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91.
The 6,6‐Dicyanopentafulvene Core: A Template for the Design of Electron‐Acceptor Compounds 下载免费PDF全文
Dr. Aaron D. Finke Dr. Burkhard O. Jahn Dr. Anas Saithalavi Dr. Christian Dahlstrand Dr. Djawed Nauroozi Sophie Haberland Dr. Jean‐Paul Gisselbrecht Prof. Dr. Corinne Boudon Dr. Edgar Mijangos Dr. W. Bernd Schweizer Dr. Sascha Ott Dr. Henrik Ottosson Prof. Dr. François Diederich 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(22):8168-8176
The electron‐accepting ability of 6,6‐dicyanopentafulvenes (DCFs) can be varied extensively through substitution on the five‐membered ring. The reduction potentials for a set of 2,3,4,5‐tetraphenyl‐substituted DCFs, with varying substituents at the para‐position of the phenyl rings, strongly correlate with their Hammett σp‐parameters. By combining cyclic voltammetry with DFT calculations ((U)B3LYP/6‐311+G(d)), using the conductor‐like polarizable continuum model (CPCM) for implicit solvation, the absolute reduction potentials of a set of twenty DCFs were reproduced with a mean absolute deviation of 0.10 eV and a maximum deviation of 0.19 eV. Our experimentally investigated DCFs have reduction potentials within 3.67–4.41 eV, however, the computations reveal that DCFs with experimental reduction potentials as high as 5.3 eV could be achieved, higher than that of F4‐TCNQ (5.02 eV). Thus, the DCF core is a template that allows variation in the reduction potentials by about 1.6 eV. 相似文献
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K.Khairi H.Fong Kok Z.Lambak M.I.Abdan M.A.Farhan M.H.Othman M.L.H.Jamaluddin S.A.Mohamad Rofie Tee Din Chai K.Chia Ching A.Mohd.Ramli M.A.Mokhtar S.A.Syed Ahmad M.Mokhtar S.B.Ahmad Anas M.A.Mahdi 《中国光学快报(英文版)》2018,(4)
We experimentally designed dispersion-managed repeaterless transmission systems with a pre-compensation and post-compensation technique using multi-channel-chirped fiber Bragg gratings. The repeaterless transmission link supports a single channel(1548.51 nm) with a 10 Gbps repeaterless transmission system over 300 km standard single-mode fiber(SSMF). In the system design, two distributed Raman amplifiers(DRAs) were used to improve the signal level propagated along the 300 km SSMF. The co-propagating DRA provided 15 dB on–off gain and the counter-propagating produced 32 dB on–off gain at the signal wavelength. The experiment results show that the post-compensation configuration achieves an optimal performance with a bit error rate at 1 × 10~(-9). 相似文献
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Dr. Christophe Dussouy Dr. Laurent Bultel Dr. Julien Saguez Dr. Anas Cherqui Dr. Mounia Khelifa Dr. Eric Grand Prof. Philippe Giordanengo Prof. José Kovensky 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(32):10021-10028
The synthesis of four GlcNAc(β1→4)Glc disaccharides containing 2‐O‐acetyl and/or 6‐sulfate groups was performed in high yields with total 1,2‐trans stereoselectivity. These disaccharides were evaluated as candidates for insect chitinase inhibition and aphicidal activity. All the compounds prepared displayed physiological effects on M. persicae aphids; however, the inhibition of chitinases of different sources (bacteria, fungus, and aphid) followed different patterns according to subtle structural characteristics. 相似文献
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We develop an effective way to engineer a two-dimensional GaAs photonic crystal slab with its leaky eigenmodes at desired wavelengths by investigating its spectral dispersion, particularly in terms of transmission efficiency spectra at different launch angles of the light beam. Structural parameters for the photonic crystal slab with leaky eigenmode wavelengths at both 1492 nm and 1519 nm are obtained. This may lead to the enhanced luminescence from erbium-doped trinitride-template fullerenes (Er3N@C80) on the surface of the photonic crystal slabs. 相似文献
