nanoclusters. Thiacalix[4]arene has found extensive applications in the construction of metal nanoclusters. In this investigation, we present the synthesis and characterization of the first all-calixarene-protected silver nanoclusters, [Ag(CHCN)][Ag(BTCA)] (, HBTCA = -butylthiacalix[4]arene).
View Article and Find Full Text PDFIt is challenging to attain strong near-infrared (NIR) emissive gold nanoclusters. Here we show a rod-shaped cluster with the composition of [Au(p-MBT)(Hdppa)](SOCF) (1 for short, Hdppa is N,N-bis(diphenylphosphino)amine, p-MBT is 4-methylbenzenethiolate) has been synthesized. Single crystal X-ray structural analysis reveals that it has a rod-like face-centered cubic (fcc) Au kernel built from two interpenetrating bicapped cuboctahedral Au units.
View Article and Find Full Text PDFMetal nanoclusters have emerged as promising near-infrared (NIR)-emissive materials, but their room-temperature photoluminescence quantum yield (PLQY), especially in solution, is often low (<10%). We studied the photophysics of Au(BuPhC≡C) (Au) and its alloy counterpart AuCu(BuPhC≡C) (AuCu) (where Bu is -butyl and Ph is phenyl) and found that copper (Cu) doping suppressed the nonradiative decay (~60-fold less) and promoted intersystem crossing rate (~300-fold higher). The AuCu nanocluster exhibited >99% PLQY in deaerated solution at room temperature with an emission maximum at 720 nanometers tailing to 950 nanometers and 61% PLQY in the oxygen-saturated solution.
View Article and Find Full Text PDFThe study of comorbidity can provide new insights into the pathogenesis of the disease and has important economic significance in the clinical evaluation of treatment difficulty, medical expenses, length of stay, and prognosis of the disease. In this paper, we propose a disease association prediction model DapBCH, which constructs a cross-species biological network and applies heterogeneous graph embedding to predict disease association. First, we combine the human disease-gene network, mouse gene-phenotype network, human-mouse homologous gene network, and human protein-protein interaction network to reconstruct a heterogeneous biological network.
View Article and Find Full Text PDFFor the first time site-specific doping of silver into a spherical Au nanocluster has been achieved in [AuAg(MeOPhS)(PPh)] (BF) (AuAg) through a dual-ligand coordination strategy. Single crystal X-ray structural analysis shows that the cluster has a distorted centered icosahedral Au@AuAg core of symmetry, in contrast to the Au@Au kernel in the well-known [Au(SR)] (R = CHCHPh). An interesting feature is the coexistence of [Au(SPhOMe)] dimeric staples and [P-Au-SPhOMe] semi-staples in the title cluster, due to the incorporation of PPh.
View Article and Find Full Text PDFAn atomically resolved gold nanocluster Au(C≡CCH-2,4-F) () with an unusual 59 valence electrons has been synthesized. Single-crystal X-ray diffraction reveals that its Au kernel is a Au Marks decahedron capped by two Au units. The surface structure of consists of 20 linear Au(C≡CR) staples.
View Article and Find Full Text PDFGlioma, the most severe primary brain malignancy, has very low survival rates and a high level of recurrence. Nowadays, conventional treatments for these patients are suffering a similar plight owing to the distinctive features of the malignant gliomas, for example chemotherapy is limited by the blood-brain barrier while surgery and radiation therapy are affected by the unclear boundaries of tumor from normal tissue. In the present study, a novel superparamagnetic iron oxide (SPIO) nanoprobe for enhanced T2-weighted magnetic resonance imaging (MRI) was developed.
View Article and Find Full Text PDFMinimal drug leakage during blood circulation and intracellular drug delivery in tumor sites are of great significance in chemotherapeutics. Herein we propose an interlayer crosslinked polymeric micelle with tumor acidity and reduction dual sensitivity for highly efficient drug delivery to cancer cells. A novel copolymer mPEG-C[double bond, length as m-dash]N-PAsp(MEA)-CA was synthesized and self-assembled into a dual-sensitive interlayer-crosslinked micelle (ICM).
View Article and Find Full Text PDFBioorg Med Chem Lett
October 2011
5-Isoproyl-3,8-dimethylazulene derivatives were synthesized and evaluated for antigastric ulcer activity in vivo. Some of them possess the best activity against gastric ulcer with ulcer index values lower than the drug reference (omeprazole). The structure-activity relationship (SAR) shows that the lipophilic flat structure contributes to quite potent antigastric ulcer activity.
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