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991.
Hironobu Tahara Yudai Tanaka Shoko Yamamoto Shigeki Yonemori Bun Chan Hiroto Murakami Takamasa Sagara 《Chemical science》2021,12(13):4872
Redox-active ionic liquids (RAILs) are gaining attention as a material that can create a wide range of functions. We herein propose a charge-transfer (CT) RAIL by mixing two RAILs, specifically a carbazole-based ionic liquid ([CzC4ImC1][TFSI]) as a donor and a viologen-based ionic liquid ([C4VC7][TFSI]2) as an acceptor. We investigated the effect of CT interaction on the physicochemical properties of the CT ionic liquid (CT-IL) using the results of temperature-dependent measurements of UV-vis absorption, viscosity, and ionic conductivity as well as cyclic voltammograms. We employed the Walden analysis and the Grunberg–Nissan model to elucidate the effect of the CT interaction on the viscosity and ionic conductivity. The CT interaction reduces the viscosity by reducing the electrostatic attraction between the dicationic viologen and TFSI anion. It also reduces the ionic conductivity by the CT association of the dicationic viologen and carbazole. The electrochemically reversible responses of the viologens in [C4VC7][TFSI]2 and CT-IL are consistent with the Nernstian and the interacting two-redox site models. Notably, the transport and electrochemical properties are modulated by CT interaction, leading to unique features that are not present in individual component ILs. The inclusion of CT interaction in RAILs thus provides a powerful means to expand the scope of functionalized ionic liquids.A redox-active ionic liquid (RAIL) consisting of a carbazole and viologen shows charge transfer (CT) interaction. The physicochemical properties are modulated by the CT interaction by comparison with the individual RAILs. 相似文献
992.
Michael Woolman Jimmy Qiu Claudia M. Kuzan-Fischer Isabelle Ferry Delaram Dara Lauren Katz Fowad Daud Megan Wu Manuela Ventura Nicholas Bernards Harley Chan Inga Fricke Mark Zaidi Brad G. Wouters James T. Rutka Sunit Das Jonathan Irish Robert Weersink Howard J. Ginsberg David A. Jaffray Arash Zarrine-Afsar 《Chemical science》2020,11(33):8723
Integration between a hand-held mass spectrometry desorption probe based on picosecond infrared laser technology (PIRL-MS) and an optical surgical tracking system demonstrates in situ tissue pathology from point-sampled mass spectrometry data. Spatially encoded pathology classifications are displayed at the site of laser sampling as color-coded pixels in an augmented reality video feed of the surgical field of view. This is enabled by two-way communication between surgical navigation and mass spectrometry data analysis platforms through a custom-built interface. Performance of the system was evaluated using murine models of human cancers sampled in situ in the presence of body fluids with a technical pixel error of 1.0 ± 0.2 mm, suggesting a 84% or 92% (excluding one outlier) cancer type classification rate across different molecular models that distinguish cell-lines of each class of breast, brain, head and neck murine models. Further, through end-point immunohistochemical staining for DNA damage, cell death and neuronal viability, spatially encoded PIRL-MS sampling is shown to produce classifiable mass spectral data from living murine brain tissue, with levels of neuronal damage that are comparable to those induced by a surgical scalpel. This highlights the potential of spatially encoded PIRL-MS analysis for in vivo use during neurosurgical applications of cancer type determination or point-sampling in vivo tissue during tumor bed examination to assess cancer removal. The interface developed herein for the analysis and the display of spatially encoded PIRL-MS data can be adapted to other hand-held mass spectrometry analysis probes currently available.Integration between a hand-held mass spectrometry desorption probe based on picosecond infrared laser technology (PIRL-MS) and an optical surgical tracking system demonstrates in situ tissue pathology from point-sampled mass spectrometry data. 相似文献
993.
Carbophilic Additions of Organocuprates and 1,3-Thiazole-5(4H)-thiones Organocuprates and 1,3-thiazole-5(4H)-thiones 1 react in THF at 0° via carbophilic addition onto the C? S bond to give 4,5-dihydro-1,3-thiazole-5-thiols 3 (Scheme 3). This observation is in marked contrast to the previously described reaction of organolithium compounds and 1 , which undergo a thiophilic addition onto the exocyclic S-atom. As an exception, treatment of the 1,3-thiazole-5(4H)-thione 1a with tert-butyl cuprate leads to 7a (Scheme 3). 相似文献
994.
Uwe Klingebiel Peter Werner Anton Meller 《Monatshefte für Chemie / Chemical Monthly》1976,30(6):939-943
The reaction of RSiCl3 (R=CH3, C2H5, C6H5) and R2SiCl2 (R=CH3) with one mole of the phosphenimidous amides R2N–P=NR [R=R=Si(CH3)3; R=Si(CH3)3, R=C(CH3)3] yieds a four membered PN2Si-ring system under elimination of (CH3)3SiCl. 相似文献
995.
