bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mise En Evidence Par Rmn‐1H Et ‐13C D'Isomerisme Z/E Et D'Equilibre Conformationnel Sur Une Serie De Derives Mono‐ Et Diacetyles De 2‐Alkylamino‐1‐Phenylpropan‐1‐Ols
Authors: Tytgat D. , Gelbcke M. 
Published: September 2010

Abstract1H‐ and 13C‐NMR studies of mono‐ and diacetylated‐erythro‐ and threo‐2‐alkylamino‐1‐phenylpropan‐1‐ols, C6H5CHOHCHNHRCH3 (R = H, CH3, C2H5 and i‐C3H7) show that the series exhibit Z/E isomerism about the C‐N amide bond. The Z/E ratio increases in the monoacetylated series CH3 < C2H5 < i‐C3H7 indicating that the hydrogen bond between the hydroxylic proton and the carbonyl function of the amide is in the case of the isopropyl substituent favoured. In the diacetylated series, where an hydrogen bond is not possible, the Z/E ratio is respectively in the erythro and threo series about 3 and 1. The progressive increase of the volume of the substituent N‐alkyl modifies the conformational equilibrium about the C1‐C2 and N‐C2 bonds. In the Z configuration, the conformer Z‐s‐syn where the proton H‐2 is syn with the N‐alkyl substituent predominates.
Novel Syntheses of Heterocycles with N‐(1‐Haloalkyl)Azinium Halides. Part 3. Preparation of 2‐Aryl‐1‐Arylimino‐2,3‐Dihydro‐1H‐Isoindoles
Authors: Vanden Eynde J.‐J. , Mayence A. , Maquestiau A. , Anders E. 
Published: September 2010

AbstractThe title compounds can be synthesized readily by reaction of primary aromatic amines with the azinium salt obtained from thionyl chloride, pyridine, and 1,2‐benzenedicarboxaldehyde.
New Low Coordination Phosphorus Heterocycles
Authors: Teunissen Herman T. , Bickelhaupt Friedrich 
Published: September 2010

AbstractWith the aim of synthesizing novel functionalized derivatives of phosphinine (phosphabenzene), we investigated Diels‐Alder approaches to 2‐halophosphinines. The reaction of dienes such as 1‐isopropenyl‐1‐cyclohexene and 1‐vinylnaphthalene with Cl2P‐CHCl2 and triethylamine gave 2‐chlorophosphinines, but their substitution pattern was unsuitable for the synthesis of bidentate phosphinine ligands. However, the precursor Cl2P‐CHl2 reacted with triethylamine in the presence of 1,3‐butadiene or its 2,3‐dimethyl derivative to furnish 2‐iodophosphinines 5 which, directly or after formation of their pentacarbonyltungsten complexes, underwent a number of interesting functionalization reactions. Useful for reaction with a number of electrophiles were the organozinc reagent 4,5‐dimethyl‐2‐iodozincophosphinine (26) which could be obtained directly from the corresponding 2‐iodophosphinine 5b and zinc either in DMF or in THF/TMEDA, and the pentacarbonyltungsten coordinated 2‐lithio derivative 36.
Novel Reactions of Carbohydrates Discovered En Route to Natural Products
Authors: Fraser‐Reid B. , Alonso R. A. , McDevitt R. E. , Venkateswara Rao B. , Vite G. D. , Zottola M. A. 
Published: September 2010

AbstractAn approach to the synthesis of tetrodotoxin is described in which two key reactions are used to establish the densely functionalized carbocyclic ring. The [3:2:1]‐bicyclic framework of 1,6‐anhydro mannopyranose serves as the template, and in the first key reaction, oxazolidine ring formation is used to introduce the angular nitrogen and, simultaneously, to preorganize functional groups for the second key reaction. The latter involves formation of the carbocyclic ring via a radical cyclization process.
Electrochemical Study of CIS‐Dicyanoaquoethylenediamine Nitrosylchromium Complex and its Adducts with Mercury(II) and Silver(I)
Authors: Rievaj Miroslav , Korgová Elena , Bustin Dusan 
Published: September 2010

