bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Polysurface Mechanism of Ta and Ti Anodic Dissolution in Low-Temperature Carbamide-NH4CL Melt
Authors: Volkov S. , Tumanova N. , Kothetova S. , Buryak N. 
Published: February 2015

Abstract
In this work the peculiarities of the electrochemical dissolution of tantalum and titanium in carbamide containing low temperature melts were studied.
Structural Investigation of Vanadium-Sodium Metaphosphate Glasses
Authors: Chrissanthopoulos A. , Pouchan C. , Papatheodorou G. N. 
Published: February 2015

Abstract
Paper presented a t the NATO A dvanced Study Institute, May 4-1 4 , 2001 (Kas, Turkey) The structure of the glass forming system (V2O5)x -(Na2O • P2O5)(1-x), (x = 0-0.4), has been inves­ tigated using Raman spectroscopy. The stretching vibrations of various phosphate groups, connected to phosphorus or vanadium atoms, have been assigned. Variation of the composition leads to structural changes where the sodium metaphosphate -P-O-P-chains break and then reconnect with the oxovana-dium units forming a -V-O-P-network structure.
A Dielectric Relaxation Study of Diethylsulfoxide/ Tetrachloromethane Binary Mixtures
Authors: Markarian S. A. , Galstian A. S. , Stockhausen M. 
Published: February 2015

Abstract
The dielectric spectra of diethylsulfoxide (DESO)/tetrachloromethane mixtures have been measured from 0.5 to 72 GHz at 20 °C. On the basis of the relation between the relaxation time and the DESO concentration a complex formation between DESO and tetrachloromethane is suggested.
Abundant New Exact Solutions of the Coupled Potential KdV Equation and the Modified KdV-Type Equation
Authors: Yan Zhenya 
Published: February 2015

Abstract
Exact solutions of nonlinear evolution equations (NLEEs)in soliton theory and their applications are studied. A powerful method is established to search for exact travelling wave solutions of NLEEs. We chose the coupled potential KdV equation and modified KdV-type equations presented by Foursov to illustrate the approach with the aid of Maple. As a result, eight families of exact solutions of the coupled potential KdV equation and nine families of exact solutions of the modified KdV-type equations are obtained, which contain new kink-like soliton solutions, kink­ shaped solitons, bell-shaped solitons, periodic solutions, rational solutions and singular solitons. The properties of the solutions are shown in figures.
Abundant New Multiple Soliton-like Solutions and Rational Solutions of the (2+1)-Dimensional Broer-Kaup Equation
Authors: Yan Zhenya 
Published: February 2015

Abstract
In this paper we firstly improve the homogeneous balance method due to Wang, which was only used to obtain single soliton solutions of nonlinear evolution equations, and apply it to (2 + 1)-dimensional Broer-Kaup (BK) equations such that a Backlund transformation is found again. Considering further the obtained Backlund transformation, the relations are deduced among BK equations, well-known Burgers equations and linear heat equations. Finally, abundant multiple soliton-like solutions and infinite rational solutions are obtained from the relations.
Molecular Conformation and Structural Correlations of Liquid D-tert-Butanol at Room Temperature by Neutron Diffraction
Authors: Nath P. P. , Sarkar S. , Krishna P. S. R. , Joarder R. N. 
Published: February 2015

Abstract
An analysis of neutron diffraction data of liquid deuterated terr-butanol at room temperature to determine its molecular conformation is presented. Being a big molecule of 15 sites, the analysis is tricky and needs careful consideration. The resulting molecular parameters are compared with those obtained from other experimental data analysis and model calculations. The information about the intermolecular structural correlations, hydrogen-bonded molecular association in particular is also obtained from the diffraction data analysis. -PACS number: 61.25
Studies of Zero-field Splitting and its Pressure and Stress Dependence for Ni2+ in La2Mg3(NO3)12 · 24 H2O Crystal
Authors: Zheng Wen-Chen , Wu Shao-Yi , Dong Hui-Ning 
Published: February 2015

Abstract
By using the high-order perturbation formulas, the g factors g||
and g⊥, the zero-field splittings D and the pressure and uniaxial stress dependences of zero-field splitting are studied for Ni2+ ions in both Mg + sites of La2Mg3(NO3)12 • 24 H2O crystal. It is found that the local trigonal distortion angles ßi
of the two Ni + centers are only slightly different from the corresponding host ones, but the local angular compressibilities under pressure and stress for both Ni centers are quite different not only from the corresponding host ones, but also from each other.
The Influence of the Degree of Organization of Saturated Solutions on the Shape of the Solubility Isotherm
Authors: Eysseltová Jitka , Ebert Miroslav , Zbranek Vladimír 
Published: February 2015

