1186-73-8Relevant articles and documents
Synthesis and spectroscopic characterization of the first symmetrically and nonsymmetrically substituted fluorinated emerald-green trannulenes C 60F15R3 soluble in polar media and water
Troshin, Pavel A.,Khakina, Ekaterina A.,Zhilenkov, Alexander V.,Peregudov, Alexander S.,Troshina, Olesya A.,Kozlovskii, Viacheslav I.,Polyakova, Natalya V.,Lyubovskaya, Rimma N.
, p. 1037 - 1045 (2010)
The first water-soluble C3V-symmetrical trannulene derivatives of fluorofullerene C60F18 possessing six carboxylic or ammonium ion groups have been synthesized and spectrally characterized. The stability of emerald-green aqueous solutions of these compounds was investigated. A novel, synthetic route was developed for a step-by-step derivatization of C60F18 with different organic C-H acids that: yielded nonsymmetrically substituted C60F15R 2R trannulenes. The synthesized trannulenes were loaded with polar carboxylic groups that improved greatly the solubility of these compounds in aqueous media, We showed that four solubilizing COOH groups could be introduced onto the fullerene cage of C60F15R2R' trannulenes with R substituent and then some additional organic functionality could be attached independently with R', The R' substituent might potentially comprise a ligand responsible for selective targeting of the whole trannulene molecule to some specific tissues or intracellular structures. The demonstrated loading of the fluorofullerene core with polar carboxylic or ammonium groups might be considered as an important step towards the design of sophisticated water-soluble trannulene-based assembles for biomedical applications.
Enols of 2-nitro- and related 2-substituted malonamides
Basheer, Ahmad,Mishima, Masaaki,Rappoport, Zvi
scheme or table, p. 255 - 265 (2010/09/07)
The structures of 2-substituted malonamides, YCH(CONR1R 2)CONR3R4 (Y=Br, SO2Me, CONH 2, COMe, and NO2) were investigated. When Y=Br, R 1R2=R3R4=HEt; Y=SO2Me, R1-R4=H and for Y=CONH2 or CONHPh, R 1-R4=Me, the structure in solution is that of the amide tautomer. X-ray crystallography shows solid-state amide structures for Y=SO 2Me or CONH2, R1-R4=H. Nitromalonamide displays an enol structure in the solid state with a strong hydrogen bond (O. . .O distance=2.3730 A at 100 K) and d(OH) 6≠d(O. . .H). An apparently symmetric enol was observed in solution, even in appreciable percentages in highly polar solvents such as DMSO-d6, but Kenol values decrease on increasing the solvent polarity. The N,N′-dimethyl derivative is less enolic. Acetylmalonamides display a mixture of enol on the acetyl group and amide in non-polar solvents, and only the amide in DMSO-d6. DFT calculations gave the following order of pKenol values for Y: H > CONH 2 > COMe ≥ COMe (on acetyl) ≥ MeSO2>CN> NO2 in the gas phase, CHCl3, and DMSO. The enol on the C=O group is preferred to the aci-nitro compound, and theN-O-H. . .O=C is less favored than the C=O-H. . .O=C hydrogen bond. Copyright
Substituent Effects on the C-C Bond Strength, 19. Geminal Substituent Effects, 10. Radical Stabilization Enthalpies of α,α-Bis(methoxycarbonyl)alkyl and Tris(methoxycarbonyl)methyl Radicals
Rakus, Klaus,Verevkin, Sergey P.,Keller, Manfred,Beckhaus, Hans-Dieter,Ruechardt, Christoph
, p. 1483 - 1494 (2007/10/02)
Heats of formation ΔH0f(g) were determined from enthalpies of combustion ΔH0f(c) and enthalpies of vaporization ΔH0vap or sublimation ΔH0sub for the eight substituted methanetricarboxylates 2a-h.From these data and from previously determined enthalpies of formation ΔH0f of substituted malonic esters new thermochemical group increments were derived.From these increments and from the recently published improved increments for carboxylic acid esters the gem. interaction enthalpies of two and three COOR groups were calculated.The radical stabilization enthalpies RSE of α,α-bis(methoxycarbonyl)alkyl (18.2 kJ mol-1, 1a) and tris(methoxycarbonyl)methyl radicals (5.2 kJ mol-1, 1b) were derived from kinetic data obtained by means of our previously developed protocol.They were corrected for the gem. interaction energies of the ester groups in the ground state and are satisfactorily explained by an additive stabilizing effect for the ester substituents and by dipolar substituent interactions in the radicals.The dipolar energies were taken from MM2 calculations. - Keywords: Enthalpies of formation / Geminal substituents, energetic interaction of / Bond cleavage, C-C, kinetics of / Radicals, stabilization of / Increments, thermochemical, of esters
