The velocity map ion imaging method is applied to the ion-molecule reactions of N(+) with CH(4). The velocity space images are collected at collision energies of 0.5 and 1.8 eV, providing both product kinetic energy and angular distributions for the reaction products CH(4)(+), CH(3)(+), and HCNH(+). The charge transfer process is energy resonant and occurs by long-range electron transfer that r...

The kinetics and mechanism of the photodeprotection and rearrangement reactions for the pHP phototrigger compounds p-hydroxyphenacyl diethyl phosphate (HPDP) and diphenyl phosphate (HPPP) were studied using transient absorption (TA) and picosecond time-resolved resonance Raman (ps-TR(3)) spectroscopy. TA spectroscopy was employed to detect the dynamics of the triplet precursor decay as well as ...

The primary step currently assumed in bacterial photosynthesis involves fast electron transfer between the electronically excited bacteriochlorophyll ‘special pair’ [l], ’ (BChl):, and a bacteriopheophytin, BPh, with a rate kR > (10 ps)-’ [2-41. In blocked reaction centers, the radical ions thus formed live for G 10 ns at 300 K [5] and decay by the back transfer of the electron. If this occurs ...

dicephalic parapagus tribrachius conjoined twin is a very rare condition. we present a case of 5-days-old male dicephalic parapagus conjoined twins. the conjoined twins were diagnosed in 4(th) month of pregnancy by ultrasonography. the pregnancy terminates at 36 weeks by cesarean section and triplets were born. the babies were male conjoined twins and another healthy male baby. many congenital ...

Aqueous nanoparticle (NP) dispersions are commonly used as model systems for spectro- scopic study of singlet exciton fission (SF) in acenes such 6,13-(triisopropylsilylethynyl) pentacene (TIPS-Pn). However, the potential particle size effects to complicate interpretation results is generally ignored. In this work, we amorphous TIPS-Pn NP prepared by re-precipitation method over a range sizes. ...

Emissive layers in phosphorescent organic light-emitting diodes commonly make use of guest–host blends such as Ir(ppy)3:CBP to achieve high external quantum efficiencies. However, while the blend has been studied experimentally, crucial questions remain regarding how exciton diffusion is dependent on distribution guest host, which can currently only be addressed at atomic level via computationa...

The dynamics of peptide α-helices have been studied extensively for many years, and the kinetic mechanism of the helix-coil dynamics has been discussed controversially. Recent experimental results have suggested that equilibrium helix-coil dynamics are governed by movement of the helix/coil boundary along the peptide chain, which leads to slower unfolding kinetics in the helix center compared w...

Mathematical methods have been developed to evaluate solid-state kinetics. They generally fall into two categories: model-fitting or model-free (isoconversional). Modelfitting methods determine the kinetic triplet (model, frequency factor and activation energy) whereas isoconversional (model-free) methods generate the activation energy as a function of reaction progress without modelistic assum...

Energy gaps, AXsar (X=E, H and G) (AX.,.,-=lia,„,,,InrX“dpka,) between single (s) and triplet (I) states werecalculated at B3LTP/6-3 I 1.HO" level of theory. Our results showed that electron donating substituents(G = -NHz, -OH. -CH), -F, -Cl and -Br) at phenyl group cause to increase and electron withdrawingsubstiluents (G -CF2. and -NO:) lead to decrease the singlet-triplet energy gaps of Ar -...

using hartree-fock su-sheriffer-heeger (hf-ssh) model, we have studied the dependence of the energies of the ground (magnetic triplet state) and the first exited (nonmagnetic singlet state) states of the size-2 trigonal zigzag graphene nanoflake (size-2 nf) on the intensity of an external in plane static electric field at zero temperature. we identify a transition from the magnetic triplet stat...