نتایج جستجو برای: trityl carbocation
تعداد نتایج: 615 فیلتر نتایج به سال:
Tris(2,3,5,6-tetrathiaaryl)methyl radicals, so-called trityl radicals, are emerging as spin labels for distance measurements in biological systems based on Electron Paramagnetic Resonance (EPR). Here, the synthesis and characterization of rigid model systems carrying either two or three trityl moieties is reported. The monofunctionalized trityl radicals are connected to the molecular bridging s...
Trityl based spin labels are emerging as a complement to nitroxides in nanometer distance measurements using EPR methods. The narrow spectral width of the trityl radicals prompts us to ask the question at which distance between these spin centers, the pseudo-secular part of the dipolar coupling and spin density delocalization have to be taken into account. For this, two trityl-trityl and one tr...
Density functional theory calculations on mechanisms of the formation of caryolene, a putative biosynthetic precursor to caryol-1(11)-en-10-ol, reveal two mechanisms for caryolene formation: one involves a base-catalyzed deprotonation/reprotonation sequence and tertiary carbocation minimum, whereas the other (with a higher energy barrier) involves intramolecular proton transfer and the generati...
We embedded an all-hydrocarbon-based carbocation in a metallic microcavity that was tuned to resonance with electronic transition of the carbocation. The measured Rabi splitting 41% excitation energy, putting system well into ultrastrong coupling regime. Importantly, due intrinsic charge on carbocation, polaritons form carry significant fraction $0.55 e_0$ and large charge-to-mass ratio ($\sim ...
Pulsed electron paramagnetic resonance (EPR) spectroscopy is a valuable technique for the precise determination of distances between paramagnetic spin labels that are covalently attached to macromolecules. Nitroxides have commonly been utilised as paramagnetic tags for biomolecules, but trityl radicals have recently been developed as alternative spin labels. Trityls exhibit longer electron spin...
Thymidine phosphorylase (TPase) is one of the key enzymes involved in the pyrimidine nucleoside salvage pathway. However, TPase also stimulates angiogenesis, and its expression correlates well with microvessel density and metastasis in a variety of human tumors. We have shown recently that 5'-O-trityl-inosine (KIN59) allosterically inhibits TPase enzymatic activity. KIN59 also inhibits TPase-in...
Glycans functionalised with hydrophobic trityl groups were synthesised and adsorbed onto polystyrene and glass slides in an array format. The adsorbed glycans could be analysed directly on these minimally conducting surfaces by MALDI-TOF mass spectrometry analysis after aluminium tape was attached to the underside of the slides. Furthermore, the trityl group appeared to act as an internal matri...
Spin labelling with trityls: to gather information about the structure and dynamics of trityl radicals, spin-labelled polymers were measured with pulsed electron-electron double resonance (PELDOR) and double-quantum coherence (DQC). This study demonstrates that trityl radicals have great potential as spin labels that eliminate some limitations of nitroxide spin labels.
Since the discovery of triphenylmethyl (trityl) cation 120 years ago, a variety aromatic cations having various colors and luminescence properties have been rigorously studied. Many, differently substituted trityl synthesized, their optical elucidated. However, parent, non-substituted highly reactive cation, which was observed to be very weakly luminescent, not subjected detailed investigation....
The synthesis under MW irradiation without solvent of 19 pyrazoles, of which only 8 were known, is described. They bear C-methyl groups and trityl, diphenylmethyl and benzyl groups at positions 1 and 4 of the pyrazole ring. In the reaction between pyrazole and trityl bromide an unexpected reaction occurred and 4-(9-phenyl-9H-fluoren-9-yl)-1Hpyrazole (7) was isolated.
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید