bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stress Relaxation of Alginate Gels Crosslinked by Various Divalent Metal Ions
Authors: Yonese Masakatsu , Baba Kazuhiko , Kishimoto Hiroshi 
Published: July 2006

Abstract
Rheological properties of Alginate (Alg) gels were studied by measuring tensile stresses under small strains. The Alg gel rods were prepared in CaCl2, SrCl2, BaCl2, and Pb(NO3)2 solutions in the range of 0.03–1.0 mol dm−3. Their stresses showed long relaxation processes. By curve fitting method, equilibrium elastic moduli Ge, spontaneous elastic moduli Ge+Gr and relaxation times τ were obtained. The results Ge were independent of strains γ, and Gr and τ increased as increasing γ. The effects of Ca ion concentrations CCa on the elasticities were discussed by taking account of the ratio of Ca ion bindings obtained by dialysis equilibrium and that of junction formation obtained by circular dichroism. The values of Ge were analyzed by the theory of swollen gels. The number of the junctions was found to be constant in the region of CCa&gt;0.03 mol dm−3, and slight increases of Ge to be due to changes of the water content and the density of the Alg gels. The magnitudes of Ge and Gr depended on the kind of counterions, and decreased in the order, Ba-&gt;&gt;Ca-&gt;Sr-&gt; PbAlg; this was almost the same as that of the ion selectivities.
Magnetic Behavior of Spin-Crossover Iron(III) Complexes Adsorbed on the Surface of Silicon Dioxide and Metal Dilution Effects on Magnetism
Authors: Maeda Yonezo , Tomokiyo Masahiro , Kitazaki Kenji , Takashima Yoshimasa 
Published: July 2006

Abstract
The effects of metal dilution and adsorption on the surface of silicon dioxide on the spin-crossover behavior of [Fe(acpa)2]PF6, [Fe(acpa)2]BPh4, and [Fe(bzpa)2]PF6, which undergo fast spin-state interexchange on the 57Fe Mössbauer timescale have been studied by using 57Fe Mössbauer and EPR spectroscopies, powder X-ray diffraction and magnetic susceptibility, where Hacpa is N-(1-acetyl-2-propylidene)-2-pyridylmethylamine and Hbzpa N-(1-benzoyl-2-propylidene)-2-pyridylmethylamine. Solid solution compounds, [FexCo1−x(acpa)2]BPh4(x=0.035 and 0.074) and [Fe0.05Co0.95(bzpa)2]PF6 exhibit spin-crossover phenomena. No difference in the spin-state interexchange rate is observed between the diluted compound and the corresponding undiluted one as far as the rates are evaluated by Mössbauer spectroscopy. Mössbauer spectra for [Fe0.074Co0.926(acpa)2]PF6 exhibit only a pair of quadrupole doublets assigned to the low-spin state in the temperature range from 78 to 298 K. The spin-state interexchange rates for [Fe(acpa)2]BPh4 and [Fe(bzpa)2]PF6 adsorbed on the surface of silicon dioxide become slow compared to those for the corresponding pure complexes and the narrowing of the spin-state transition temperature range is observed. On the contrary no detectable differences in the spin-state interexchange rates are observed between the Mössbauer spectra for [Fe(acpa)2]PF6 adsorbed on the surface of silicon dioxide and that for the pure complexes. These observations are interpreted in terms of a spin-state transition behavior in these complexes which is affected by the packing state in the solid state, which is dependent on the characteristic structure of the respective complex.
NMR Spectroscopic Study of the Conformational Preference of Methoxycarbonyl and Methyl Substituted Thiophenecarbaldehydes. Possibility of a Hydrogen-Bond-Like Interaction between Formyl C–H and the Ester Carbonyl Group
Authors: Satonaka Hajime , Abe Kazuhisa , Hirota Minoru 
Published: July 2006

Abstract
The predominance of planar C–H/O=C approached conformations in methyl 3-formyl-2-, 2-formyl-3-, and 4-formyl-3-thiophenecarboxylates was shown experimentally by the chemical shifts of the formyl protons, the unusually large 1JCH values of the formyl groups, and their infrared C–H and C=O absorptions. The stability of the C–H/O=C approached conformation was attributed to the hydrogen-bond-like interaction between the two groups. The considerably large positive bond population between non-bonded H/O and the additional charge separation indicated by the MNDO calculations supported the presence of the intramolecular hydrogen bond.
Enantioselective Reduction of 2-Methyl-3-oxopropionate by Bakers’ Yeast
Authors: Nakamura Kaoru , Miyai Takehiko , Ushio Kazutoshi , Oka Shinzaburo , Ohno Atsuyoshi 
Published: July 2006