Abstract
Special features of solubility isotherms of salt hydrates have been observed, from which the evidence of strong organization of saturated solutions of hydrates may be deduced. Often observed low contents of the non saturating component in the eutonic solution limiting the crystallization branch of hydrated salts is put into connection with this result. The composition of the respective eutonic solutions exhibits a correlation with the hydration entropy of the ions present in the ternary saturated solution.
Universal Scaling of Alpha Relaxation in Complex Liquids
Authors: Kurbatov A. , Drozd-Rzoska A. , Rzoska S. J. , Paluch M. , Malik P. , Zioło J. , Jadżyn J. 
Published: February 2015

Abstract
A plot is given, showing the result of a scaling analysis of dielectric loss curves containing, apart from low molecular glass former data (glycerol, dibutyl phtalate), also loss curves of the following liquid crystalline materials, mostly in the iso­ tropic phase: 4-(2-methylbutyl)-4'cyanobiphenyl (5*CB, supercooled isotropic phase), 4-cyano-4-n-alkyl biphenyls (nematogens 5CB and 8CB, isotropic phase), 4-(4-cyano-4-butylcyclohexyl)-4'-octylbiphenyl (laterally substituted nema-togen, isotropic phase), and 4-n-alkyl-4'-isothiocyanatobiphe-nyl (5 and 10 BT, isotropic and SmE phases). The plot applies the scaling formula originally proposed for glassforming, super­ cooled liquids [Dendzik et al.7]. The result supports the recent suggestion that dielectric relaxation in the isotropic phase of nematogens may show some features typical for "glassy" mate­ rials.
Insertionen in die Molybdän-Kohlenstoff-Bindung von η7-C7H7Mo(CO)2R-Spezies (R = CH3, C6H5); Darstellung und Charakterisierung von EO2 (E = S, Se, Te)- und Zn-Einschiebungsprodukten / Insertions into the Motybdenum-Carbon Bond of η7-C7H7Mo(CO)2R Species (R = CH3, C6H5) ; Synthesis and Characterization of EO2 (E = S, Se, Te) Insertion Products
Authors: Dell Winfried H. , Ziegler Manfred L. 
Published: February 2015

Abstract
The compounds η7-C7H7Mo(CO)2R (R = CH3, C6H5) were synthesized and characterized. The SO2-insertion into the Mo-C bond of the methyl and phenyl species was accomplished by condensing dry SO2 into the ether solutions of the compounds. The SeO2 and TeO2 insertion was only successful with the methyl compound activating the dioxides in a metal vapour apparatus. There is strong evidence that Zn can also be inserted in the Mo-C bond of η7-C7H7MO(CO)2CH3.
Darstellung und Charakterisierung von dreifach NR2-verbrückten Molybdänkomplexen des Typs η3-C7H7(CO)2Mo(μ–NR2)3Mo-η7-C7H7 / Synthesis and Characterization of Triply NR2-Bridged Molybdenum Complexes of the Type η3-C7H7(CO)2Mo(μ-NR2)3Mo-η7-C7H7
Authors: Dell Winfried , Ziegler Manfred L. 
Published: February 2015

Abstract
The mixed-valence compounds of composition C7H7(CO)2Mo(μ-NR2)3MoC7H7 (R=H, p-NO2-C6H4, C4H4) can be synthesized by reacting η7-C7H7Mo(CO)2Br with the corresponding sodium amides. The amido compound with R=H can also be obtained from η7-C7H7MO(CO)2CH3 in liquid ammonia. Reaction of the products with CH3OH yields the known complex η3)-C7H7(CO)2Mo(μ-OCH3)3Mo-η3-C7H7.
N-Methylsubstituierte Hydrazinderivate der Phosphorsäure aus Phenoxy-phosphoryl-dichlorid und aus Phenoxy-thiophosphoryl-dichlorid / N-Methyl Substituted Hydrazine Derivatives of Phosphoric Acid from Phenoxy-phosphoryl-dichloride and from Phenoxy-thiophosphoryl-dichloride
Authors: Bünger Thomas , Engelhardt Udo 
Published: February 2015

