The quantum instanton approximation is used to compute kinetic isotope effects for intramolecular hydrogen transfer in cis-1,3-pentadiene. Due to the importance of skeleton motions, this system with 13 atoms is a simple prototype for hydrogen transfer in enzymatic reactions. The calculation is carried out using thermodynamic integration with respect to the mass of the isotopes and a path integr...

Statistical mechanics predicts that the design of pure organized heteropolymetallic chains of metal ions bound to linear receptors depends on controlled deviations from the mixing rule DeltaE(MiMj) = 1/2 (DeltaE(MiMi) + DeltaE(MjMj)), whereby DeltaE(MiMj) is the intramolecular intermetallic interaction between neighboring metal i and metal j along the receptor. A thorough investigation of linea...

We introduce a point of view for treating the dynamical tunneling splitting of symmetric local mode vibrational states in ABA molecules (A = H typically) which is the one we have employed in treating the vibrational spectroscopy of CH overtones in molecules such as (CXs),YCCH. Namely, the vibrational coupling corresponding to the dynamical tunneling in semiclassical mechanics via many intermedi...

A stereodivergent plan is presented leading to all eight stereoisomers of oseltamivir carboxylate (OC). Key chemical manoeuvers are (1) a three-component vinylogous Mukaiyama-Mannich reaction, which sets the whole carbon skeleton and heteroatom substituents, and (2) an intramolecular, silylative Mukaiyama aldol reaction, which creates the targeted carbocycle. The viability of the plan was demon...

We have calculated the reorganisation energy for the intramolecular electron transfer between the reduced type 1 copper site and the peroxy intermediate of the trinuclear cluster in the multicopper oxidase CueO. The calculations are performed at the combined quantum mechanics and molecular mechanics (QM/MM) level, based on molecular dynamics simulations with tailored potentials for the two copp...

Carbamoyl phosphate (CP) has a half-life for thermal decomposition of <2 s at 100 degrees C, yet this critical metabolic intermediate is found even in organisms that grow at 95-100 degrees C. We show here that the binding of CP to the enzymes aspartate and ornithine transcarbamoylase reduces the rate of thermal decomposition of CP by a factor of >5,000. Both of these transcarbamoylases use an o...

molecular structure, isomerism, conformational stability and intramolecular hydrogen bonding (ihb) of cis-enol forms of 1-(n-pyridyl)butane-1,3-diones (npbd) (n = 2, 3, or 4) have been investigated by means of density functional theory (dft) calculations. energy differences for all possible npbd cis-enol forms of isomers with respect to the most stable form of the corresponding isomer have been...

ni6(n2h4)6(so4)4(oh)2(h2o)8](so4)(h2o)10 complex was prepared according to literature report. the reaction between aforementioned complex via sodium alkoxides as a reactants, were carried out in the solid state. the [ni6(n2h4)6(so4)4(oh)2(h2o)8](so4)(h2o)10 undergoes an intramolecular two electrons oxidation-reduction reaction at room temperature and metallic nickel nanoparticles (ni1-ni5) was ...

ni6(n2h4)6(so4)4(oh)2(h2o)8](so4)(h2o)10 complex was prepared according to literature report. the reaction between aforementioned complex via sodium alkoxides as a reactants, were carried out in the solid state. the [ni6(n2h4)6(so4)4(oh)2(h2o)8](so4)(h2o)10 undergoes an intramolecular two electrons oxidation-reduction reaction at room temperature and metallic nickel nanoparticles (ni1-ni5) was ...

We have calculated the reorganization energy for the intramolecular electron transfer between the reduced type 1 copper site and the peroxy intermediate of the trinuclear cluster in the multicopper oxidase CueO. The calculations are performed at the combined quantum mechanics and molecular mechanics (QM/MM) level, based on molecular dynamics simulations with tailored potentials for the two copp...