Whitten AE Dittrich B Spackman MA Turner P Brown TC 《Dalton transactions (Cambridge, England : 2003)》2004,(1):23-29
High-resolution X-ray diffraction data have been collected on the cubic polymorph of antimony(III) oxide (senarmontite) to determine the charge distribution in the crystal. The results are in quantitative agreement with crystal Hartree-Fock calculations for this polymorph, and have been compared with theoretical calculations on the orthorhombic polymorph (valentinite). Information about the nature of bonding and relative bond strengths in the two polymorphs has been extracted in a straightforward manner via topological analysis of the electron density. All the close contacts in both polymorphs are found to be similar in nature based on the value of the Laplacian, the magnitude of the electron density and the local energy density at the bond critical points, and these characterise the observed interactions as substantially polar covalent, similar to molecular calculation results on Si-O and Ge-O. Electrostatic potential isosurfaces reveal the octopolar nature of this function for senarmontite, and shed light on the observed packing arrangement of Sb4O6 molecules in the crystal. 相似文献
996.
Tugarinov V Hwang PM Ollerenshaw JE Kay LE 《Journal of the American Chemical Society》2003,125(34):10420-10428
A comparison of HSQC and HMQC pulse schemes for recording (1)H[bond](13)C correlation maps of protonated methyl groups in highly deuterated proteins is presented. It is shown that HMQC correlation maps can be as much as a factor of 3 more sensitive than their HSQC counterparts and that the sensitivity gains result from a TROSY effect that involves cancellation of intra-methyl dipolar relaxation interactions. (1)H[bond](13)C correlation spectra are recorded on U-[(15)N,(2)H], Ile delta 1-[(13)C,(1)H] samples of (i) malate synthase G, a 723 residue protein, at 37 and 5 degrees C, and of (ii) the protease ClpP, comprising 14 identical subunits, each with 193 residues (305 kDa), at 5 degrees C. The high quality of HMQC spectra obtained in short measuring times strongly suggests that methyl groups will be useful probes of structure and dynamics in supramolecular complexes. 相似文献
997.
Thiolactosyl lipids designed for carbohydrate-protein binding studies have been synthesised. One representative was selected for binding studies with a plant lectin RCA120, the agglutinin from Ricinus communis. The interactions were measured quantitatively in real time using a BIAcore surface plasmon resonance instrument. Removal of much of the galactose from the thiolactosyl lipid in situ with beta-galactosidase showed that the lectin binding was highly specific. A dissociation constant KD = 8.77 x 10(-8) M was measured for 1-[2-[2-(2-[beta-D-galactopyranosyl-(1-->4)-1-thio-beta-D -glucopyranosyl]ethoxy)ethoxy]ethoxy]octadecane 30 which is four orders of magnitude greater than that determined for binding to lactose in solution. A concentration of lactose of > 80 mM was required to block the lectin binding to thiolactosyl lipid in a neomembrane. 相似文献
998.
Robert D. Gillard Robert J. Lancashire Peter A. Williams 《Transition Metal Chemistry》1979,4(2):115-118
Summary The reactions of [Fe(bipym)3]2+ and [Ru(bipym)3]2+ with hydroxide ion in aqueous solution have been followed. The [Ru(bipym)3]2+ species undergoes nucleophilic attack at the ligand to yield [Ru(bipym)2(pyrimidine)(OH)]+ and [HCO2]– ion, involving cleavage of one pyrimidyl ring. Intermediates can be observed in the reaction of [Fe(bipym)3]2+ with HO–, N3
– and SCN–. The kinetics of the first reaction have been followed and the results are compared with those known for the reactions of [Fe(bipy)3]2+, [Fe(phen)3]2+ and similar compounds.Part XXIII: P. A. Williams,Transition Met. Chem., 78/84. 相似文献
999.
Peter Graf Ekkehard Kaempf Klaus Reichlmeier Karl Bernhard 《Helvetica chimica acta》1977,60(7):2151-2154
Metabolism of Acetylenic Monocarboxylic and Dicarboxylic Acids Feeding of acetylenic monoacids with chain length of 11 to 18 C-atoms to rats led to excretion of dicarboxylic acids with retained triple bonds. 10-Octadecynoic acid led to the formation of metabolites with even and odd number of C-atoms, suggesting in addition to established ω- and β-oxidation an α-oxidative pathway. 相似文献
1000.
Patching SG Brough AR Herbert RB Rajakarier JA Henderson PJ Middleton DA 《Journal of the American Chemical Society》2004,126(10):3072-3080
We have devised methods in which cross-polarization magic-angle spinning (CP-MAS) solid-state NMR is exploited to measure rigorous parameters for binding of (13)C-labeled substrates to membrane transport proteins. The methods were applied to two proteins from Escherichia coli: a nucleoside transporter, NupC, and a glucuronide transporter, GusB. A substantial signal for the binding of methyl [1-(13)C]-beta-d-glucuronide to GusB overexpressed in native membranes was achieved with a sample that contained as little as 20 nmol of GusB protein. The data were fitted to yield a K(D) value of 4.17 mM for the labeled ligand and 0.42 mM for an unlabeled ligand, p-nitrophenyl beta-d-glucuronide, which displaced the labeled compound. CP-MAS was also used to measure binding of [1'-(13)C]uridine to overexpressed NupC. The spectrum of NupC-enriched membranes containing [1'-(13)C]uridine exhibited a large peak from substrate bound to undefined sites other than the transport site, which obscured the signal from substrate bound to NupC. In a novel application of a cross-polarization/polarization-inversion (CPPI) NMR experiment, the signal from undefined binding was eliminated by use of appropriate inversion pulse lengths. By use of CPPI in a titration experiment, a K(D) value of 2.6 mM was determined for uridine bound to NupC. These approaches are broadly applicable to quantifying binding of substrates, inhibitors, drugs, and antibiotics to numerous membrane proteins. 相似文献