Band 8, Heft 1

It was found that thiourea, N-methylthiourea, N,N′-dimethylthiourea and N-allylthiourea accelerate the electroreduction process of In(III) ions in chlorates(VII). These substances are adsorbed on mercury from chlorates(VII). The relative surface excesses of thiourea and its derivatives increase with the increase of their concentrations and electrode charge. After adding thiourea, N-methylthiourea, N,N′-dimethylthiourea and N-allylthiourea to the solution an acceleration of the electroreduction process of In(III) ions occurs. This process depends on two factors: the adsorption of an accelerating substance on mercury and on the formation of complexes between a depolarizer and an accelerating substance on the electrode surface. The equilibrium of this complexing reaction determines the magnitude of the catalytic effect.

A green, mild and efficient method for Knoevenagel condensation of 3-formylchromone/2-chlroquinoline-3-carbaldehyde with active methylene compounds such as Meldrum’s acid/ethyl cyanoacetate using biosupported cellulose sulphuric acid (CSA) in the solid-state by grinding under solvent-free condition has been developed. This method provides several advantages including environmental friendliness, shor t reaction times, high yields and a simple work-up procedure. Moreover, the CSA was successfully reused for four cycles without significant loss of activity.

A mesoporous graphite material micro-structured with palladium-platinum deposits (mixed in the ratio of 70:30% Pd:Pt) has been used as a cost-effective electrode material for designing an amperometric biosensor for xanthine. The here reported biosensor shows significantly improved operational parameters as compared to previously published results. At a constant applied potential of −0.05 V (vs. Ag/AgCl) it is distinguished with enhanced selectivity of the determination: at the working potential the current from the electrochemical transformation of various electrochemically active substances usually attending biological fluids (incl. uric acid, L-ascorbic acid, glutathione and paracetamol) has been eliminated. The effect of both the temperature and buffer composition on the analytical performance of the sensor has been investigated. Under optimal operational conditions (25°C, −0.05 V vs. Ag/AgCl, phosphate buffer, pH 8.4), the following have been defined for the biosensor: sensitivity 0.39 µA µM−1, strict linearity of the response up to xanthine concentration 70 µM, detection limit of 1.5 µM (S/N=3) and a response time of at most 60 s.

We established, that crystalline hydrate of 2,3:4,5-di-O-isopropylidene-β-D-arabino-hexos-2-ulo-2,6-pyranose is a new, convenient and stable reagent for solid phase synthesis of peptide derived Amadori products. The structure of the title compound was studied by X-ray analysis, NMR spectroscopy, and high resolution ESI-MS. The crystal structure indicated the existence of two symmetry-independent molecules that were not connected with hydrogen bonds. A comparison with previously reported 2,3:4,5-di-O-isopropylidene-β-D-fructopyranose revealed, that these two compounds are isostructural.

Brilliant green was used as a complexing agent in cloud point extraction (CPE) and applied for selective preconcentration of trace amounts of gold in geological matrices. The analyte in the initial aqueous solution was acidified with hydrochloric acid (0.1 M) and octylphenoxypolyethoxyethanol (Triton X-114) was added as a surfactant. After phase separation, based on the cloud point separation of the mixture, the surfactant rich phase was diluted with methanol and the analyte determined in the surfactant rich phase by flame atomic absorption spectrometry (FAAS). After optimization of the complexation and extraction conditions, a preconcentration factor of 31 was obtained for only 10 mL of sample. The analytical curve was linear in the range of 3–1000 ng mL−1 and the limit of detection was 1.5 ng mL−1. The proposed method was applied to the determination of gold in geological samples.

This study describes a technique which makes it possible to introduce the amyloid-like order to protein aggregates by using the scaffolding framework built from supramolecular, fibrillar Congo red structures arranged in an electric field. The electric field was used not only to obtain a uniform orientation of the charged dye fibrils, but also to make the fibrils long, compact and rigid due to the delocalization of pi electrons, which favors ring stacking and, as a consequence, results in an increased tendency to self-assemble. The protein molecules (immunoglobulin L chain lambda, ferritin) attached to this easily adsorbing dye framework assume its ordered structure. The complex precipitating as plate-like fragments shows birefringence in polarized light. The parallel organization of fibrils can be observed with an electron microscope. The dye framework may be removed via reduction with sodium dithionite, leaving the aggregated protein molecules in the ordered state, as confirmed by X-ray diffraction studies.

Attempts have been made to prepare for the first time the octasubstituted-triphenodioxazines and triphenodithiazines heterocycles by cyclisation of 3,6-dichloro-2,5-bis(2′,4′,5′-trichloroanilino)-1,4-benzoquinone and condensation. This wasfollowed by cyclisation of substituted 2-aminobenzenethiol respectively with chloranil and bromanil in ethanolic solution of fused sodium acetate in the presence of benzoyl chloride in nitrobenzene. Their structures were confirmed on the basis of their chemical and spectral analyses. Moreover, the biological activity of these compounds was evaluated against the test organisms viz — E.coli, S. aureus, B. subtilis, M.luteus and C. albicans. These compounds synthesized from 2,4,5-trichloroaniline appeared to possess significant antimicrobial activities and an explicit correlation between structure and biological activity was also observed.

The optimal parameters for ultrasonic treatment (frequency 200–300 kHz, intensity 2–4 W cm−2) were obtained to intensify Pb(II) and Cd(II) sorption concentration by carbon sorbent from apricot pit. The combined action of ultrasonic frequency of 18 kHz and 1 MHz on concentrate slurry increases its sedimentation stability from 3 to 180 minutes and decreases Sr value up to 7% at Pb(II), Cd(II) hybrid sorption atomic absorption determination in natural waters, brines, common salt.

Applying a metathesis approach (MCl2·xH2O+Na2SnO3·xH2O→MSn(OH)6+NaCl+xH2O), Schoenfliesite-type materials with general formula MSn(OH)6 (where M=Ca, Cu, Mg, Mn or Zn) were synthesized at room-temperature. The high lattice-energy of the by-product alkali halide NaCl drives the reaction in the forward direction leading to the formation of the desired materials. The materials synthesized were characterized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) to elucidate structural and micro structural features.

Oxidatively generated damage to DNA frequently appears in the human genome as an effect of aerobic metabolism or as the result of exposure to exogenous oxidizing agents. Due to these facts it was decided to present, for the first time, the electron affinity, ionization potential of 5′,8-cyclo-2′-deoxyadenosine/guanosine (cdA, cdG) in their 5′R and 5′S diastereomeric forms. For all points of quantum mechanics studies presented, the density functional theory (DFT) with B3LYP parameters on 6-311++G** basis set level was used. The zero-point vibrational corrected adiabatic electron affinity (AEA) and adiabatic ionization potential (AIP) were calculated. Additionally the vertical electron affinity (VEA), vertical detachment energy (VDE) and vertical ionization potential were taken into consideration. AEA in eV (gaseous/aqueous phase) are as follows: 0.3/1.81 (5′R)cdA, 0.13/1.76 (5′S)cdA, 0.17/1.49 (5′R)cdG, 0.14/1.53 (5′S)cdG and AIP followed the order 7.43/5.59(5′S)cdG, 7.49/5.60(5′R)cdG, 7.77/5.97(5′R)cdA, 7.84/5.93(5′S)cdA. The obtained AIPs were found to be lower than that for corresponding natural nucleosides. Therefore, even though the 5′,8-cyclopurine-2′-deoxynucleoside level in a cell was judged as low, they can play an important role in the stability, replication and transcription of genes.

A first effort employing a range of polar-group functionalized phosphines (L 1 –L 7 ) to design mononuclear Rh(I) compounds of [Rh(quin-8-O)(CO)(L)] (quin-8-O = 8-hydroxy quinolate) is described. The reaction of a Rh(I) precursor [Rh(μ-Cl)(CO)2]2 with 8-hydroxyquinoline in the presence of a base followed by phosphines (L 1 –L 7 ) produced only a single isomer of [Rh(quin-8-O)(CO)(L)] compounds (1–7) with pendant, i.e. non-bonded, polar-groups (includes carboxyl, hydroxyl and formyl). A relationship between Δgd31P chemical shifts and the ν(C≡O) was derived to evaluate and explain the σ-donor properties of these phosphines with respect to the electronic properties of the polar groups and the extent of π-back-bonding to the CO group. These mononuclear Rh(I)-Phosphines were investigated as catalysts in the hydroformylation of 1-hexene and cyclohexene in aqueous two-phase and single-phase solvent systems. The Rh(I) catalysts with strong σ-donor and hydrophilic phosphines provided better yields and selectivities for the hydroformylation products, which is a reverse trend compared to literature reports. When the Rh(I) compounds contained strong σ-donor phosphines, the π-acceptor properties of the pyridine ring of 8-hydroxyquinolate were found to be beneficial for the facile cleavage of the CO group during hydroformylation, and additionally, to improve the kinetic stability of catalysts.

The analytical method based on the high-performance liquid chromatography coupled with UV detection (HPLC/UV) for determination of selected antioxidants (i.e., esculetin, scopoletin, 7-hydroxycoumarine, rutin, xanthotoxin, 5-methoxypsoralen and quercetin) in plant material was developed. Pressurised fluid extraction (PFE) and ultrasonic extraction (USE) methods for the isolation of these compounds from ten real plant samples were used. Both extraction methods were optimised and compared to each other. For the proposed HPLC/UV method the LOQ values (limit of quantification) in the range from 22.7 (xanthotoxin) to 97.2 ng mL−1 (rutin) were obtained. For all extracts the antioxidant capacity based on the reduction of free 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) was also determined. Results ranged from 82.04 to 94.43% of DPPH radical inhibition for PFE method and from 76.01 to 89.94% in the case of USE method.

Few novel binuclear Schiff base metal complexes [M2LCl3], where M = Cu(II) and Zn(II); L= 2,6-bis-({2-[(3-hydroxy-4-nitrobenzylidene)amino]ethylimino}methyl)-4-methylphenol (BHEM), 2,6-bis-({2-[(3,4-dimethoxybenzylidene)amino]ethylimino} methyl)-4-methylphenol (BDEM) and 2,6-bis-({2-[(2,3,5-trichlorobenzylidene)amino]ethylimino}methyl)-4-methylphenol (BTEM), have been synthesized and characterized by analytical and spectral data. The data suggest that BHEM/BDEM/BTEM ligands afford square-pyramidal/distorted square-pyramidal geometry on metalation with Zn(II)/Cu(II). The binding behaviour of these complexes with DNA has been investigated using electronic absorption spectroscopy as well as viscosity and voltammetric measurements; the results show that they interact with DNA through intercalating way. From the DNA cleavage study of these complexes, investigated by gel electrophoresis, we found that they efficiently cleave supercoiled pUC19 DNA in the presence of a reducing agent (3-mercaptopropionic acid) and on irradiation with UV light of 360 nm wavelength. The mechanism reveals that singlet oxygen (1O2) plays a significant role in the photo cleavage. The superoxide dismutase (SOD) mimetic activity of the synthesized complexes demonstrates that most of the complexes have promising SOD-mimetic activity. The antimicrobial study indicates that the complexes inhibit the growth of bacteria and fungi more than the free ligands.

A new and simple high-performance liquid chromatography method was developed and validated for the simultaneous determination of retinol, retinyl palmitate and β-carotene in rat serum treated with Hypericum Perforatum L. and 7,12-dimethylbenz[a]anthracene. Furthermore, vitamin C was determined spectrophotometrically. High-performance liquid chromatography analysis was performed utilizing an Inertsil ODS3 reversed phase column with methanol-acetonitrile-tetrahydrofuran (65:30:5, v/v/v) as mobile phase, at a flow rate of 1.5 mL min−1 and 40°C. Diode-array detection was conducted at 325 and 450 nm for retinol and retinyl palmitate, and β-carotene, respectively with a running time of 26 min. The high-performance liquid chromatography assay and extraction procedure proposed are simple, rapid, sensitive and accurate. This method was then applied to determine the amounts of retinol, retinyl palmitate and β-carotene in rat serum. Results of this study demonstrated that at 60th day in the 7,12-dimethylbenz[a]anthracene-treated group there was a significant decrease (pa] anthracene + Hypericum Perforatum L. treated group compared to the control group..

