Allenes, Proton-Proton Coupling Constants, Substituent Effects Four-bond proton-proton coupling constants in allenes are reported. The substituent effects on the coupling constants are discussed on the basis of the dual-substituent parameter approach. Furthermore, the coupling constants are related to quantumchemical indices (electron densities, overlap populations) obtained from semiempirical ...

Introduction: Recently, an approach exploiting the proton therapy biological enhancement by using Boron atoms injected inside a tumor, has been proposed. Three alpha particles with an average energy around 4MeV are emitted from the point of reaction between a proton and boron. In addition, the 719 keV prompt gamma emitted by the proton Boron fusion reactions can be used for on-...

Compound (N,N-bis (salicylidene) 1,2-diaminophenylene) was prepared by condensation of ethanolsolution of 2-Hydroxybanzaldehyde and 1,2-diaminophenylene. The compound was characterized by1H NMR, infrared spectroscopy (FT-IR) data and analytical data. The geometrical parameters andenergies have been obtained from Density Functional Theory (DFT) B3LYP method and Hartree-Fock (HF) method with 3-21...

According to current estimates, the photosynthetic water oxidase functions with a quite restricted driving force. This emphasizes the importance of the catalytic mechanisms in this enzyme. The general problem of coupling electron and proton transfer is discussed from this viewpoint and it is argued that 'weak coupling' is preferable to 'strong coupling'. Weak coupling can be achieved by facilit...

The membrane bound coupling factor of photophosphorylation is studied after pretreatment of broken chloroplasts with the bifunctional N,N-orthophenyldimaleimide under energization of the thylakoid membrane by mild flashing light. The proton conduction of the membrane is monitored both via the electrochromic absorption changes and via selective pH-indicating dyes. It is found that the coupling f...

Using hadronic Lagrangians that include the interaction of pentaquark Q+ baryon with K and N, we evaluate the cross sections for its production from meson-proton, proton-proton, and photon-proton reactions near threshold. With empirical coupling constants and form factors, the predicted cross sections are about 1.5 mb in kaon-proton reactions, 0.1 mb in r-nucleon reactions, 0.05 mb in pion-nucl...