AbstractThe paper describes electrochemical properties of NO(en)(H2O)Cr(CN)2 and the polarographic investigation of its acid hydrolysis. Stoichiometry (1:1) of NO(en)(H2O)Cr(CN)2 reactions with Hg2+ and Ag+ was determined using potentiometric method. Adducts formed by these reactions were investigated polarographically and linkage isomerisation of bridging cyano ligands has been found to be involved in their formation. Decomposition kinetics of the adduct NO(en)(H2O)Cr(NC)2Hg2+ was studied, factors affecting it discussed and found kinetics data compared with those determined for similar cyano complexes.
Crystal Structure of 1,3,5(10)‐Estratriene‐1,17 β‐Diol 17‐Acetate
Authors: Tinant B. , Declercq J. P. , Rajkovic M. , Petrovic‐Davidovic I. , Lorenc Lj. , Mihailovic M. Lj. 
Published: September 2010

AbstractOxidative hydrolysis of N‐methyl‐1β, 5‐epoxyimino‐19‐nor‐5β‐androst‐3‐en‐17β‐ol acetate 1 afforded the title compound 2, the molecular structure of which was determined by the X‐ray diffraction technique. 2 : C20H26O3, Mr=314.42, orthorhombic, P212121, a=9.636(3), b=11.307(5), c=16.096(5)Å, V=1754(1)Å3, Z=4, Dx=1.19g.cm−3, MoKα, λ=0.71069Å, μ=0.84cm−1, F(000)=680, T=291K, R=0.060 for 1211 observed reflections. Ring A is slightly non planar, ring B is a half‐chair and ring C a chair. The 5‐membered ring D has a regular half‐chair conformation.
Another Possible Carbon Allotrope
Authors: Elguero José , Foces‐Foces Concepción , Llamas‐Saiz Antonio L. 
Published: September 2010

AbstractA new allotropic form of carbon formed by allene units is described. Its tetragonal unit cell contains 12 carbon atoms (8 sp2 and 4 sp) and it has a calculated density of 2.72 g. cm−3. As a result of the mixture of sp2 and sp carbon atoms, this new all‐carbon molecule is expected to be rather stable and may have metallic properties.
On the Mechanism of Selective Chlorination of Ethers with Sulfuryl Chloride in the Dark
Authors: De Buyck Laurent , De Pooter Herman 
Published: September 2010

AbstractAlkyl 4‐chlorobutyl ethers reacted in the dark with an excess of sulfuryl chloride at 70–85°C (bath) to afford α,β,β‐trichlorinated ethers. The reactions were accelerated 3− to 6‐fold by N,N‐dimethyl‐octylammonium salts (0,12 to 1 mmol/mol ether). This catalyst promoted decomposition of sulfuryl chloride to chlorine and sulfur dioxide and thereby caused serious loss of sulfuryl chloride. The proportions of chlorination at α or α' position were identical in the catalyzed or uncatalyzed version and depended on inductive effects, correlating well with Taft's linear free energy relationship log k/kref = ρ* σ* for R = H, Me, Et, Pr in RCH2O(CH2)4Cl with ρ* = −2.6±0.1. The overall reactivity of ethers appears to vary like the nucleophilicity of the ether oxygen. It is concluded that hydride abstraction occurs indirectly, probably involving a chloroxonium ion pair.
A Convenient Preparation of Pivalaldehyde: Some Remarks on the Bouveault Synthesis
Authors: Nazarski Ryszard B. , Tasz Maciej K. , Skowroński Romuald 
Published: September 2010

AbstractA simple and versatile procedure of pivalaldehyde synthesis is described. The synthesis is based on the formylation of tert‐butyl magnesium chloride with excess of DMF in low temperature and can be easily performed in bulk scale. The application of DMF for the formylation of tertiary Grignard compounds is briefly discussed in terms of steric effects.
Effet Hall Hyperfréquence Dans Des Semi‐Conducteurs Constituant Des Jonctions
Authors: Ammari M. , Gire A. , Lomaglio Mme G. , Théobald J. G. 
Published: September 2010

AbstractThe resonances at microwave frequencies can be observed in polarized junctions; this was studied in previous papers and we have called for an important contribution of minority carriers. With a magnetic field B, a non diagonal component of the electrical conductivity can exist, a sort of microwave Hall effect. This can be considered as the effect of the non‐diagonal part of the microwave susceptibility along the E ⁁ B direction. We report the observation of this non‐diagonal component, which allows to verify the sign of the charge carriers. This experiment can be considered as a generalization of the d.c. Hall effect.
A Fast Method for Fitting the G Tensor of EPR Powder Spectra Using the Levenberg‐Marquardt Algorithm
Authors: Moens P. D. W. , Naessens D. E. , Callens F. J. , Matthys P. F. A. , Maes F. R. C. , Boesman E. R. 
Published: September 2010