Abstract
Various esters of 2-methyl-3-oxopropionic acid were subjected to the reduction with bakers’ yeast. Effects of size and bulkiness as well as hydrophobicity of alcohol moieties of the substrates on the enantioselectivity of the reduction were investigated. The substrates having bulky ester groups gave the (R)-hydroxy esters with high enantioselectivities. A mechanism to alter the stereoselectivity of the reduction is proposed.
Clay Montmorillonite: An Efficient, Heterogeneous Catalyst for Michael Reactions of Silyl Ketene Acetals and Silyl Enol Ethers with α,β-Unsaturated Carbonyl Compounds
Authors: Kawai Motomitsu , Onaka Makoto , Izumi Yusuke 
Published: July 2006

Abstract
The Michael addition of silyl ketene acetals to α,β-unsaturated esters (enoates) is investigated. The reaction is catalyzed by clay montmorillonite (solid acid) most effectively among various, homogeneous and heterogeneous acid promoters. The montmorillonite-catalyzed reaction has several prominent features: (1) Not only α- or β-monosubstituted acrylates but also α,β- or β,β-disubstituted acrylates are applicable. (2) The highly regioselective 1,4-addition to a polyenoate is achievable. (3) The Michael adduct can be obtained in the form of a labile silyl ketene acetal owing to a simple work-up procedure. The Michael reaction of a silyl enol ether and silyl ketene acetals with α,β-unsaturated ketones (enones) is also described.
A Green Complex from the Reaction of a Binuclear Copper(II) Complex of 2-Hydroxy-1,4-butanediamine-N,N,N′,N′-tetraacetic Acid and H2O2
Authors: Kawata Satoshi , Iwaizumi Masamoto , Kosugi Hiroshi , Yokoi Hiroshi 
Published: July 2006

Abstract
Spectrophotometric studies have revealed that a green complex is formed by the reaction of a blue binuclear copper(II) complex of 2-hydroxy-1,4-butanediamine-N,N,N′,N′-tetraacetic acid and H2O2, although analogous binuclear complexes of 2-hydroxy-1,3-propanediamine- and 3-hydroxy-1,5-pentanediamine-N,N,N′,N′-tetraacetic acids are unreactive to H2O2.
Prebiotic Synthesis Obeys the Rule of Topological Charge Stabilization
Authors: Aihara Jun-ichi 
Published: July 2006

Abstract
Most organic molecules synthesized in primitive-Earth-simulation experiments conform to the rule of topological charge stabilization. Heteroatoms in these molecules are all located at the best sites to stabilize the conjugated systems. The situation must be the same for organic molecules formed under prebiotic conditions on primitive Earth.
Structural Study of Potassium Gallate Glasses by Mössbauer Spectroscopy and Differential Thermal Analysis
Authors: Nishida Tetsuaki , Saruwatari Setsuko , Takashima Yoshimasa 
Published: July 2006

Abstract
Mössbauer spectra of a series of potassium gallate (Ga2O3-based) glasses, containing 10 mol% Fe2O3 as a Mössbauer probe, consist of two types of quadrupole doublet peaks due to tetrahedral Fe3+ ions bonded with nonbridging and bridging oxygen atoms and those bonded only with bridging oxygen atoms. This indicates that all the Fe3+ ions are present at the substitutional sites of the tetrahedral Ga3+ ions constituting the skeleton of network structure. An increase in the K2O content results in an increased fraction of the FeO4 (and GaO4) tetrahedra bonded with nonbridging oxygen atom(s). A Mössbauer spectrum of 70K2O·20Ga2O3·10Fe2O3 glass consists of only one quadrupole doublet peak due to the FeO4 tetrahedra having nonbridging oxygen atom(s). This suggests that each of the Fe3+ (and also Ga3+) ions is tetrahedrally bonded with at least one nonbridging oxygen atom. Structural information obtained from the Mössbauer measurements is confirmed by DTA measurements of the gallate glasses, Tg of which shows a drastic decrease from 647 to 555 °C when the K2O content is changed from 35 to 70 mol%.
Novel Preparation of 1- and 3-Substituted Bicyclo[3.2.2]nona-3,6,8-trien-2-ones from Tropones and 2,3-Bis(methoxycarbonyl)-7-oxabicyclo[2.2.1]heptadiene by High-Pressure Cydoaddition-Thermal Cycloreversion Procedure
Authors: Tian Guan Rong , Sugiyama Shigeru , Mori Akira , Takeshita Hitoshi 
Published: July 2006

