Harmonic interpolation of Hermite type based on Radon projections with constant distances

We study harmonic interpolation of Hermite type of harmonic functions based on Radon projections with constant distances of chords. We show that the interpolation polynomials are continuous with respect to the angles and the distances. When the chords coalesce to some points on the unit circle, we prove that the interpolation polynomials tend to a Hermite interpolation polynomial at the coalescing points.     

Theoretical study of low-lying triplet states of aniline

Multireference complete active space self-consistent-field CASSCF(10,12)/ANO and second-order perturbation theory MS-CASPT2 calculations were performed to determine the vertical low-lying singlet and triplet states of aniline. The sequence of the seven lower lying triplet states is T1(1(3)A'), T2(1(3)A' '), T3(2(3)A'), T4(3(3)A'), T5(2(3)A' '), T6(4(3)A'), and T7(3(3)A' '). The 3(3)A', 4(3)A', and 3(3)A' ' states are assigned as 3s, 3py, and 3pz Rydberg states, respectively, while other states correspond to pi <-- pi excitations. Both the T1 and T2 states are found to be below at the lowest-lying singlet S1 (1(1)A' ') state. Geometry, vibrational modes, and electron distribution of the lowest lying T1 state were determined using UB3LYP calculations. The vertical and adiabatic singlet-triplet energy gaps DeltaE(S0-T1) amount to 3.7 and 3.5 +/- 0.2 eV, respectively. In clear contrast with the S0 state, the triplet aniline is no longer aromatic, and its protonation occurs preferentially at the ring meta-carbon site, with a proton affinity PA = 243 +/- 3 kcal/mol.     

Chemical Constituents and Biological Activities of the Leaves of Knema saxatilis

Chemistry of Natural Compounds -     

Numerical study of wave overtopping of a seawall supported by porous structures

This paper presents a VOF-based two-phase flow model for the simulation of wave interactions with seawall supported by a porous terrace. Firstly, the model was verified against laboratory data in a simple case for wave overtopping of a vertical wall. Comparison of computed and measured wave properties showed reasonably good agreement. The model was then applied to study the interactions of waves and a seawall protected by porous structures with a permeable terrace. The application results showed that the overtopping rate was strongly related to the energy dissipation through the drag force; the porous reef and terrace were very effective to produce a low crest type seawall. It is concluded that there exist two optimum values of porosity of the submerged reef, about of 0.25 and 0.7, that give minimum overtopping rates. Whereas, there is an effective range of porosity of the permeable terrace varying from 0.4 to 0.65 for significantly reducing the overtopping rate. The verification results confirm that the VOF-based two-phase flow model is sufficient robust to simulate the wave overtopping of coastal structures with reasonable accuracy.     

A computational study of halomethyllithium carbenoid mixed aggregates with lithium halides and lithium methoxide

Density functional theory calculations were used to examine the formation of lithium halide and lithium alkoxide mixed aggregates with halomethyllithium carbenoids. These mixed aggregates may be the important intermediates in carbenoid reactions where lithium halides are formed as byproducts, or when the mixture has been exposed to small amounts of air. The calculations showed that in the gas phase and in THF solution, mixed dimers, trimers, and tetramers may coexist with free lithium carbenoids, depending on the lithium salt. The calculations also indicated that mixed aggregates may influence the activation free energies of cyclopropanation reactions of lithium carbenoids.     

Toward a better understanding on the mechanism of ortholithiation. Tuning of selectivities in the metalation of meta-anisic acid by an appropriate choice of base

[reaction: see text] If employed in THF at 0 degrees C, LTMP metalates meta-anisic acid at the doubly activated position. In contrast, n-BuLi/t-BuOK deprotonates position C-4 preferentially at low temperature. Functionalization at C-6 requires protection of the C-2 site beforehand. As a result of these findings, a new mechanism is proposed for the heteroatom-directed ortholithiation of aromatic compounds.