Nitration equilibrium in the meso-erythritol-aqueous nitric acid system

Twelve equilibrium constants have been measured from 16 for sequential-parallel reactions in meso-erythritol nitration to the fully nitrated compound in aqueous HNO₃. Free-energy changes during nitration of the aliphatic polyatomic alcohols, glycerol and meso-erythritol, are highest when diprimary dinitrates (NOON) and (NON) are produced.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2248–2253, October, 1991.     

Catalytic and asymmetrizing activity of mixed copper-nickel catalysts,deposited on aerosil,in the hydrogenation of acetylacetone

Conclusions A mixed Cu-Ni (11) catalyst, deposited on aerosil and modified with D-(+)-tartarie acid, was obtained, which is active in theselective stereoselective hydrogenation of acetylacetone to the (-)-ketol. The optical yield of the ketol is 9.1% at 133°.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 680–682, March, 1977.     

Synthesis of derivatives of 5-azabenzofuran with functional substitutes in positions 4 and 7

Methods for synthesizing derivatives of 5-azabenzofuran with functional substitutes in position 4 and 7 have been elaborated. The reactions of electrophilic substitution in position 7 have been studied.An examination was made of the substitution of halogens in position 4 of derivatives of 5-azabenzofuran by the methoxy-group during the action of dimethyl sulfate in an aqueous alkali medium.     

Synthesis of derivatives of 3-amino- and 3-aminomethylquinuclidine

Various methods of preparing 3-aminoquinuclidine from quinuclid-3-one oxime and hydrazone are developed. Quinuclidine derivatives with a substituted amino group at position 3 are synthesized.     

Interrogating conformationally dependent electron-transfer dynamics via ultrafast visible pump/IR probe spectroscopy

We demonstrate for the first time the utility of time-resolved visible pump/mid-infrared (IR) probe spectroscopy to interrogate directly, and provide unique infomation regarding, conformationally dependent photoinduced ET dynamics and the subsequent structural evolution of the resulting charge-separated (CS) state. Exemplary polarized visible pump/IR probe experiments involving N-[5-(10,20-diphenylporphinato)zinc(II)]-N'(octyl)pyromellitic diimide (PZn-PI) and [5-[4'-(N-(N'-octyl)pyromellitic diimide)phenyl)ethynyl]-10,20-diphenylporphinato]zinc(II) (PZn()PI) show that it is possible to assess the mean PZn-to-PI interplanar torsional angle of electronically excited structural conformers that undergo ET within the sub-ps time domain for both of these donor-spacer-acceptor (D-Sp-A) systems. Further transient specroscopic experiments carried out on PZn()PI determine how this angle evolves with time. Because vibrational transition moments are often known and typically localized, this work underscores that polarized visible pump/IR probe spectroscopy defines a valuable tool to interrogate structrure in both electronically excited and CS states; this fact, coupled with the ultrafast time resolution and high senseitivity offered by this technique, make it ideally suited to probe a range of mechanistic issues relevant to charge-transfer reactions.     

Narrowing the window for millicharged particles by CMB anisotropy

We calculate the cosmic microwave background (CMB) anisotropy spectrum in models with millicharged particles of electric charge q～10^?6?10^?1 in units of electron charge. We find that a large region of the parameter space for the millicharged particles exists where their effect on the CMB spectrum is similar to the effect of baryons. Using WMAP data on the CMB anisotropy and assuming the Big Bang nucleosynthesis value for the baryon abundance, we find that only a small fraction of cold dark matter, Ω_mcp<0.007 (at 95% CL), may consist of millicharged particles with the parameters (charge and mass) from this region. This bound significantly narrows the allowed range of the parameters of millicharged particles. In models without paraphotons, millicharged particles are now excluded as a dark matter candidate. We also speculate that recent observation of 511-keV γ rays from the Galactic bulge may be an indication that a (small) fraction of cold dark matter is comprised of millicharged particles.