AbstractA finite difference Levenberg‐Marquardt algorithm is used for optimizing the principal g tensor values of paramagnetic radicals observed in EPR spectra of polycrystalline materials. A special method is presented to select a small number of data points which are assumed to be representative for the entire EPR powder spectrum. Thus, the spectrum has only to be calculated in a small number of points resulting in a drastic reduction of the computer time. The method is demonstrated on two simulated EPR powder spectra and one experimentally recorded spectrum of X‐irradiated powdered human tooth enamel.
Basicite De L'Hydroxyde De Tetrabutylammonium En Milieu Acetonitrile Eau
Authors: Borghese A. , Laurent F. , Tondeur J.‐J. , Vandendunghen G. 
Published: September 2010

AbstractThe acidity function H. of tetrabutylammonium hydroxide in aqueous acetonitrile has been evaluated by use of Hammett indicators in the range of molar fractions in water lying between 0.05 and 0.65. The results are correlated with the available data concerning the structure of these mixtures.
Synthese Und Antitumoraktivität Von Platin(II)‐Komplexen Mit Cholesterinderivaten
Authors: Brunner H. , Sperl G. 
Published: September 2010

AbstractLow‐density‐lipoprotein‐receptor binding moieties were introduced into Pt(II) complexes in order to facilitate the selective transport into cancer cells. Cholesterol esters of aminoacids and 2,3‐diaminopropionic acid were attached to the PtCl2 fragment via their NH2 groups. Steroidal amine and diamine ligands were synthesized and transformed into the corresponding dichloroplatinum(II) complexes. A steroidal carboxylic acid was prepared and coupled with the Pt(NH3)2 fragment. The antitumor activity of the compounds was tested towards the lymphatic P 388 leukemia of the CD2F1 mouse and towards the human mammary carcinoma cell line MDA‐MB 231. The Pt(II) complexes gave a maximum growth inhibition of 54%.
A Theoretical (AM1) and Experimental Dipole Moment Study of 5(4H)‐Oxazolones
Authors: Cativiela C. , Díaz De Villegas M. D. , Fayet J. P. , García J. I. , Mayoral J. A. , Vertut M. C. 
Published: September 2010

AbstractExperimental and calculated (AM1) dipole moments have been determined for a series of Z and E‐isomers of 4‐phenylmethylene‐5(4H)‐oxazolones (1) and 4(α‐phenylethylidene)‐5(4H)‐oxazolones (2) in order to study the conformation in solution of the phenyl group in position 4. The comparison between experimental and calculated values for the Z‐isomers indicates a planar conformation of the phenyl group. In the case of E‐isomers the agreement is good for IE, which is probably planar, but not so good for 2E, although the perpendicular form shows better agreement. These results have been confirmed by 1H‐NMR.
The Molecular Structure of the Steroidal Isoxazolidine Products Derived from (Z)‐3β,17β‐Diacetoxy‐19‐NOR‐5,10‐Secoandrost‐1(10)‐En‐5‐One
Authors: Tinant B. , Declercq J. P. , Lorenc L.J. , Rajkovic M. , Milovanovic A. , Mihailovic M. Lj. 
Published: September 2010

AbstractX‐Ray analysis of the steroidal isoxazolidine derivatives 2 and 3b, which are formed (the latter as the corresponding diacetate 3a) in the reaction of (Z)‐3β,17β‐diacetoxy‐19‐nor‐5,10‐secoandrost‐1(10)‐en‐5‐one (1) with N‐methylhydroxylamine, has revealed that both compounds (and therefore also 3a) have the same cis‐1β, 5β‐epoxyimino bridge structure. The conformations of the two molecular skeletons are compared.
Lifetime of the Triplet State of Methylene Blue in the Presence of Salicylic Acid
Authors: Sedlák Petr , Vidóczy Tamás , Luňák Stanislav 
Published: September 2010