Abstract
C6H5OP(X)Cl2 (X=O, S) reacts with 1,2-dimethylhydrazine, 1,1-dimethylhydrazine or methylhydrazine, resp., to give the new dihydrazido derivatives la, 2a, 2b, or 3a and 3a-1, resp. Their 1H NMR and 31P NMR data are given.
An Investigation of AlCl3 Solutions in Ethers by 27Al NMR Spectroscopy
Authors: Nöth Heinrich , Rurländer Robert , Wolfgardt Peter 
Published: February 2015

Abstract

27Al NMR studies of AlCl3 solutions in diethyl ether reveal the presence of AlCl4 at high concentrations. This ion can also be recognized besides AlCl3·OR2 at low temperature in dilute solutions, while at 25 °C a single signal is observed, which represents the average of all species in solution. More extensive dissociation of AlCl3 results in tetrahydrofuran. The main species in equilibrium with one another are AlCl3·2THF, AlCl-
4 and AlCl2(THF)+
2.
Nearly quantitative dissociation to yield AlCl-
4 and [AlClL5]2+ occurs in dilute solutions of AlCl3 in monoglyme (L reprents one oxygen donor atom); at higher concentration an adduct AlCl3·L with Al in a tetrahedral environment is also present. This trend towards extensive dissociation is also observed in the solutions of AlCl3 in diglyme and triglyme. Relative peak areas are in agreement with the formation of a 1:1 electrolyte [AlCl2L4]+AlCl-
4 in diglyme, whereas additional dissociation into [AlClL5]2+ and AlCl-
4 occurs in triglyme.
Die Kristall- und magnetische Struktur von BaCrF5 / Crystal and Magnetic Structure of BaCrF5
Authors: Holler H. , Kurtz W. , Babel D. , Knop W. 
Published: February 2015

Abstract
A single crystal X-ray structure analysis of orthorhombic BaCrF5 (a = 1393.8(1), b = 571,1(1), c = 494,7(1) pm), which crystallizes in the structure type of BaGaF5, space group P212121, yielded Cr-F distances in the range of 187.3 to 194.9 pm, average 190.2 pm. Using powder neutron diffraction data taken at 2.2 K a G-type antiferromagnetic structure with spin alignment along the c direction of the lattice was worked out. Single crystal susceptibility data were consistent with this model and in addition showed a small net moment, probably due to spin canting, to be present below the Neel temperature of TN = 3.4 K. The orientation of this moment along the b axis is in accordance with the space group symmetry as well, chemical and magnetic cell being the same. From powder susceptibility data an exchange energy of -3.74 K (g = 2.02) was obtained by fitting Fisher's model. The low bridging angle of Cr-F-Cr = 137.4° within the cis corner-sharing chain of octahedra is made responsible for the weak antiferromagnetism in BaCrF5, which is compared to that of other chromium(III) fluorides.
Di- und trimeres Dimethylaminoisocyanat. Strukturen und Spektren / Di- and Trimeric Dimethylaminoisocyanate. Structures and Spectra
Authors: Zürn V. , Schwarz W. , Rozdzinski W. , Schmidt A. 
Published: February 2015

Abstract
N-Heterocyclic Compounds N,N-Dimethyl-N′,N′-bis(trimethylsilyl)hydrazine reacts with fluorophosgene to yield 5,5-dimethyl-3-dimethylamino-2,4-dioxo-5-azonia-imidazolidide (1). With phosgene, 1-methyl-2-chloroformyl-4-dimethylamino-1,2,4-triazolidine-3,5-dione (5) can be prepared. The thermal decomposition of N,N-dimethyl-N'-carbomethoxi-N′-trimethylsüyl-hydra-zine gives 1,3,5-tris(dimethylamino)-1,3,5-hexahydrotriazine-2,4,6-trione (2) and 1,2-dimethyl-4-dimethylamino-1,2,4-triazolidine-3,5-dione (3). 2 can also be prepared by thermal decomposition of N.N-dimethyl-N′-carbomethoxi-N′-fluoroformylhydrazine (4). The crystal and molecular structures of 1 and 2 were determined by X-ray analysis. The 1H NMR and vibrational data of 1-5 were communicated. The mass spectra of 1-3 were measured and discussed.
Einfluß der Adsorption auf die elektrochemische Reduktion von 1-Nitro-2-naphthol an Kohlenstoff-Faser-Elektroden / Influence of the Adsorption on the Electrochemical Reduction of 1-Nitro-2-naphthol at Carbon Fibre Electrodes
Authors: Theodoridou Elli , Karabinas Pantelis , Jannakoudakis Dimitrios 
Published: February 2015

