14187-32-7, Name is Dibenzo-18-crown-6, molecular formula is C20H24O6, belongs to chiral-catalyst compound, is a common compound. In a patnet, once mentioned the new application about 14187-32-7, Product Details of 14187-32-7
Aspects of the electron paramagnetic resonance (EPR) spectra of C60n- fulleride ions (n = 2, 3) and the EPR signal observed in solid C60 are reinterpreted. Insufficient levels of reduction and the unrecognized presence of C120O, a ubiquitous and unavoidable impurity in air-exposed C60, have compromised most previously reported spectra of fullerides. Central narrow line width signals (“spikes”) are ascribed to C120On- (n = odd). Signals arising from axial triplets (g ? 2.0015, D = 26-29 G) in the spectrum of C602- are ascribed to C120On- (n = 2 or 4). Their D values are more realistic for C120O than C60. Less distinct signals from “powder” triplets (D ? 11 G) are ascribed to aggregates of C120On- (n = odd) arising from freezing nonglassing solvents. In highly purified samples of C60, we find no evidence for a broad ?30 G signal previously assigned to a thermally accessible triplet of C602-. The C602- ion is EPR-silent. Signals previously ascribed to a quartet state of the C603- ion are ascribed to C120O4-. Uncomplicated, authentic spectra of C60- and C603- become available when fully reduced samples are prepared under strictly anaerobic conditions from freshly HPLC-purified C60. Solid off-the-shelf C60 has an EPR signal (g? 2.0025, AHpp ? 1.5 G) that is commonly ascribed to the radical cation C60.+. This signal can be reproduced by exposing highly purified, EPR-silent C60 to oxygen in the dark. Doping C60 with an authentic C60.+6 salt gives a signal with much greater line width (AHpp = 6-8 G). It is suggested that the EPR signal in air-exposed samples of C60 arises from a peroxide-bridged diradical, ?C60-O-O-C60. or its decomposition products rather than from C60.+. Solid-state C60 is more sensitive to oxygen than previously appreciated such that contamination with C120O is almost impossible to avoid.
Balanced chemical reaction does not necessarily reveal either the individual elementary reactions by which a reaction occurs or its rate law.Product Details of 14187-32-7. In my other articles, you can also check out more blogs about 14187-32-7