Vinyl cyclopropane rearrangement (VCPR) has been utilised to synthesise a difluorinated cyclopentene stereospecifically and under mild thermal conditions. Difluorocyclopropanation chemistry afforded ethyl 3-(1'(2'2'-difluoro-3'-phenyl)cyclopropyl) propenoate as all four stereoisomers (18a, 18b, 22a, 22b) (all racemic). The trans-E isomer (18a), prepared in 70 % yield over three steps, underwent...

The optical spectra of nine dinitroaromatic radical anions (1,2- and 1,4-dinitrobenzene, 1,5- and 2,6-dinitro naphthalene, 4,4'-dinitrobiphenyl, 2,7-dinitro-9,9-dimethylfluorene, 2,6-dinitroanthracene, and 2,7- and 1,8-dinitrobiphenylene) in dimethylformamide are reported and analyzed. All have delocalized charge distribution, as demonstrated by the vibrational fine structure that is observed i...

The time-resolved mechanisms for eight Diels-Alder reactions have been studied by quasiclassical trajectories at 298 K, with energies and derivatives computed by UB3LYP/6-31G(d). Three of these reactions were also simulated at high temperature to compare with experimental results. The reaction trajectories require 50-150 fs on average to transverse the region near the saddle point where bonding...

Ammonium dinitramide (ADN) has been studied quantum chemically at the level of UB3LYP/6-31++G(d,p) in order to get some information about its behavior in the presence of some group II and III elements (viz., Be, Mg, B and Al). The results indicate that Be and Mg are being oxidized by AND, but B and Al are not. In the case of Be and Mg, the reduction of ADN is accompanied by the removal of NO2 m...

The first representatives of the radical anions of silatranes XSi(OCH2CH2)3N – organic derivatives of the pentacoordinate silicon atom (X = Ph, 1; p-NO2PhO, 2a; m-NO2PhO, 2b; o-NO2PhO, 2c) – were obtained and characterized by EPR spectroscopy. The structure of 1(−˙), 2a(−˙), 2b(−˙), and 2c(−˙) in polar solvents (C-PCM and COSMO models) was studied at the UMP2 and UB3PW91 levels of theory. The v...

Amide-iminol tautomerism was studied for ionized oxamic acid (OA+•) in the gas phase using theDFT method with the UB3LYP functional and various basis sets {6-31++G(d,p), 6-311+G(d,p), and augcc-pVDZ}. Among twenty tautomers-rotamers possible for OA+•, eleven isomers were found to bethermodynamically stable. Similarly as for the neutral molecule, ionization (OA → OA+• + e) favors theamidization ...

The pure rotational spectrum of the open shell difluorocyanomethyl radical, ĊF2CN, has been measured using two Balle-Flygare-type cavity Fourier-Transform-Microwave (FTMW) spectrometers both equipped with pulsed discharge nozzles. A total 156 transitions (from N = 1 – 0 to 6 5, and Ka 0, 1, 2, 3) in electronic ground state were observed between 6.5 GHz 38.4 a typical linewidth ∼5 kHz full-width...

Comprehensive studies of the molecular and electronic structures, vibrational frequencies, and infrared and Raman intensities of the aniline radical cation, C6H5NH2 1 have been performed by using the unrestricted density functional ~UB3LYP! and second-order Møller–Plesset ~UMP2! methods with the extended 6-31111G~df,pd! basis set. For comparison, analogous calculations were carried out for the ...

amide-iminol tautomerism was studied for ionized oxamic acid (oa+•) in the gas phase using thedft method with the ub3lyp functional and various basis sets {6-31++g(d,p), 6-311+g(d,p), and augcc-pvdz}. among twenty tautomers-rotamers possible for oa+•, eleven isomers were found to bethermodynamically stable. similarly as for the neutral molecule, ionization (oa → oa+• + e) favors theamidization ...