Abstract
In the electrochemical reduction of 1-nitro-2-naphthol at carbon fibre electrodes an adsorption peak cathodic of the diffusion-controlled peak is obtained, as it happens in processes involving a strong adsorption of the reactant. This adsorption peak appears when the electrodes remain at positive potentials (+1V) in acidic solutions of the nitronaphthol and its interpretation is corroborated by its scan rate and concentration dependence.
Die Struktur des Na7Ga13-I und ein Konzept zur bindungsmäßigen Deutung / The Structure of Na7Ga13-I and its Characterization by a Bonding Scheme
Authors: Frank-Cordier Ursula , Cordier Gerhard , Schäfer Herbert 
Published: February 2015

Abstract
The new compound Na7Ga13-I crystallizes in the trigonal-rhombohedral system, space group R3m, with the constants a = 1496.5(3) pm, c = 3893(1) pm, c/o = 2.60.
The Ga atoms form Ga12 icosahedra and Ga15 clusters, connected to a threedimensional net. The arrangement of these clusters is related to the MgCu2 structure. The Na content of this compound correlates with the number of electrons necessary for a stable electron configuration in the Ga partial structure.
The BaAl4 type structure of NaGa4 has been confirmed by single crystal data
Darstellung und Kristallstruktur von Arsen(III)phosplior(V)oxid, AsPO4 / Preparation and Crystal Structure of Arsenic(III) Phosphorus(V) Oxide, AsPO4
Authors: Bodenstein Doris , Brehm Axel , Jones Peter G. , Schwarzmann Einhard , Sheldrick George M. 
Published: February 2015

Abstract
The compound ASPO4 was prepared from AS2O3 and P2O5 in a sealed tube at 673 K. The crystal structure, isostructural with AsO2, was refined to R = 0.021 [Pnma, a - 843.15(10), b = 502.29(10), c = 720.39(12) pm, Z = 4]. The structure consists of infinite layers. The arsenic(III) atoms are coordinated by three oxygen atoms at right angles; phosphorus(V) by four oxygens in the form of a distorted tetrahedron
Phasenbeziehungen im System As2Te3—AsI3 und die Kristallstruktur von As5Te7I / Phase Relations in the System As2Te3-AsI3 and the Crystal Structure of As5Te7I
Authors: Kniep Rüdiger 
Published: February 2015

Abstract
The system As2Te3-AsI3 is quasibinary and includes the intermediate phases As5Te7I and α-AsTeI with incongruent melting behaviour. The crystal structure of AssTe7I contains ribbons of condensed octahedral chains sharing common edges. Arsenic atoms are situated in the centres of the octahedra and - in a trigonal-pyramidal arrangement - at the borders of the ribbons. There are close relationships between the crystal structures of As2Te3 and AssTe7I as well as As5Te7I and α-AsTeI. The particular expansion of the As5Te7I one-phase region within the quasibinary system is discussed with respect to these structural relations
Metallorganische Verbindungen der Lanthanoiden, XTTT [1] Tris(di-f-butylarsin)-Derivate von Yttrium, Lanthan, Praseodym, Holmium, Erbium, Thulium und Lutetium / Organometallic Compounds of the Lanthanides, XIII [1] Tris(di-t-butylarsine) Derivatives of Yttrium, Lanthanum, Praseodymium, Holmium, Erbium, Thuhum, and Lutetium
Authors: Schumann Herbert , Frisch Georg-Michael 
Published: February 2015

Abstract
Lithium (di-t-butyl) arsenide reacts with the trichlorides of yttrium, lanthanum, praseodymium, holmium, erbium, thulium, and lutetium under elimination of lithium chloride and formation of the corresponding tris(di-t-butylarsine) derivatives
Trichonnethylphosphonsäuredihydrazid und 3.6-Bi8(trichlormethyl)-3.6-dioxo-1.2.4.5-tetraaza-3.6-diphosphacyclohexan / Trichloromethylphosphonic Acid Dihydrazide and 3,6-Bis(trichloromethyl)-3,6-dioxo-1,2,4,5-tetraaza-3,6-diphosphacyclohexane
Authors: Engelhardt Udo , Kirner Ingeborg 
Published: February 2015

