منابع مشابه
Hydrogen-Abstraction/Acetylene-Addition Exposed.
Polycyclic aromatic hydrocarbons (PAHs) are omnipresent in the interstellar medium (ISM) and also in carbonaceous meteorites (CM) such as Murchison. However, the basic reaction routes leading to the formation of even the simplest PAH-naphthalene (C10 H8 )-via the hydrogen-abstraction/acetylene-addition (HACA) mechanism still remain ambiguous. Here, by revealing the uncharted fundamental chemist...
متن کاملSingle-Acetylene Linked Porphyrin Nanorings
The synthesis of ethyne-linked porphyrin nanorings has been achieved by template-directed Sonogashira coupling. The cyclic hexamer and octamer are predicted by density functional theory to adopt low symmetry conformations, due to dihedral twists between neighboring porphyrin units, but their symmetries are effectively D6h and D8h, respectively, in solution by 1H NMR. The fluorescence spectra in...
متن کاملHexaphenylbenzenes as potential acetylene sponges.
Acetylene sponges can be created by taking advantage of the nonplanar geometry of hexaphenylbenzenes and the special capacity of the central aromatic ring to engage in C(sp)-H...pi interactions reinforced by secondary C(sp(2))-H...pi interactions, as revealed by X-ray crystallographic studies and DFT calculations.
متن کاملAcetylene inhibition of Azotobacter vinelandii hydrogenase: acetylene binds tightly to the large subunit.
Acetylene is a slow-binding inhibitor of the Ni- and Fe-containing dimeric hydrogenase isolated from Azotobacter vinelandii. Acetylene was released from hydrogenase during the recovery from inhibition. This indicates that no transformation of acetylene to another compound occurred as a result of the interaction with hydrogenase. However, the release of C2H2 proceeds more rapidly than the recove...
متن کاملAnalysis of acetylene reduction rates of soybean nodules at low acetylene concentrations.
It has been previously proposed that acetylene reduction data at subsaturating acetylene concentrations could be interpreted by use of the Michaelis-Menten equation, based on the acetylene concentration external to the nodules. One difficulty of this view is that the assumption that the system is not diffusion limited is violated when studying intact nodules. The presence of a gas diffusion bar...
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ژورنال
عنوان ژورنال: Scientific American
سال: 1895
ISSN: 0036-8733
DOI: 10.1038/scientificamerican02161895-15952supp