Abiotic parameters (pH, temperature, current velocity, mercury species concentration, and sediment and aqueous media composition) influence mercury species (MeHg+, EtHg+, PhHg+ and inorganic Hg2+) adsorption on river sediments. The highest amount of adsorbed MeHg+ and EtHg+ (82–93% and 85–91% for static and agitated system, respectively) occurred at pH 3–4. For PhHg+ the maximum adsorption (90% and 95% for static and agitated systems) was located over the broad 3–10 pH range, while for Hg2+ (94% and 97% for static and agitated systems) it was at pH ∼ 3. Temperature (4.5–60°C) influenced the adsorption rate but not the quantity. Both rate and quantity increased in the order: static 2+ adsorption about 67%. Cations at pH 5.2 reduced either the adsorption rate (Ca2+, Al3+) or the total adsorption (Zn2+, Fe3+). Positive correlations were found between sediment C, N, S content as well as cation exchange capacity (CEC) with mercury adsorption (R = 0.45–0.66, 0.56–0.89, 0.45–0.61 and 0.55–0.73, respectively) while negative correlations were observed with Fe and Al (R = −0.63 to −0.90 and −0.65 to −0.86, respectively).

In this paper we focus on the elastic and thermodynamic properties of the B1 phase of CaO by using the modified TBP model, including the role of temperature. We have successfully obtained the phase transition pressure and volume change at different temperatures. In addition elastic constants and bulk modulus of B1 phase of CaO at different temperatures are discussed. Our results are comparable with the previous ones at high temperatures and pressures. The thermodynamical properties of the B1 phase of CaO are also predicted.

Oxidatively generated damage to DNA frequently appears in the human genome as an effect of aerobic metabolism or as the result of exposure to exogenous oxidizing agents. Due to these facts it has been decided to calculate the stability of 5′,8-cyclo-2′-deoxyadenosine/guanosine (cdA, cdG) in their 5′R and 5′S diastereomeric forms. For all points of quantum mechanics studies presented, the density functional theory (DFT) with B3LYP parameters on 6-311++G** basis set level was used. The calculations showed a significant negative enthalpy for glycosidic bond cleavage reaction for cationic forms and slightly negative for neutral ones. The preliminary study of the discussed process has shown the nature of stepwise nucleophilic substitution DN*AD type mechanism. Surprisingly, the different values in free energy, between short-lived oxacarbenium ion intermediates, have been found to lie over a relatively small range, around 1 and 2.8 kcal mol−1. For anions, the decomposition enthalpies were found as positive in aqueous phases. These theoretical results are supported by the formic acid hydrolysis experiments of both diastereomers of cdA, for the first time. (5′S)cdA exhibited higher stability than (5′R)cdA.

Anatase TiO2 was prepared by sol-gel method through the hydrolysis of TiCl4. Ni2+ was doped into the TiO2 matrix in the concentration range of 0.02 to 0.1 at.% and characterized by various analytical techniques. Powder X-ray diffraction revealed only anatase phase for all the samples, while diffuse reflectance spectral studies indicated a red shift in the band gap absorption to the visible region. The photocatalytic activities of these photocatalysts were probed for the degradation of methyl orange under natural solar light. The photocatalyst with optimum doping of 0.08 at.% Ni2+, showed enhanced activity, which is attributed to: (i) effective separation of charge carriers and (ii) large red shift in the band gap to visible region. The influence of crystallite size and dopant concentration on the charge carrier trapping — recombination dynamics is investigated.

Enriched titanium raw materials with high titanium content called titanium slags are received by the electrothermal reduction of ilmenite. Titanium slags are most frequently used in the titanium dioxide industry. The reaction of titanium slags with sulphuric acid is strongly exothermic and creates danger of thermal explosion. Kinetics of this reaction depends on the parameters such as temperature of initiation, sulphuric acid concentration and dimension of particles of titanium slag. The reaction of titanium slag with sulphuric acid was investigated at non-isothermal conditions in a special construction calorimeter. The observed thermal power changes in the calorimeter (“calorimeter run”), are the basis for estimation of reaction kinetics. A proposed model describing the thermal power changes and taking into account the moment of initiation of reaction is presented. The calorimetric investigations showed, that reaction rate of titanium slags with sulphuric acid depends on initial temperature of reaction, size of particles of titanium raw material and sulphuric acid concentration.

