Connected Triple Excitations in the Calculation of the Adiabatic Excitation Energies in the Equation-of-Motion Coupled Cluster Theory

The importance of the connected triple excitations (T ₃ operator) in the calculations of the adiabatic excitation energies are estimated for two diatomic closed shell molecules: N₂ and CO. The computations are carried out using the recently developed equation-of-motion (EOM) approach with full inclusion of the connected triple excitations [Kucharski, S. A., Woch, M., Musia, M., Bartlett, R. J. J. Chem. Phys. 2001, 115, 8263.] The effect of the T ₃ operator on the calculated excitation energies ranges from 0.1 to 0.3 eV significantly improving the results for all considered states. In all but one case the agreement with the experimental data is better than 0.05 eV.     

Melting and high-temperature solid state transitions in cobalt(II) halides

Melting and high temperature solid-state transitions in CoCl₂ and CoBr₂ are widely discussed. On the basis of DSC and conductometric measurements it was found that melting process of CoCl₂ is preceded by a solid-state transition appearing about 20 K below the melting point of CoCl₂. Due to deconvolution of the thermograms, the enthalpy of fusion and that of solid-state transition were found to be 36.4 and 9.6 kJ mol^–1, respectively. Melting points of CoCl₂ and CoBr₂ were established to be 999.0 and 949.7 K, respectively. Hitherto unknown enthalpy of fusion of CoBr₂ was determined to be 27.2 kJ mol^–1. A solid-state transition in CoBr₂ at 650 K has been confirmed.     

Potentiometric titration of trace amounts of mercury after a preliminary separation by a reduction method

Isolation and concentration of mercury by reduction of mercury(II) with acidic tin(II) chloride solution and absorption of mercury vapour in acidic permanganate solution is combined with potentiometric titration with dithiooxamide. The simple procedure is applicable to 5–100 ppb mercury in 1-dm³ samples. Recoveries from organomercurials are discussed.     

Application of anoxic fixed film and aerobic CSTR bioreactor in treatment of nanofiltration concentrate of real textile wastewater

An anoxic fixed film bioreactor (FFB) with biomass immobilized on activated carbon and an aerobic continuous stirred tank bioreactor with overflow were applied to degrade concentrate from nanofiltration of real textile effluents containing Reactive Red 120 (RR-120). The efficiency of color removal was 99 % irrespective of the fraction of nanofiltration concentrate in the feed. An approximate dye balance based on the assessed adsorption capacity of RR-120 by activated carbon indicated that the dye was removed by means of adsorption as well as of biological processes. Aromatic amine released from a dye molecule was fully adsorbed by activated carbon. COD level in the outflow of the system was above that imposed by legislation. Despite an adjustment of the feed pH to 7 this was constantly increasing up to the value above 9 in both reactors. Neither the nanofiltration concentrate nor the effluents from the bioreactors affected the growth of Pseudomonas putida used as toxicity indicator.     

Differential subordination related to conic sections

In this paper some problems of the theory of differential subordination are investigated in connection with conic domains. In particular, fundamental conditions for functions mapped the unit disk onto domains bounded by parabolas and hyperbolas are deduced.     

Highly enantioselective conjugate addition of diethylzinc to enones using aziridine-functionalized tridentate sulfinyl ligands

Enantiomerically pure tridentate heteroorganic catalysts, containing hydroxyl, sulfinyl, and aziridine moieties, have proven to be highly efficient in the enantioselective conjugate diethylzinc addition to chalcone and cyclohexenone to give the desired products in very high yields (up to 95%) and with ee’s up to 93%. The influence of the stereogenic centers located on the sulfinyl sulfur atom and in the aziridine moiety on the stereochemical course of the reaction is discussed.     

Existence results for evolutionary inclusions and variational–hemivariational inequalities

We consider an abstract first-order evolutionary inclusion in a reflexive Banach space. The inclusion contains the sum of L-pseudomonotone operator and a maximal monotone operator. We provide an existence theorem which is a generalization of former results known in the literature. Next, we apply our result to the case of nonlinear variational–hemivariational inequalities considered in the setting of an evolution triple of spaces. We specify the multivalued operators in the problem and obtain existence results for several classes of variational–hemivariational inequality problems. Finally, we illustrate our existence result and treat a class of quasilinear parabolic problems under nonmonotone and multivalued flux boundary conditions.     

Molecule-solid interaction: Electronic states of anthracene-9-carboxylic acid adsorbed on the surface of TiO2

Electronic excited states of athracene-9-carboxylic acid chemisorbed on the surface of TiO₂ nanoparticles were investigated by means of the electroabsorption (Stark effect) spectroscopy at low temperature. In addition to a fraction of molecules adsorbed with no significant spectral changes, two forms absorbing at lowered energy (25,600 cm⁻¹ and 24,900 cm⁻¹) were observed, that exhibit a large increase in the excited-minus-ground state dipole moments, 2.7 D and 9.5 D, respectively, as well as changed molecular polarizabilities. The dipole moments are interpreted as indicators of partial charge-transfer character of the excited state, corresponding to the optical electron transfer from the adsorbate onto TiO₂ concomitantly with the photon absorption. Consequences of these observations are shortly discussed in the context of the electron transfer process in dye-sensitized solar cells.