Three states global fittings with improved long range: singlet and triplet states of H+3

Full dimensional analytical fits of the coupled potential energy surfaces for the three lower singlet and triplet adiabatic states of H+3 are developed, providing analytic derivatives and non-adiabatic coupling matrix elements.

Quantum yields of singlet oxygen of tetrakis (4-carboxyphenyl) porphyrin in different solvents

The singlet oxygen quantum yields of photosensitizers in different solvents are very important for photodynamic therapy (PDT). Here, we investigated the singlet oxygen quantum yields of tetrakis (4-carboxyphenyl) porphyrin (TCPP) in various solvents by the iodide method. Results indicate that TCPP has different singlet oxygen formation efficiency in different solvents. When compared to TCPP dissolved in water, TCPP showed higher singlet oxygen yields in methanol and ethanol, but lower singlet oxygen yields in DMF under identical conditions. In particular, TCPP rapidly precipitated in acetone after potassium iodide added in the solution. The salting out effect of TCPP by potassium iodide in acetone was confirmed by re-dissolving the precipitation in water and the characteristic absorption of TCPP was measured. The phenomenon of salting out for TCPP in acetone suggests that acetone is not a good solvent for singlet oxygen generation when evaluated by the iodide method.

Synthesis and photobiological properties of novel silicon(IV) phthalocyanines axially modified by paracetamol and 4-hydroxyphenylacetamide

Two novel axial-disubstituted silicon(IV) phthalocyanines (compounds 1 and 2) have been prepared by introducing paracetamol (a common antipyretic analgesic) or its isomer 4-hydroxyphenylacetamide at the axial positions of silicon(IV) phthalocyanine, respectively. Their photophysical and biological properties have been examined. Both compounds are highly soluble and exhibit very similar absorption spectra in N, N-dimethylformamide, which is typical for non-aggregated phthalocyanines. Both compounds are photocytotoxic against HT29 human colon adenocarcinoma cells. Compound 2 shows a very high in vitro photodynamic activity, with the IC50 value down to 15 nM. In contrast, compound 1 exhibits a much lower in vitro photodynamic activity toward HT29 cells, which can be attributed to its higher aggregating trend in the biological medium and lower singlet oxygen quantum yield.

Electronic structure of lower singlet states of binuclear copper acetate monohydrate

The electronic structures of the ground state and the excited states due to the 3d–3d transition of copper acetate monohydrate are investigated by abinitio calculations. No direct bond is obtained between the two Cu ions, but they are bonded by bridges of the four acetates. The excited states represented by the one-electron excitation of an occupied 3d electron to an unoccupied 3d orbital in either of the two Cu's are located around 1.6-1.8 eV, which corresponds to the energy region of band I. Those of the simultaneous one-electron 3d–3d excitation in both Cu's (i.e., two-electron excitation) are located around 3.2–3.4 eV. They correspond to the energy region of band II. Keywords: copper acetate monohydrate, binuclear compound, bridged bond, 3d → 3d excited states.

Spezifische Wärme von CeCl3·7 H2O zwischen 1,1 und 3,3°K

The specific heat of monoclinic CeCl3 · 7 H2O was measured in the temperature range between 1,1 and 3,3°K. Assuming that the cerium-ions are arranged in isolated pairs with isotropic and antiferromagnetic coupling a value of k · 1,20°K is derived from the data for the energy separation between the lower singlet and the upper triplet state.