AbstractA break the lifetime of MBH2+ (T1) vs. salicylic acid concentration plot occurs at around 6 × 10 E(‐5) M (corresponding to pH of the solution 4.3). This pH is close to pK1 of leucomethylene blue. The quantum yields of 2,3‐dihydroxybenzoic acid increase with increasing salicylic acid concentration over the whole range investigated (9 × 10 E(‐6) ‐ 3 × 10 E(‐4)M); the growth of the quantum yields becomes more pronounced for pH < 4.35, too.
Catalytic Spectrophotometric Determination of Ruthenium by Flow Injection Analysis Using Amido Black 10B and KIO4
Authors: Xingguo Chen , Zhide Hu , Hongwen Zheng 
Published: September 2010

AbstractA new method has been developed for the determination of trace ruthenium by flow injection analysis. The proposed method is rapid, simple and sensitive. The method has a limit of detection for ruthenium of 0.050 μg/mL and permits 60 determinations per hour. The method has been applied to determine ruthenium in refined ore with satisfactory results.
Determination Bioelectrocatalytique Du Glucose En Presence D'Autres Glucides. Specificite Du Dosage
Authors: Stoytcheva Margarita 
Published: September 2010

AbstractThe specificity of the bioelectrocatalytical glucose determination with a chronoamperometric detection was tested. It was demonstrated that the high specificity of the enzymatic methods was conserved and the glucose analysis can be accomplished in presence of galactose, maltose, fructose and saccharose.
Bridge Flipping Data from Dynamic 1H‐NMR Spectra of 2,6‐Dimethyl‐[9](3,5)‐Pyridophane and its Pyrylium and N‐Methylpyridinium Analogs
Authors: Balaban Alexandru T. , Balaban Teodor‐Silviu , Nitta Makoto , Kanomata Nobuhiro 
Published: September 2010

AbstractDynamic 1H‐NMR spectra between room temperature and −90 °C for the title compounds indicate that the flipping of the nonamethylene bridge is slowed down on cooling (ΔGc‡ = 9.8 kcal/mol for the 2/8 methylene groups in the pyridinophane with coalescence temperature Tc = −58 °C) but the pseudorotation persists even at −90 °C. The bridge flipping is somewhat easier in the N‐methylpyridinium (ΔGc‡ = 9.7 kcal/mol, Tc = −63 °C) and in the pyrylophanium perchlorates (ΔGc‡ = 8.9 kcal/mol, Tc = −78 °C).
Synthesis of Pyridine Containing Macrocyclic Schiff Bases and Their Corresponding Polyamines
Authors: Dhont K. I. , Lippens W. , Herman G. , Goeminne A. M. 
Published: September 2010

AbstractThree macrocyclic Schiff bases have been synthesized by [2+2] condensation of 2,6‐pyridinedicarbaldehyde with 1,4,7‐triazaheptane, 1,5,9‐triazanonane and 1,5‐diazapentane. Another Schiff base was synthesized by [1+1] condensation of the dicarbaldehyde with 1,5,9‐triazanonane. They were reduced with NaBH4 of the corresponding saturated octaaza, hexaaza and tetraaza polyamines.
EPR, XPS and Spectra Studies of Some 3D Complexes with Salicylidene‐Benzol Hydrazide
Authors: Bo Wang , Dianzhong Feng 
Published: September 2010

AbstractStudies of transition metal complexes with salicylidene‐aroyl hydrazide Schiff base have been subject of many investigations (1,2). In this communication we present the synthesis, EPR, XPS, electronic and vibrational spectra of Co(II), Ni(II), Cu(II), Mn(II) and Zn(II) complexes with salicylidene‐3‐nitrobenzoyl hydrazide Schiff base (HL) ligand.
Calculation of Dipole Strengths for Magnetic Dipole Transitions in Lanthanide Spectra
Authors: Görller‐Walrand C. , Fluyt L. , Verhoeven P. , Berghmans E. , Vandenberghe G. M. 
Published: September 2010

AbstractThe quantitative treatment of intensities of lanthanide spectra has been the subject of several papers [1],[2],[3],[4],[5]. However due to the kind of samples used or to the type of polarisation of the light, some subtle differences in the expressions relating calculated and experimental values appear to be very misleading for the interpretation of the results. It is thought that subsequent papers could gain in clarification by using Table 1., derived in this paper.
Étude du Mécanisme de La Réaction D'Hydrocondensation D'Oxydes de Carbone
Authors: Ghazi M. , Barrault J. 
Published: September 2010

