Collisionally assisted spectroscopy of water from 27,000 to 34,000 cm(-1)

We report here an experimental approach that enables measurement of weak transitions to a wide range of rovibrational levels of water in the energy region 27,000-34,200 cm(-1). We have previously demonstrated the use of laser double-resonance overtone excitation to access highly excited vibrational levels from single rovibrational states. Although this approach simplifies the assignment of the spectra, it strongly reduces the number of observed transitions and hence our ability to test theoretical predictions. Here, we increase significantly the number of observed transitions by allowing rotational relaxation of H2O at intermediate levels of the double-resonance excitation scheme to the levels of the same nuclear spin (ortho or para). Our recently developed semiempirical potential energy surface PES12 enables assignment of the resulting complex spectra and reproduction of the measured transitions with accuracy better than 1 cm(-1).     

Strong solutions and trajectory attractors to the thin-film equation with absorption

We prove local and global in time existence of non-negative weak solutions to the thin-film equation with absorption and obtain sufficient conditions for extra regularity of these solutions. Moreover, for the class of global strong solutions, we show existence of a trajectory attractor.     

Photoinduced charge transfer in short-distance ferrocenylsubphthalocyanine dyads

Two new ferrocenylsubphthalocyanine dyads with ferrocenylmethoxide (2) and ferrocenecarboxylate (3) substituents directly attached to the subphthalocyanine ligand via the axial position have been prepared and characterized using NMR, UV-vis, and magnetic circular dichroism (MCD) spectroscopies as well as X-ray crystallography. The redox properties of the ferrocenyl-containing dyads 2 and 3 were investigated using the cyclic voltammetry (CV) approach and compared to those of the parent subphthalocyanine 1. CV data reveal that the first reversible oxidation is ferrocene-centered, while the second oxidation and the first reduction are localized on the subphthalocyanine ligand. The electronic structures and nature of the optical bands observed in the UV-vis and MCD spectra of all target compounds were investigated by a density functional theory polarized continuum model (DFT-PCM) and time-dependent (TD)DFT-PCM approaches. It has been found that in both dyads the highest occupied molecular orbital (HOMO) to HOMO-2 are ferrocene-centered molecular orbitals, while HOMO-3 as well as lowest unoccupied molecular orbital (LUMO) and LUMO+1 are localized on the subphthalocyanine ligand. TDDFT-PCM data on complexes 1-3 are consistent with the experimental observations, which indicate the dominance of π-π* transitions in the UV-vis spectra of 1-3. The excited-state dynamics of the dyads 2 and 3 were investigated using time-correlated single photon counting, which indicates that fluorescence quenching is more efficient in dyad 3 compared to dyad 2. These fluorescence lifetime measurements were interpreted on the basis of DFT-PCM calculations.     

Sorption Characteristics of Porous Styrene-Divinylbenzene Copolymers Filled with Modified Silica

The structural parameters of porous styrene-divinylbenzene copolymer, unfilled and filled with silica containing surface trimethylsilyl and silicon hydride groups were studied by aniline and p-chloroaniline adsorption. It has been shown that embedding of chemically modified silica affects the material porosity and decreases the copolymer swelling in benzene.