A new chemically modified electrode is constructed based on carbon ceramic electrode incorporated with zeolite ZSM-5. Voltammetric behavior of piroxicam at the carbon ceramic zeolite modified electrode (CCZME) was investigated. The modified electrode exhibited catalytic activity toward the electrooxidation of piroxicam. Experimental parameters such as solution pH, scan rate, concentration of piroxicam and zeolite amount were studied. It has been shown that using the CCZME, piroxicam can be determined by differential pulse voltammetry (DPV) and hydrodynamic amperometry (HA). Under the optimized conditions the calibration plots are linear in the concentration ranges of 0.20–25.00 and 0.20–50.10 μM with limit of detections of 0.65 and 0.29 μM for DPV and HA, respectively. The modified electrode with DPV and HA methods was successfully applied for analysis of piroxicam in pharmaceutical formulations. The results were favorably compared to those obtained by the spiked method. The results of the analysis suggest that the proposed method has promise for the routine determination of piroxicam in the products examined.

A series of N-(6-methylbenzothiazolyl)-2,3,5,6-tetrasubstituted-4-(aryl)-1,4-dihydropyridines were synthesized by reaction of 2-amino-6-methylbenzothiazole, aromatic aldehyde and active methylene compound in methanol by conventional, as well as, microwave irradiation (solvent free and solid support) methods. The microwave irradiation technique gives better yield and shorter reaction time. Among solid supported microwave irradiation better yields are obtained in acidic alumina as compared to silica, neutral alumina, and basic alumina. All compounds were tested for antibacterial and antifungal activities and results have been compared with standard drugs. Entomological activities were also tested. The results showed that a change in the substitution pattern in 1,4-dihydropyridine derivatives may cause a marked effect on their antimicrobial activity.

A series of chalcones and their derivatives have been synthesized. Chalcones, 1-(1,3-benzodioxol-5-yl)-3-(aryl)-prop-2-en-1-ones were prepared by the aldol condensation of 1-(1,3-benzodioxol-5-yl)ethanones and aryl aldehydes. Based-catalyzed condensation of 1-(1,3-benzodioxol-5-yl)-3-(aryl)prop-2-en-1-ones with ethyl acetoacetate yields corresponding ethyl 4-(1,3-benzodioxol-5-yl)-6-(aryl)-2-oxocyclohex-3-ene-1-carboxylates. Some of the synthesized chalcones were reported in the literature; the newly synthesized compounds were characterized by single crystal X-ray studies, IR, 1H-NMR and LCMS mass spectral analysis.

Synthesis of various zirconium doped titania based photocatalysts were carried out by adapting different synthetic strategies. Doping is done on commercially available anatase titania, sol-gel titania and template mediated sol gel titania. A comparative study of the various prepared photocataysts was done using physico-chemical characterization techniques such as X-ray diffraction (XRD), surface area- pore volume measurements, UV-VIS Diffuse reflectance spectra (DRS), elemental analysis (XRF) and transmission electron microscopic (TEM) studies. The effect of zirconium and preparation methods on the photocatalytic degradation of methylorange is studied extensively. Both the surface properties and photo activity of zirconium doped titania were found to have a great dependence on the preparation methods. Among the different photocatalytic systems, the catalyst prepared by doping in the presence of urea template was found to produce a maximum photodegradation of 97.5%.

The efficient conjugate addition of vicinal - OH and - SH acids such as ethylene glycol and 1,2-ethanedithiol to dibenzoylacetylene in the presence of PPh3 leads to different products depending on the reaction conditions. Ab initio calculations at HF/6-31G* level shows that the unsymmetrical envelope conformation of 2,2-disubstituted 1,3-dioxolane 1 is more stable than the half-chair and Cs symmetric envelope forms.

We synthesized nine quaternary ammonium compounds (QUATs) starting from phenylalanine, N-alkyl-N,N-dimethyl-(1-hydroxy-3-phenylpropyl)-2-ammonium bromides, which were prepared as optically pure substances. Five compounds were prepared as S-enantiomers and four compounds as R-enantiomers. These compounds were evaluated by their activities against bacteria and fungi. Three microbial strains were used in the study: the gram-negative bacteria Escherichia coli, the gram-positive bacteria Staphylococcus aureus and the fungi Candida albicans. The activities were expressed as minimum bactericidal or fungicidal concentrations (MBC). The most active compounds were (2S)-N-tetradecyl-N,N-dimethyl-(1-hydroxy-3-phenylpropyl)-2-ammonium bromide and (2R)-N-tetradecyl-N,N-dimethyl-(1-hydroxy-3-phenylpropyl)-2-ammonium bromide, with MBC values exceeding those of commercial benzalkoniumbromide (BAB) used as standard. The relationships between structure and biological activity of the tested QUATs were quantified by the bilinear model (QSAR) and are discussed.