AbstractIn this work, a reaction mechanism for oxides hydrocondensation of carbon monoxide on nickel‐molybdenum catalyst is proposed. The formation of higher alcohols may occur by a CO insertion into a growing carbon‐carbon chain whereas methanol may be formed from CO via formyl or formate species.Hydrocarbon formation may result from superficial “CHx” species hydrogenation.
Influence de L'Acidité du Milieu Électrolytique Sur Les Caractéristiques Électrochimiques de Nouvelles Électrodes a La Bromanile
Authors: Fall M. , Dieng M. M. , Bonora Pi. , Aaron J. J. 
Published: September 2010

AbstractThe properties of solid electrodes constituted of a mixture of bromanil and acetylen black have been investigated. The influence of the acidity of the electrolytic medium (sulfuric acid) on the electrochemical characteristics of bromanil in the solid state has been studied by galvanostatic and chronopotentiostatic methods.
Synthesis and HPLC Separation of 6‐Fluoro‐L‐Dopa Metabolites
Authors: Luxen A. , Monclus M. , Hendrickx P.‐Y. , Masson C. , Melega W. P. 
Published: September 2010

AbstractThe synthesis of 6‐fluoro‐L‐dopa metabolites (3‐O‐methyl‐6‐fluorodopa (1b), 6‐fluorodopamine (2a), 3‐O‐methyl‐6‐fluorodopamine (2b), 3,4‐dihydroxy‐6‐fluorophenylacetic acid (3a) and 6‐fluorohomovanillic acid (3b)) is described. A HPLC method for their separation is also presented.
Determination of Some 1,4‐Benzodiazepines by Oxidative Coupling of their Acid‐Induced Degradation Products
Authors: El‐Yazbi Fawzy A. , Galal Shereen M. , Blaih Salah M. 
Published: September 2010

AbstractThe oxidative coupling reaction of 3‐methylbenzothiazolone hydrazone with aromatic amines was applied to the determination of five 1,4‐benzodiazepine derivatives. The drugs were first hydrolyzed in acid medium and the liberated benzophenone derivatives were reacted with the chromogenic reagent in the presence of cerric ammonium sulphate to give a pink color. A linear correlation was found between the absorbance at λmax and concentration. The method was applied to the determination of these drugs in bulk powder and in pharmaceutical preparations. The procedure was extended to develop a stability‐indicating method for these drugs.
Computer‐Assisted Investigation of Possible Rearrangements of (Ch)N (N = 4,6,8,10) Annulenes
Authors: Atovmyan Igor L. , Shcherbukhin Vladimir V. , Zefirov Nikolai S. 
Published: September 2010

AbstractApplication of the computer program for the rationalization and prediction of possible rearrangements in annulenes with the common formula (CH)n (n = 4‐10) is considered. Processes of [2+2]‐, [2+2+2]‐, [4+2]‐cycloaddition and [4]‐, [6]‐ electrocyclic reactions in the families of annulenes are discussed. A list of all possible reactions proceeding as [1,3]‐, [1,5]‐, [3,3]‐sigmatropic shifts in cyclopolyene structures is presented. The whole set of known annulene reactions is reproduced. A wide set of prospective rearrangements is predicted, including several interesting examples of the degenerate Cope rearrangement.
Nouveaux Décontaminants. Destruction Chimique du Paraoxon Et du Parathion au Moyen de Composés a Chlore Positif
Authors: Hedayatullah Mir , Lion Claude , Tourki Amel 
Published: September 2010

AbstractThe use of compounds possessing positive chlorine and precursors of hypochlorite anions, with different micellar systems, permits the very rapid and complete destruction of paraoxon and parathion taken as models of insecticides or potent chemical warfare agents. Their optimized half‐lives are respectively 49 and 142 seconds.
Determination of Mo(VI) with 2‐Indolehydroxamic Acid by Differential Pulse Polarography and Cathodic Stripping Voltammetry
Authors: Valiente P. , Jimenez M. , Sanchez A. , Lopez‐Arza V. , Rodriguez J. 
Published: September 2010

