This work is a study of the competition between the two unimolecular reaction channels available to the vinoxy radical (CH(2)CHO), C-H fission to form H+ketene, and isomerization to the acetyl radical (CH(3)CO) followed by C-C fission to form CH(3) + CO. Chloroacetaldehyde (CH(2)ClCHO) was used as a photolytic precursor to the vinoxy radical in its ground state; photodissociation of chloroaceta...

Gas-phase dissociations were investigated for several peptide ions containing the Gly-Leu* N-terminal motif where Leu* was a modified norleucine residue containing the photolabile diazirine ring. Collisional activation of gas-phase peptide cations resulted in facile N₂ elimination that competed with backbone dissociations. A free lysine ammonium group can act as a Brønsted acid to facilitate N₂...

Crossed molecular beam reactions were exploited to elucidate the chemical dynamics of the reactions of phenyl radicals with isoprene and with 1,3-pentadiene at a collision energy of 55 ± 4 kJ mol(-1). Both reactions were found to proceed via indirect scattering dynamics and involve the formation of a van-der-Waals complex in the entrance channel. The latter isomerized via the addition of the ph...

The reactions of atomic carbon, C(P j), with benzene, C6H6(X A1g), and with d6-benzene, C6D6(X A1g) were investigated at twelve collision energies between 8.8 and 52.5 kJ mol 21 using the crossed molecular beams technique. Forward-convolution fitting of the data, high-level electronic structure calculations, and Rice–Ramsperger–Kassel–Marcus ~RRKM! investigations on the singlet and triplet C7H6...

The reaction of ground-state cyano radicals, CN(X(2)Σ(+)), with the simplest polyene, 1,3-butadiene (C4H6(X(1)Ag)), is investigated to explore probable routes and feasibility to form pyridine at ultralow temperatures. The isomerization and dissociation channels for each of the seven initial collision complexes are characterized by utilizing the unrestricted B3LYP/cc-pVTZ and the CCSD(T)/cc-pVTZ...

The chemical reaction dynamics to form cyanoacetylene, HCCCN (X S), via the radical–neutral reaction of cyano radicals, CN(X S;n50), with acetylene, C2H2(X Sg ), are unraveled in crossed molecular beam experiments at two collision energies of 21.1 and 27.0 kJ mol. Laboratory angular distributions and time-of-flight spectra of the HCCCN product are recorded at m/e551 and 50. Experiments were sup...

The unimolecular decomposition of CH3CH2OH has been investigated at the G2M (RCC2) level of theory. The decomposition reaction was found to be dependent strongly on pressure and temperature. Among the 8 product channels identified, the H2O-elimination process (1) via a four-member-ring transition state is dominant below 10 atm in the temperature range of 700 – 2500 K. At the high – pressure lim...

in past, the relationship between traditional learning theories and neurophysiological theories wasn’t a close relationship. recently, new findings in neurological sciences showed relatively simple neuron mechanisms for somewhat complicated learning events, for example observational learning, one of which is mirror neurons. these neurons show that how the brain registers the activity observed a...

most of the time, groups/communities are involved in negotiations and disputations due to their various interests. they are always trying to pursuit their aspiration to embrace changes and influence on events. although sometimes these groups are not completely opposed to each other and their intention is just to get the desired results, almost always their conditions are in contrast with each o...

the main purpose of this research is to describe emergent approach of grounded theory methodology and then compare it with systematic approach. to do so, after describing emergent approach, it compare it with systematic one surrounding 5 axis: coding processes; sampling processes; paradigms; literature review and rigor considerations. the findings show that emergent approach in comparison with ...