Abstract
The Diels–Alder adduct of tropone with 2,3-bis(methoxycarbonyl)-7-oxabicyclo[2.2.1]hepta-2,5-diene formed homobarrelenone on heating at 130 °C. Similarly prepared were 1-hydroxy-, 3-methoxy-, 1-chloro-, and 3-chlorohomobarrelenones. High-pressure cycloaddition improved the yields of the Diels–Alder adducts. In reactions of 2-methoxy- and 2-chlorotropones with the 7-oxanorbornadiene derivative, the endo-isomers were predominantly produced together with the exo-isomers.
The Polymerization of Benzene Catalyzed by a Copper(I) Chloride–Aluminium Chloride–Oxygen System
Authors: Toshima Naoki , Kanaka Keiichi , Koshirai Atsunori , Hirai Hidefumi 
Published: July 2006

Abstract
The polymerization of benzene to poly(1,4-phenylene) (PPP) has been done successfully using copper(I) chloride and aluminium chloride as catalysts under oxygen. Since copper(I) chloride and aluminium chloride form a double salt (aluminium copper(I) chloride, AlCuCl4) and are soluble in benzene, a high homogeneity of the reaction system has been achieved and the polymerization reaction proceeds without any evolution of hydrogen chloride. The polymerization products contained an insoluble dark brown solid and a benzene-soluble tarry mass. The solid product has been determined to be PPP by comparison with an authentic sample. The product PPP was obtained in a yield of more than 100%, based on the molar quantity of copper(I) chloride, by controlling the quantity of aluminium chloride. For example, the treatment of benzene with aluminium chloride and copper(I) chloride (20:3:1 in molar ratio) under 1 atm of oxygen at 70 °C for 24 h gave PPP in a 187% yield, based on copper(I) chloride. This reaction could be carried out by the use of oxidants other than oxygen and by the use of low-valent metal salts other than copper(I) chloride, although a copper(I) chloride–aluminium chloride–oxygen system is most suitable for the polymerization of benzene in terms of the yield of PPP and the convenience of the reaction.
Kinetics of the Interaction between DNA and Acridine Orange
Authors: Kure Naohisa , Sano Takayuki , Harada Shoji , Yasunaga Tatsuya 
Published: July 2006

Abstract
Both static and kinetic investigations have been performed on the interaction of calf thymus DNA with Acridine Orange (AO). The binding isotherm obtained spectrophotometrically was analyzed by a site exclusion theory and revealed the presence of two binding modes of dye molecule corresponding to intercalation and dimerization on DNA. In the kinetic experiments focusing on the intercalation mode by the temperature-jump technique, three relaxations were observed. From the analyses of both the relaxation time and amplitude, the two fast relaxations were ascribed to parallel binding reactions including a bimolecular pathway for direct transfer of dye molecule on the polymer and the slow relaxation was attributable to a conformational change of DNA molecules. The binding parameters kinetically obtained suggest that 80% of bound AO is in intercalated form and the remainder is in partially intercalated one as an external bound form.
Solvation of Alkylbenzenes Studied by Photoelectron Emission Spectroscopy of Organic Solutions
Authors: Nakayama To-oru , Watanabe Iwao , Ikeda Shigero 
Published: July 2006

Abstract
The external ionization potentials for alkylbenzenes in acetonitrile and nitrobenzene have been measured by photoelectron emission spectroscopy to determine electronic polarization energies and reorganization energies. The polarization energy is used to discuss the solvation structure of alkylbenzene. The solvation behavior of alkylbenzene is found to be different from that of butylamine, previously reported. We have obtained the evidence of the approach of solvent molecules to the plane of benzene ring.
Incommensurate Phase Transitions and Anomalous Lattice Heat Capacities of Biphenyl
Authors: Saito Kazuya , Atake Tooru , Chihara Hideaki 
Published: July 2006