AbstractIn this paper, the polarographic reduction of 2‐IHA and its Mo(VI)‐2‐IHA complex by differential pulse polarographic and by cathodic stripping voltammetry are shown. Very low detection limits have been achieved using cathodic stripping voltammetry to determine this method.
Influence de La Nature du Solvant Sur La Dépendance du Volume Molaire Et de La Conductivité des Solutions D'Électrolytes Vis‐A‐Vis De Leur Concentration
Authors: Claes P. , Mestdagh C. , Glibert J. 
Published: September 2010

AbstractThe systems investigated in this work are composed of the ternary eutectic mixture NH4NO3‐NH4Cl‐LiNO3 (66.7:9.5:25.8 mol. %) on the one hand and of ethylene‐glycol, formamide, dimethylformamide or dimethylsulfoxide on the other hand. The influence of the composition of these mixtures on their molar volume and on the electrical conductivity has been evidenced. At high electrolyte concentration, the composition dependence of the molar volume is explained by the exclusive localisation of the molecular compound in the solvation shell of the ions. The comparison of the conductivity isotherms points out the influence exercised by the dimensions and by the shape of the molecules of the non‐electrolyte on the ionic mobilities.
Medium Effect on the Base‐Catalysed Hydrolysis of Substituted Triphenylsilanes in Acetonitrile
Authors: Tondeur J.‐J. , Vandendunghen G. , Borghese A. 
Published: September 2010

AbstractThe hydrolysis of some p‐substituted triphenylsilanes in the presence of tetrabutyl‐ammonium hydroxide has been investigated in various water‐acetonitrile media with the aim of comparing the results with those already published for triphenylsilane. It appears that the initial rate is first order with respect to both silane and base whereas the order during the time is not constant for some silanes, depending on the water composition. The second order rate constant varies in agreement with the Hammett substituent constant σp. From the calculations of the transfer Gibbs functions for the activated state and for OH− from a reference medium (water mole fraction = 0.225), it is concluded that the solvent effect is not fundamentally altered by the p‐substituents and that the medium influence on the rate can be essentially attributed to solvation modifications around OH−.
Molecular Structure Analysis of Moclobemide, a Monoamine Oxidase Inhibitor
Authors: Wouters J. , Moureau F. , Norberg B. , Evrard G. , Durant F. 
Published: September 2010

AbstractThe crystal structure of Moclobemide,p‐chloro‐N‐(2 morpholinoethyl) benzamide is reported and compared with that of Moclobemide hydrochloride monohydrate. There is free rotation of the phenyl ring and the amidic function of the benzamide moeity as confirmed by a conformation analysis performed with the PCILO “Perturbative Conformation Interaction using Localized Orbitals” method. C13H17N2O2Cl, Mw=268.4, primitif, P‐1, a=11.569(3), b=13.814(4)Å, C10.004(2), α=98.27(2), β=113.87(2), γ=104.13(2)°, V=1363.7Å3, Z=2, DC1.31 g·cm−3, Mo Kα, λ=0.71060Å, μ=2.32 cm−1, F(000)=568.0, T=293 K, final Rw=0.080 for 2995 observed reflections (I≥2 σ(I)).
3′‐5′ Cyclic Oligothymidylic Acids: Conformation and Complexation of Intercalating Agents
Authors: Hamoir G. , Sonveaux E. 
Published: September 2010

AbstractThe cyclic oligonucleotides c‐(TpTp) 4a, c‐(TpTpTp) 4b and c‐[(3‐Me)Tp(3‐Me)Tp] 4c were synthesized. Their conformations were studied by NMR (500 MHz) and CD spectroscopies. The association constants of proflavine and ethidium bromide with 4a and 4b were determined.
Selective Hydrogenation of Styrene on Pd‐Ho/γAl2O3 and Pd/γAl2O3 Catalysts
Authors: Pârvulescu V. I. , Pârvulescu V. , Frunza L. , Grecu N. , Enache C. , Angelescu Em. 
Published: September 2010

AbstractPd‐Ho/γAl2O3 catalysts exhibit higher activity for styrene hydrogenation than Pd/γAl2O3 ones. The addition of holmium to Pd catalysts changes the place of the palladium impregnation front depending on the state of the supported palladium. As a consequence of the interaction between holmium and Pd/γAl2O3 support, oxidized forms as holmium aluminate were formed. These forms are catalytically inactive but represent adsorption centers for styrene. On holmium containing catalysts, hydrogenation takes place between the styrene adsorbed on basic centers and the hydrogen spilled over from palladium particles.