The enhanced reactivity of the Huisgen 1,3-dipolar cycloaddition between the protonated forms of azidoethylamine and propargylamine inside the cucurbit[6]­uril host has been computationally studied. A DFT approach is applied to explore the relative stabilities and connections of a large variety of possible host–guest aggregates that may be formed in solution, as well as their reactivity. The free energies resulting from the DFT calculations are converted to rate and dissociation constants and introduced, together with the experimentally reported initial concentrations, in a kinetic simulation. The results reproduce the experimental observations and provide a detailed description of the behavior of a large host–guest system over time. The major cause of the rate acceleration inside the nanovessel is the reduction of the entropic component of the free energy barrier, and the existence of stable nonproductive host–guest adducts is identified as a major obstacle to improved catalysis.

Using ab-initio molecular dynamics, we report a detailed exploration of the thermal motion occurring in perovskite crystals of formula CH 3 NH 3 PbI 3 . We exploit the data generated to obtain estimates of the rotational relaxation time of the cation CH 3 NH + 3 . We examine the tetragonal and cubic phase, as both may be present under operational conditions. Influenced by each other, and by the tilting of PbI 6 octahedra, cations undergo collective motion as their contribution to polarization does not vanish. We thereby qualitatively describe the modus operandi of formation of microscopic ferroelectric domains. Graphical TOC Entry

Linear 2-coordinate d10 Au(i) complexes could form Au(iii) species by oxidative addition with reasonable energies, although the barriers to access them are prohibitively high.

Rutile-TiO2/hybrid halide perovskite CH3NH3PbI3-xClx interfaces are investigated by ab initio density functional theory calculations. The role of chlorine in achieving enhanced solar cell power conversion efficiencies is in the focus of recent studies, which point to increased carrier mobilities, reduced recombination rates, a driven morphology evolution of the perovskite layer and improved carrier transport across the interface. As it was recently established that chlorine is preferentially localized in the vicinity of the interface and not in the bulk of the perovskite layer, we analyze the changes introduced in the electronic properties by varying the chlorine concentration near the interface. In particular, we discuss the effects introduced in the electronic band structure and show the role of chlorine in the enhanced electron injection into the rutile-TiO2 layer. Taking into account these implications, we discuss the conditions for optimizing the solar cell efficiency in terms of interfacial chlorine concentration.