CHEMISTRY: Metal-Free Ringing
نویسندگان
چکیده
منابع مشابه
Chemistry and cooling in metal-free and metal-poor gas
I summarize four of the most important areas of uncertainty in the study of the chemistry and cooling of gas with zero or very low metallicity. These are: i) the importance and effects of HD cooling in primordial gas; ii) the importance of metal-line and dust cooling in low metallicity gas; iii) the impact of the large uncertainties that exist in the rate coefficients of several key reactions i...
متن کاملMetal-Free Polymethyl Methacrylate (PMMA) Nanoparticles by Enamine “Click” Chemistry at Room Temperature
“Click” chemistry has become an efficient avenue to unimolecular polymeric nanoparticles through the self-crosslinking of individual polymer chains containing appropriate functional groups. Herein we report the synthesis of ultra-small (7 nm in size) polymethyl methacrylate (PMMA) nanoparticles (NPs) by the “metal-free” cross-linking of PMMA-precursor chains prepared by reversible addition-frag...
متن کاملMetal-free dihydrogen activation chemistry: structural and dynamic features of intramolecular P/B pairs.
Hydroboration of allyl(dimesityl)phosphane with HB(C(6)F(5))(2) gives the intramolecular five-membered P-B Lewis pair 7, that was characterized by X-ray diffraction. Similarly, HB(C(6)F(5))(2) addition to the substrates (mesityl)(2)P-CR[double bond, length as m-dash]CH(2) (R = CH(3), Ph) yield the corresponding (mesityl)(2)P(micro-CHRCH(2))B(C(6)F(5))(2) products 9a (R = CH(3)) and 9b (R = Ph) ...
متن کاملAnion Redox Chemistry in the Cobalt Free 3d Transition Metal Oxide Intercalation Electrode Li[Li0.2Ni0.2Mn0.6]O2.
Conventional intercalation cathodes for lithium batteries store charge in redox reactions associated with the transition metal cations, e.g., Mn(3+/4+) in LiMn2O4, and this limits the energy storage of Li-ion batteries. Compounds such as Li[Li0.2Ni0.2Mn0.6]O2 exhibit a capacity to store charge in excess of the transition metal redox reactions. The additional capacity occurs at and above 4.5 V v...
متن کاملGreen chemistry: solvent- and metal-free Prins cyclization. Application to sequential reactions.
Prins cyclization between a homoallylic alcohol and an aldehyde, promoted by trimethylsilyl halide, afforded 4-halo-tetrahydropyrans with good to excellent yields. Thanks to the absence of the solvent and metal, the THP thus obtained have been implicated without purification in several other reactions, in a sequential way, affording in particular new indole derivatives.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Science
سال: 2007
ISSN: 0036-8075,1095-9203
DOI: 10.1126/science.315.5815.1055a