Abstract
The title compounds are prepared from trichloromethylphosphonic acid dichloride and excess hydrazine hydrate, and from the dihydrazide and the dichloride in the presence of triethylamine, resp. They are characterized by elemental analysis, mass spectra, 1H and 31P NMR spectra, IR and Raman data. Thin layer chromatographic experiments show that in the raw material of the ring compound two isomers (probably cis- and trans-) are present, whereas in the recrystallized product only one isomer can be detected. Attempts of a preparative separation of isomers were unsuccessfull so far due to very low concentrations of the product with the slightly higher Rf. Single crystals of the isolated ring compound decompose on irradiation with X-rays
Strukturchemie von Verbindungen des pentakoordinierten Siliciums. Das Bis(ethylendioxy)methylsilan-Anion / Structural Studies of Pentacoordinate Silicon. The Bis(ethylenedioxy)methylsilane Anion
Authors: Schomburg Dietmar 
Published: February 2015

Abstract
Hexamethylendiammonium-bis(ethylenedioxy)methylsilane crystallizes in the hexagonal space group P6122, Z = 6 with a= 11.902(1), c = 30.148(4) A. The structure was refined to R - 0.041 using 2281 independent reflections. The geometry around the pentacoordinate silicon atom is between a trigonal bipyramid and a square pyramid. Oeq-Si-Oeq 136.0(1)°, Oax-Si-Oax 161.7(1)°. The Si-Oax bond lengths are 1.749(2) and 1.769(2) A, the Si-Oeq 1.711(2) and 1.735(2) A, Si-Ceq 1.876(3) A. The compound forms strong N-H ··· O hydrogen bonds between cation and anion. The cation lies on a crystallographic twofold axis
On the Extraction of Uranium from Sea Water by a Complexing Resin
Authors: Schwochau K. , Astheimer L. , Schenk H.-J. , Witte E. G. 
Published: February 2015

Abstract
A cross-linked polyacryl resin containing amidoxime or related functional groups is capable of concentrating uranium from natural sea water. The resin presents a uranium loading of more than 3000 ppm; moreover it has a higher selectivity, uptake rate, and attrition stability than hydrous titanium oxide
Reactions of n-C5H5Co(CO)2 and n-Me3SiC5H4Co(CO)2 with (XCN)2 and X(CN)2 (X = S or Se)
Authors: Morán Moisés , Ibáñez Augusto 
Published: February 2015

Abstract
The pseudohalogens (XCN)2 (X = S or Se) react with n-C5H5Co(CO)2 and n-Me3SiC5H4Co(CO)2 with formation of the 18 electron complexes, RCo(CO)(XCN)2 (R = n-C5H5 or n-Me3SiC5H4). By reactions with X(CN)2 (X = S or Se), the cyclopentadienyl cobalt dicarbonyls are transformed into the mixed complexes, RCo(CO)(CN)(XVN) (R = n-C5H5 or n-Me3SiC5H4. All the compounds are characterized by elemental analysis, IR, electronic and 1H NMR spectra. The thiocyanogen derivatives undergo linkage isomerism (N→S) in polar solvents.
Beiträge zur Chemie des Phosphors, 109 [1] t-Bu6lAs2P6 - der erste Phosphor-Arsen-Polycyclus / Contributions to the Chemistry of Phosphorus, 109 [1] t-Bu6As2P6 - the First Phosphorus Arsenic Polycycle
Authors: Baudler Marianne , Aktalay Yusuf , Heinlein Thomas , Tebbe Karl-Friedrich 
Published: February 2015

The first phosphorus arsenic polycycle t-Bu6As2P6 (1) was synthesized by dehalogenation of a 3:1 mixture of tert-butyldichlorophosphane and phosphorus trichloride using magnesium. 1 has been characterized by spectroscopic methods and by a crystal structure analysis having the t-Bu6Ps-analogous 2,2′,3,3′,4,4′-hexa-tert-butyl-l′-diarsa-2,2′,3,3′,4,4′-hexaphospha- bicyclobutane structure. In solution, the rotation around the exocyclic As-As bond is restricted already at room temperature.
1 crystallizes triclinically in the space group PT (No. 2) with a = 919.4 pm, b = 924.3 pm, c = 1171.7 pm, a = 97.21°, β = 102.98°, γ = 112.75°, and Z = 1 formula unit (V = 0.8694 nm3, Dx = 1.295 Mg · m-3). The crystal structure has been solved by 'direct methods' and refined to R = 0.048 with 2131 observed reflections. The molecule with symmetry C1 consists of two trans oriented and slightly folded four-membered P3As rings. The exocyclic bond length (d(As-As) = 244.1 pm) as well as the average endocyclic bond lengths d̅(As-P) = 235.6 pm; 3d̅(P-P) = 222.6 pm) are normal. The arrangement of the tert-butyl substituents with average bond lengths d̅(P-C) = 189.9 pm and d̅(C-C) = 1 5 2 . 5 p m is all-trans.
Zur Elektrochemie von Metall(O)-Verbindungen, V [1] Reaktionen von Diazadien-Metall(VIb)-carbonylkationen und -anionen / Electrochemistry of Metal(O) Compounds, V [1] Reactions of Diazadiene Metal(VIb) Carbonyl Cations and Anions
Authors: Dieck Heindirk torn , Kühl Ewald 
Published: February 2015

