排序方式: 共有51条查询结果,搜索用时 15 毫秒
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Dilcan Dirican Dr. Maria Talavera Prof. Dr. Thomas Braun 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(70):17707-17712
The electron-rich Pt complex [Pt(IMes)2] (IMes: [1,3-bis(2,4,6-trimethylphenyl)-2-imidazolinylidine]) can be used as precursor for the syntheses of a variety of fluorido ligand containing compounds. The sulfur fluoride SF4 undergoes a rapid oxidative addition at Pt0 to yield trans-[Pt(F)(SF3)(IMes)2]. A photolytic reaction of SF6 at [Pt(IMes)2] in the presence of IMes gave the fluorido complexes trans-[Pt(F)2(IMes)2] and trans-[Pt(F)(SF3)(IMes)2] along with trans-[Pt(F)(SOF)(IMes)2] and trans-[Pt(F)(IMes’)(IMes)] (IMes’: cyclometalated IMes ligand), the latter being products produced by reaction with adventitious water. trans-[Pt(F)(SOF)(IMes)2] and trans-[Pt(F)2(IMes)2] were synthesized independently by treatment of [Pt(IMes)2] with SOF2 or XeF2. A reaction of [Pt(IMes)2] with a HF source gave trans-[Pt(H)(F)(IMes)2], and an intermediate bifluorido complex trans-[Pt(H)(FHF)(IMes)2] was identified. Compound trans-[Pt(H)(F)(IMes)2] converts in the presence of CsF into trans-[Pt(F)(IMes’)(IMes)]. 相似文献
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M. Knecht H. Neufeld H. Rupertsberger P. Talavera 《The European Physical Journal C - Particles and Fields》2000,14(3):469-478
We construct a low-energy effective field theory which allows for a full treatment of the isospin-breaking effects in semileptonic
weak interactions. To this end, we enlarge the particle spectrum of chiral perturbation theory with virtual photons by including
also the light leptons as dynamical degrees of freedom. Using super-heat-kernel techniques, we determine the additional one-loop
divergences generated by the presence of virtual leptons and give the full list of associated local counterterms. We illustrate
the use of our effective theory by applying it to the decays and .
Received: 9 September 1999 / Published online: 10 December 1999 相似文献
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The weighted L
p
-spaces of entire analytic functions are generalized to the vector-valued setting. In particular, it is shown that the dual
of the space is isomorphic to when the function χ
K
is an L
p,ρ
(E)-Fourier multiplier. This result allows us to give some new characterizations of the so-called UMD-property and to represent
several ultradistribution spaces by means of spaces of vector sequences.
J. Motos is partially supported by DGI (Spain), Grant BFM 2002-04013 and Grant MTEM 2005-08350-C03-03. 相似文献
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Ruperto BermejoEmilio Fernández Jose M. Alvarez-PezEva M. Talavera 《Journal of luminescence》2002,99(2):113-124
The fluorescent properties of biliproteins (B-phycoerythrin, BPE; C-phycocyanin, CPC and allophycocyanin, APC) have been utilized as labels of nucleic acids to detect hybridization by means of steady-state fluorescence anisotropy in a homogeneous aqueous solution of model system in which poly(C) and poly(I) are, respectively, the probe and target sequences. An easy method to obtain biliprotein-DNA conjugates by a two-stage procedure is described. The first stage was a modification of the cytosine amino group of poly(C) at the N4 position which then reacted with N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP) to obtain poly(C)-bound 2-pyridyl disulfide. In the second stage biliproteins were directly reacted with SPDP to obtain biliprotein-bound 2-pyridyl disulfide, dithiotreitol was added for reduction to biliprotein-bound thiol and was then mixed with the poly(C)-bound 2-pyridyl disulfide to obtain the biliprotein-poly(C) conjugate. The three biliproteins studied bind to nucleic acids without noticeable change of their spectral properties (absorption, fluorescence efficiency and fluorescence lifetime). Consequently, our labeling methodology can be applied to obtain any type of biliprotein-labeled nucleic acid probe. The increase of the steady-state fluorescence anisotropy from biliprotein-poly(C) upon hybridization with poly(I) can be used to readily detect the hybridization with the target poly(I) in a sample without having to separate free and bound labeled probes. The small decreases in lifetime displayed by the biliprotein-poly(C) conjugates upon hybridization are not sufficient to explain the steady-state anisotropy increase. Apparently, the rotational motion of the overall macrostructure is principally responsible for the increase in anisotropy. The greater fluorescence efficiency and lifetime from BPE with respect to those from CPC or APC allows us recommend that protein as the most suitable label. 相似文献
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The process η → π0π0γγ is discussed in Chiral Perturbation Theory (ChPT). Special attention is deveted to one-loop corrections, η-η′ mixing effects and vector-meson dominance of ChPT counter-terms. The less interesting η → π+π−γγ transition is briefly discussed too. 相似文献
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Paredes JM Crovetto L Orte A Alvarez-Pez JM Talavera EM 《Physical chemistry chemical physics : PCCP》2011,13(4):1685-1694
The buffer-mediated proton-transfer reactions of the fluorescent xanthenic derivative 9-[1-(2-Methyl-4-methoxyphenyl)]-6-hydroxy-3H-xanthen-3-one (TG-II) have been studied in different aqueous media. We have employed various buffers to investigate the influence of donor/acceptor systems with different anion and/or cation chemical constituents on the kinetic parameters of proton-transfer. The kinetic parameters were recovered both in the ground-state by means of Fluorescence Lifetime Correlation Spectroscopy (FLCS) and in the excited-state by means of Time Correlated Single Photon Counting (TCSPC) and Global Compartmental Analysis (GCA). Both ground- and excited- deprotonation and protonation recovered rate constants in the presence of either phosphate or acetate buffer as donor/acceptor systems were similar. The presence of Tris-HCl buffer does not promote the excited-state proton-transfer (ESPT) reaction. The results indicate the influence of the ions on the ground-state proton-transfer (GSPT) rates and concomitantly on the ESPT reaction. The proton-transfer rate constants recovered here show a trend correlated with the Hofmeister series or the Marcus classification of ions. 相似文献