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Pentafulvenes undergo a facile [6+3] cycloaddition with 3-oxidopyrylium betaine, generated from the corresponding pyranulose acetate, leading to the formation of 5-8 fused oxabridged cyclooctanoids. The product is formed by a [6+3] cycloaddition, followed by a 1,5-hydrogen shift of the initially formed [6+3] adduct. The reaction was found to be general and a number of fulvenes with a wide range of substituents at the exocyclic double bond, that is, at the C6 position followed a similar reactivity pattern. The [6+3] adduct, a 5-8 fused oxabridged cyclooctanoid, is potentially amenable to a number of synthetic transformations due to the presence of an α,β-unsaturated ketone and cyclopentadiene part. By selecting appropriately substituted fulvene and pyranulose acetates, it is possible to use this methodology for the synthesis of a wide range of 5-8 fused cyclooctanoids. The experimental results have been rationalized on the basis of theoretical calculations. 相似文献
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Jackson M. Chitanda Haixia Zhang Erica Pahl Randy W. Purves Anas El-Aneed 《Journal of the American Society for Mass Spectrometry》2016,27(10):1686-1693
The utility of novel functionalized nanodiamonds (NDs) as matrices for matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) is described herein. MALDI-MS analysis of small organic compounds (<1000 Da) is typically complex because of interferences from numerous cluster ions formed when using conventional matrices. To expand the use of MALDI for the analysis of small molecules, novel matrices were designed by covalently linking conventional matrices (or a lysine moiety) to detonated NDs. Four new functionalized NDs were evaluated for their ionization capabilities using five pharmaceuticals with varying molecular structures. Two ND matrices were able to ionize all tested pharmaceuticals in the negative ion mode, producing the deprotonated ions [M – H]–. Ion intensity for target analytes was generally strong with enhanced signal-to-noise ratios compared with conventional matrices. The negative ion mode is of great importance for biological samples as interference from endogenous compounds is inherently minimized in the negative ion mode. Since the molecular structures of the tested pharmaceuticals did not suggest that negative ion mode would be preferable, this result magnifies the importance of these findings. On the other hand, conventional matrices primarily facilitated the ionization as expected in the positive ion mode, producing either the protonated molecules [M + H]+ or cationic adducts (typically producing complex spectra with numerous adduct peaks). The data presented in this study suggests that these matrices may offer advantages for the analysis of low molecular weight pharmaceuticals/metabolites. 相似文献
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Transition metal complexes of a hydrazone–oxime ligand containing the isonicotinoyl moiety: Synthesis,characterization and microbicide activities 下载免费PDF全文
Complexes of VO2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Ru3+ and UO22+ with (3‐(hydroxyimino)butan‐2‐ylidene)isonicotinohydrazide were synthesized and characterized using physical and spectral methods. Analytical data revealed that the complexes formed in 1:1 or 1:2 metal–ligand ratios. Spectral studies showed that the ligand bonded to the metal ion in neutral tridentate, monobasic tridentate or monobasic bidentate fashion through azomethine nitrogen atom, protonated/deprotonated imine oxime group and/or ketonic/enolic carbonyl group. From the electronic spectral data together with magnetic susceptibility values a square planar, tetrahedral or distorted octahedral structure can be proposed for all complexes. Electron spin resonance spectra for Cu2+ complexes ( 2 – 4 ) revealed axial symmetry with g|| > g⊥ > ge, indicating distorted octahedral or square planar structures and the unpaired electron exists in a orbital with marked covalent bond feature. The prepared complexes showed good to excellent biological activity, and the most active complexes against Aspergillus niger were 4 and 9 with zone of inhibition of 25 and 23 mm, respectively. Complexes 10 and 11 showed interesting activity against Escherichia coli with zone of inhibition of 44 and 32 mm, respectively. 相似文献