Abstract
Heat capacities of crystalline biphenyl were measured between 3 and 300 K by adiabatic calorimetry and some thermodynamic functions including the calorimetric standard entropy were tabulated. Thermodynamic properties of the successive phase transitions were determined; for the twist transition at (40.4±0.2) K, ΔtrsH=(5.02±0.08) J·mol−1 and ΔtrsS=(0.129±0.003) J·K−1·mol−1, and for the lock-in transition at (16.8±0.1) K, ΔtrsH=(0.15±0.02) J·mol−1 and ΔtrsS=(0.009±0.001) J·K−1·mol−1. Anomalously large heat capacities at low temperatures were analyzed based on lattice dynamics calculation, and the crossover of the low temperature heat capacities of biphenyl and p-terphenyl was attributed to the greater activity of the twisting mode in biphenyl. The relation of the bond flexibility to the incommensurability is discussed through the comparison of the low temperature heat capacities of biphenyl, p-terphenyl, and 4,4′-difluorobiphenyl.
Heats of Solution and Viscosity B Coefficients for Some Cyclic Mono- and Bis(quaternary ammonium) Salts
Authors: Tamaki Kunio , Kitazawa Takeshi , Asada Misako 
Published: July 2006

Abstract
Heats of solution and viscosity B coefficients, for cyclic mono(quaternary ammonium) salts, (CH3)2N(CH2)nBr (n=4–6) and cyclic bis(quaternary ammonium) salts, (Remark: Graphics omitted.) (n=1–3) in water were measured, and the effect of structural changes in the solvent water upon the dissolution of both series of electrolytes is discussed.
Natural-Abundance Oxygen-17 Magnetic Relaxation in Aqueous Solutions of Carbohydrates
Authors: Uedaira Hisashi , Ikura Mitsuhiko , Uedaira Hatsuho 
Published: July 2006

Abstract
The spin-lattice relaxation times, T1, of H217O have been measured for aqueous solutions of several pentoses, hexoses, di-, and trisaccharides as a function of the concentration at 25 °C. The coordination numbers, nh, and the rotational correlation times, τch, of water molecules around the sugars were estimated and compared with that of pure water, τc°. The value of τch⁄τc°=4.10 for glucose is largest, while that of τch⁄τc°=2.82 for ribose is the smallest, among these sugars. The value of nh (τch⁄τc°−1) was defined as the dynamic hydration number. The dynamic hydration numbers showed a good correlation with the mean number of the equatorial OH groups and the limiting diffusion coefficients.
A New Method for the Calculation of the Sextet Polynomial of Unbranched Catacondensed Benzenoid Hydrocarbons
Authors: Gutman Ivan , Cyvin Sven J 
Published: July 2006

Abstract
A method for the calculation of the sextet polynomial of unbranched catacondensed benzenoid molecules is proposed. It requires the multiplication of a small number of 2×2 matrices and is therefore very simple.
The Ei Reaction of Substituted threo- and erythro-1-Phenylethyl Phenyl Sulfoxides
Authors: Yoshimura Toshiaki , Tsukurimichi Eiichi , Iizuka Yukihiko , Mizuno Hironobu , Isaji Hiroshi , Shimasaki Choichiro 
Published: July 2006

Abstract
Substituted (RS,SR)-1-phenylethyl phenyl sulfoxides (threo) (XC6H4S(O)CH(CH3)C6H4Y) and some substituted (RR,SS)-sulfoxides (erythro) were prepared and kinetic investigation for the thermal decomposition was carried out at 80.0, 90.0, and 100.0 °C in dioxane. Hammett plots for threo-XC6H4S(O)CH(CH3)C6H5 gave positive ρ-values (ρX=0.60–0.64 at three temperatures), while those for threo- and erythro-C6H5S(O)CH(CH3)C6H4Y snowed V-shape lines with bottoms at the m-OCH3 substituent though the effects of the substituents are small. Meanwhile, large kinetic isotope effects for threo- and erythro-C6H5S(O)CH(CD3)C6H4Y (Y=H, p-OMe, m-Cl) (kH⁄kD=4–6) were observed at all temperatures. The activation energies were in the range of 104–121 kJ mol−1 for all sulfoxides, while the activation entropies were relatively large (7–37 J K−1 mol−1) and were correlated with Hammett σ-values to give small negative trend. Reactions of all erythro-isomers examined were 2–3 times faster than those of the corresponding threo-isomers. From these results, it is suggested that the pyrolysis of 1-arylethyl aryl sulfoxides proceeds via a concerted mechanism in which the transition state is variable from an El-like to a conjugated one. In the latter transition state, conjugation of the phenyl group bearing the electron-withdrawing substituent with the developing π-bond electron acidifies the β-proton.
The Synthesis and Chemical Reaction of Magnesium and Calcium Bis(phosphorodiamidates) with Acids
Authors: Sato Shoji , Takayanagi Takao , Watanabe Makoto 
Published: July 2006