For the first time, various microstructures of calcium phosphates were successfully synthesized using a high internal phase emulsion process. The crystals were possessed in the brushite crystalline phase. The morphology of the crystals was influenced by the variables related to the emulsion process route, which consisted of flakes, dendrites and particulates structures.

The multivariate calibration methods, partial least squares (PLS) and principle component regression (PCR) have been used to determine phenanthridine, phenanthridinone and phenanthridine N-oxide in spiked human plasma samples. Resolution of binary and ternary mixtures of analytes with minimum sample pre-treatment and without analyte separation has been successfully achieved analyzing the UV spectral data. The net analyte signal (NAS) concept was also used to calculate multivariate analytical figures of merit such as limit of detection, selectivity and sensitivity. The simultaneous determination of three analytes was possible by PLS and PCR processing of sample absorbance in the 210–355 nm region. Good recoveries were obtained for both synthetic mixtures and spiked human plasma samples.

The present study was undertaken to develop a novel adsorbent for heavy metal ions, and this paper presents the synthesis and characterization of a composite material-silica gel microspheres encapsulated by salicyclic acid functionalized polystyrene (SG-PS-azo-SA) with a core-shell structure. SG-PS-azo-SA was used to investigate the adsorption of Mn(II), Co(II), Ni(II), Fe(III), Hg(II), Zn(II), Cd(II), Cr(VI), Pd(II), Cu(II), Ag(I), and Au(III) from aqueous solutions. The results revealed that SG-PS-azo-SA has better adsorption capacity for Cu(II), Ag(I) and Au(III). Langmuir and Freundlich isotherm models were applied to analyze the experimental data, the best interpretation for the experimental data was given by the Langmuir isotherm equation with the maximum adsorption capacity for Cu(II), Ag(I), and Au(III) at 1.288 mmol g−1, 1.850 mmol g−1 and 1.613 mmol gt-1, respectively. Thus, silica gel encapsulated by salicyclic acid functionalized polystyrene (SG-PS-azo-SA) is favorable and useful for the removal of Cu(II), Ag(I) and Au(III) metal ions.

The mechanism of the dirhodium tetracarboxylate-catalyzed O-H insertion reaction of diazomethane and methyl diazoacetate with H2O has been studied in detail using DFT calculations. The rhodium catalyst and a diazo compound couple to form a rhodiumcarbene complex. Of two reaction pathways of the Rh(II)-carbene complex with H2O, the stepwise pathway is more preferable than the concerted one. Formation of a Rh(II) complex-associated oxonium ylide is an exothermal process, and direct decomposition of the ylide gives a very high barrier. The high barriers for the 1,2-H shift of Rh(II) complex-associated oxonium ylides make the ylides become stable intermediates in both reactions, especially for the reactions in solution. Difficulty in formation of a free oxonium ylide supports experimental results, indicating that the Rh(II) complex-catalyzed nucleophilic addition of a diazo compound proceeds via a Rh(II) complex-associated oxonium ylide rather than via a free oxonium ylide.

A series of new hexa-coordinated ruthenium(II) complexes of the type [Ru(CO)(EPh3)(B)(L)] (E = P or As; B = PPh3, AsPh3 or Py; L = chalcone thiosemicarbazone) have been prepared by reacting [RuHCl(CO)(EPh3)2(B)] (E = P or As; B = PPh3, AsPh3 or Py) with chalcone thiosemicarbazones in benzene under reflux. The new complexes have been characterized by analytical and spectroscopic (IR, UV-vis, 1H, 31P and 13C NMR) methods. On the basis of data obtained, an octahedral structure was assigned for all of the complexes. The chalcone thiosemicarbazones behave as dianionic tridentate O, N, S donors and coordinate to ruthenium via the phenolic oxygen of chalcone, the imine nitrogen of thiosemicarbazone and thienol sulfur. The new complexes exhibit catalytic activity for the oxidation of primary and secondary alcohols to their corresponding aldehydes and ketones and they were also found to be efficient catalysts for the transfer hydrogenation of carbonyl compounds.

The original version of the article was published in Central European Journal of Chemistry, 2008, 7(4), 870–875, DOI: 10.2478/s11532-009-0091-2. Unfortunately, the original version of this article contains mistakes in the date section. There should be: received 13 February 2009, accepted 24 May 2009.