Abstract
Carbonyl complexes of chromium, molybdenum and tungsten of the type DAD M(CO)4 with DAD - diazadiene (R-N=CR′-CR′=NR) are shown by cyclic voltammetry to undergo electron transfer reactions to [DAD M(CO)4]+ and [DAD M(CO)4]-. The rate of subsequent chemical reactions with nucleophiles or by loss of ligands depend on the sol-vent, the metal and the ligands' electronic and steric properties. Chromium(+I) is more readily stabilized than Mo(+I) or W(-I) while the opposite is true for the stability of the anions formed. The dimerisation of a low-coordinate species DAD Mo(CO)3 from the reduction of DAD Mo(CO)3(CH3CN) is detected electrochemically. The stabilization of oxidation states +1 and -I is briefly discussed in view of the DAD ligand properties.
Acyclische Liganden mit fixierter Koordinationsgeometrie, 1:2-Komplexe von Cobalt(II) mit den Anionen von 2.2′-Dihydroxydiphenyloxid und -sulfid -Kristall-und Molekülstruktur von Natrium-bis[diphenylsulfid-2.2′ -diolato(2-)]cobaltat(II>- Aceton-Wasser (1/2/1) / Acyclic Ligands with Fixed Coordination Geometry, I 1:2 Complexes of Cobalt(II) with the Anions of 2,2′-Dihyydroxydiphenyloxide and -sulfide - Crystal and Molecular Structure of Sodium bis[diphenylsulfide-2,2′-diolato(2-)]cobaltate(II)- Acetone-Water (1/2/1)
Authors: Müller Hartmut , Holzmann Arno , Hinrichs Winfried , Klar Günter 
Published: February 2015

The synthesis of bis[diphenylchalcogenide-2,2′-diolate(2-)]-cobaltate(II) compounds is described. In these complexes diphenyloxide-2,2′-diolate acts as a bidentate, diphenylsulfide- 2,2′-diolate as a tridentate chelating ligand leading to tetrahedral or octahedral coordinated cobalt(II), resp.
An X-ray analysis of sodium bis[diphenylsulfide-2,2′-diolate(2-)]cobaltate(II)-acetonewater (1/2/1) shows the ligands to occupy fac-, their sulfur atoms cis-positions. The Co-0 distances (average 204.5 pm) are in the normal range while the C-S distances (average 248.5 pm) are longer than usually found indicating weaker bonds to sulfur than to oxygen.
Reactions of OH Radicals with Acetylacetone in Aqueous Solution. A Pulse Radiolysis and Electron Spin Resonance Study
Authors: Broszkiewicz R. K. , Söylemez T. , Schulte-Frohlinde D. 
Published: February 2015

Abstract
Pulse radiolysis experiments monitoring optical absorbance as well as conductivity and in-situ ESR radiolysis studies show that the OH radical reacts with the enol (k=8.6 x 109 M-1 s-1) and the enolate (k = 7.4 X 109 M-1 s-1) forms of acetylacetone by addition to the C = C double bond in aqueous N2O saturated solution. The OH reaction with enol leads to equal amounts of two radicals, CH3COCHOHCOHCH3 (2) and CH3COCHC(OH)2CH3 (4), as determined by scavenger reactions. At pH less than 1 the radical CH3COCHCOCH3 (1) is observed by ESR spectroscopy showing that radical 2 and/or 4 eliminate water by proton catalyzed reactions. Under alkaline condition the OH adducts to the enolate eliminate OH -with rate constants larger than 105 s-1 leading to radical 1. G(OH-) is determined to be 5.6 showing that addition is the main reaction of OH with enolate. To a much smaller degree the OH radical is proposed to abstract an H atom from that CH3 group which is attached to the C -C double bond in enol and enolate, producing substituted allyl radicals which absorb in the visible region. The reaction of OH with the keto form has not been observed indicating that the rate constant of this reaction is significantly smaller than those with enol and enolate.