Abstract
Magnesium bis(phosphorodiamidate) hexahydrate and calcium bis(phosphorodiamidate) dihydrate were made by adding an aqueous solution of magnesium chloride or calcium chloride to a sodium phosphorodiamidate solution. These phosphorodiamidates reacted with the water of crystallization and/or adsorbed water to produce phosphoramidate and orthophosphate. They also reacted with HCl gas, acetic acid, and oxalic acid to make polyphosphates and phosphates with amino and/or imino groups. Several typical reactions are as follows:
(Remark: Graphics omitted.)
where M and HA stand for alkaline earth metal and acid respectively.
The Phase Transition of Quaternary Fluoroalkyl Halide Salts of 1,4-Diazabicyclo[2.2.2]octane
Authors: Terada Tohru , Nogami Takashi , Shirota Yasuhiko 
Published: July 2006

Abstract
The solid–solid phase transition of quaternary halide salts of 1,4-diazabicyclo[2.2.2]octane (DABCO) was investigated by DSC, Raman spectroscopies, and the measurements of the ionic conductivity of the halide anions. The DABCO salts studied are classified into two; one is the salt possessing both fluoroalkyl and alkyl groups, and the other the ones possessing the same fluoroalkyl groups at both ends of the molecule. The former molecule exhibited a gradual increase of the ionic conductivity above the transition temperature. The ionic conductivity of the former molecule was higher than that of the latter molecules and the symmetric quaternary alkyl halide salts of DABCO. These facts were explained by a spacer effect of the fluoroalkyl group. The temperature dependence of the Raman spectra of the former salt established that the fluoroalkyl group was much more rigid than the alkyl group, and that the molecular movement took place mainly at the alkyl group and the DABCO portion in the high temperature phase. One of the latter type of molecules exhibited a conductivity jump around the transition temperature.
Hexacarbonylmolybdenum(0)-Induced Dechalcogenization of Allylic Sulfides, Sulfones, and Selenides: Nucleophilic Substitution and Reductive Dechalcogenization
Authors: Masuyama Yoshiro , Yamada Kohji , Shimizu Soh-hei , Kurusu Yasuhiko 
Published: July 2006

Abstract
Hexacarbonylmolybdenum(0)-induced dechalcogenization of allylic sulfides I, sulfones II, and selenides III in refluxing dioxane, which led to nucleophilic substitutions with carbon nucleophiles. Attack of the relatively bulky nucleophile, 2-ethoxycarbonyl-2-sodiocyclopentanone occurred regioselectively at the less substituted end of the allyl unit after the dechalcogenization to give only one isomer. Attack of diethyl sodiomalonate to I and III occurred preferentially at γ-position, and that to II occurred preferentially at the more substituted end of the allyl unit after the desulfonylation. In the absence of the carbon nucleophiles, treatment of I, II, and III with Mo(CO)6 in refluxing dioxane caused reductive dechalcogenization. Addition of H2O accelerated the reductive dechalcogenization.
Synthetic Photochemistry. LII. Substituent Effects of a Bromine Atom on the High-Pressure Cycloaddition between 1-Acetyl-7-bromocyclohepta[b]pyrrol-2(1H)-one and 2,3-Bis(methoxycarbonyl)-7-oxanorbornadiene and the Photorearrangement of 2-Acetyl-9-bromo-2-azatricyclo[6.2.2.01,5]dodeca-4,6,9,11-tetraen-3-one
Authors: Tian Guan Rong , Mori Akira , Takeshita Hitoshi 
Published: July 2006

Abstract
A high-pressure cycloaddition reaction of 1-acetyl-7-bromocyclohepta[b]pyrrol-2(1H)-one and 2,3-bis(methoxycarbonyl)-7-oxanorbornadiene and a further thermolysis of [4+2] cycloadducts gave 2-acetyl-9-bromo-2-azatricyclo[6.2.2.01,5]dodeca-4,6,9,11-tetraen-3-one, which was photorearranged to 9-methylenebarbaralane and 5-methylenetricyclo[4.3.0.02,9]nonadiene derivatives. The product distribution of the photolysis was altered by a bromine atom.
Photochromism of 4-Oxazolyl Fulgides
Authors: Suzuki Hisao , Tomoda Akihiko , Ishizuka Mitsuo , Kaneko Akira , Furui Masami , Matsushima Ryoka 
Published: July 2006

Abstract
The thermal and photochemical stabilities of 2-[1-(2-phenyl-5-methyl-4-oxazolyl)]alkylidenesuccinic anhydrides (1) and (2) were studied. These compounds showed good thermal stabilities in PMMA film and low photochemical fatigue (PF≤0.03% /cycle) in a dilute toluene solution in the presence of air, compared with 3-furyl fulgide (3). Although in PMMA film the photochemical fatigue resistance property of the fulgides was poor, in comparison with that in solution, the addition of an organo-nickel stabilizer improved the property.
Aryliminodimagnesium Reagents. XV. Condensation with Nitrobenzene. Formation of Unsymmetrical Azobenzenes Favored by Long-Chain p-Alkoxy-Substituted Reagents
Authors: Okubo Masao , Matsuo Koji , Yamauchi Akira 
Published: July 2006

Abstract
In the reaction of p-MeC6H4N(MgBr)2 with p-alkoxynitrobenzene, no effect of alkoxyl chain length on the relative yields of azoxy and azo products was observed. In contrast, in the reaction of p-alkoxy-C6H4N(MgBr)2 with p-nitrotoluene, C12- and C18-alkoxyl chains led to the corresponding unsymmetrical azobenzenes in unexpectedly high yields. This result, arising from efficient condensation and deoxygenation processes, was explained in terms of cooperation of reagent molecules through their aggregation assisted by a novel tying effect of their long chains.
A NEW ROUTE FOR THE SYNTHESIS OF TETRAALKYLUREAS. THE REACTION OF CARBON MONOXIDE WITH SELENIUM AND DIALKYLAMINES
Authors: Kondo Kiyoshi , Sonoda Noboru , Yoshida Kokichi , Koishi Masafumi , Tsutsumi Shigeru 
Published: July 2006

Abstract
The reaction of carbon monoxide with selenium and dialkylamines followed by oxidation with molecular oxygen at 0°C gave bis(N,N-dialkylcarbamoyl) diselenide, pyrolysis of which yielded bis(N,N-dialkylcarbamoyl) selenide and tetraalkylurea.
THE COEXTRACTION OF WATER WITH ALKALI AND ALKALINE EARTH METALS HEXANITRODIPKENYLAMINATES AND ANALOGOUS AMINATES
Authors: Kawasaki Mikio , Tôei Kyoji , Iwachido Tadashi 
Published: July 2006

Abstract
Alkali and alkaline earth metal salts of hexyl (2,4,6,- 2′,4′,6′-Hexanitrodiphenylamine), α-hexyl (N-(2,4,6-trinitrobenzo)-2,4-dinitro-1-naphthylamine), and thiohexyl (1,3,7,9-Tetranitrophenothiazine-5-oxide) were extracted into nitrobenzene. The water in the nitrobenzene solution was determined by means of the Karl–Fischer method. It was found that the water content in the extract was greater than that in nitrobenzene which did not contain these salts. The behavior of water in nitrobenzene phase was discussed on the basis of absorption spectra in near infrared region and of proton magnetic resonance spectra.
TRANSFERENCE OF WATER TO THE NITROBENZENE PHASE FOR THE EXTRACTION OF TRIS(1,10-PHENANTHROLINE)IRON(II) CHELATE SALTS
Authors: Yamamoto Yuroku , Tarumoto Tsunehiko , Tarui Takao 
Published: July 2006

Abstract
The amount of water transferred to the nitrobenzene phase was determined for the extraction of ion pairs of tris(1,10-phenanthroline)iron(II) with halide and pseudohalide anions. The results were consistent with the number of water of crystallization of these salts.