bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aluminum Chloride–Tetraalkylammonium Halide Complex as a Novel Catalyst in Friedel–Crafts Alkylation. Direct Construction of the Chroman Structure from 1,3-Diene
Authors: Matsui Makoto , Yamamoto Hisashi 
Published: July 2006

Abstract
Tetrabutylammonium halides were found to accelerate Lewis acid-catalyzed Friedel–Crafts alkylation when trimethylhydroquinone and myrcene were used, followed by cyclization to give the chroman compound predominantly. For tetraalkylammonium salts which have long-chain alkyls and/or bromide, iodide counter anions promote the reaction in less-polar solvents. Phosphonium halides and sulfonium halide were also effective. The tetraoctylammonium bromide–aluminum chloride complex was an effective catalyst for the initial regioselective protonation of 7,11,15-trimethyl-3-methylene-1,6-hexadecadiene to give α-tocopherol in high yield.
High-Pressure Diels–Alder Reaction of Cyclooctatetraene with Dimethyl 1,4-Dimethyl-7-oxabicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylate. Single Crystalline State Valence Isomerization of a syn-Tricyclo[4.2.0.02,5]octane Derivative
Authors: Takeshita Hitoshi , Mori Akira , Kato Nobuo , Kurahashi Yoichi , Ito Masahito 
Published: July 2006

Abstract
High-pressure Diels–Alder reaction of cyclooctatetraene with dimethyl 1,4-dimethyl-7-oxabicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylate afforded six products, one of which was shown to be a 2 : 2-adduct having a syn-tricyclo[4.2.0.02,5]octane framework. Upon radiation with X-rays, the tricyclooctane derivative isomerized to a cyclooctadiene derivative.
Synthetic Modification of Cotylenol. Synthesis of 3α-Cotylenyl Methyl Dithiocarbonates with Four Diastereomeric Glycol Moieties and Their Plant Growth Regulating Activity
Authors: Kato Nobuo , Okamoto Hiroaki , Takeshita Hitoshi 
Published: July 2006

Abstract
To confirm the role of an electronegative substituent on the C-3 position of the cotylenol framework in exhibiting the biological activity, four diastereomers at the 8,9-glycol moieties of 3α-sulfur analogs, 3α-cotylenyl methyl dithiocarbonates, were synthesized. The 8β,9α-dihydroxy compound, which had the same stereochemistry regarding the glycol moiety with natural products, revealed similar biological activity in stimulating the germination of lettuce seeds.
Different Roles of Two Consecutive Leucine Residues in a Receptor-Tethered Ligand Peptide (SFLLRNP) in Thrombin Receptor Activation
Authors: Nose Takeru , Shimohigashi Yasuyuki , Okazaki Mika , Satoh Yusuke , Costa Tommaso , Shimizu Naokata , Ogino Yoshio , Ohno Motonori 
Published: July 2006

Abstract
A synthetic peptide, H–Ser–Phe–Leu–Leu–Arg–Asn–Pro–NH2, which corresponds to a ligand peptide tethered to a human thrombin receptor, was able to activate the thrombin receptor with no thrombin. In order to inspect the structural requisites of two consecutive leucines (Leu-3 and Leu-4) in receptor activation, two sets of analogs with substitutions at either position 3 or 4 were synthesized and evaluated for their ability to hydrolyze phosphoinositide in human neuroblastoma SH-EP cells. The replacement of Leu-4 by Ala drastically decreased the activity of the parent peptide (only about 4% activity), while that of Leu-3 retained about 50% activity. A similar result was obtained when replaced by Gly. Substitution by Phe for Leu-3 sustained full activity. Although the Leu-4/Phe substitution exhibited a slight reduction in activity, Leu-4/Ile substitution unexpectedly diminished the activity (20%). These results suggested that two consecutive leucines have different roles in receptor activation; i.e., Leu-3 behaves something like a connection of peptide units to construct a bioactive conformation and Leu-4 acts like a structural element essential for interactions with receptors.
Synthesis of Pyrrole Derivatives Using Thioimidates
Authors: Yokoyama Masataka , Menjo Yasuhiro , Wei He , Togo Hideo 
Published: July 2006

Abstract
Dimethyl acetylenedicarboxylate, ethyl propiolate, nitro olefins, or 2-nitroalkyl acetates react with thioimidate in the presence of organic bases to give the corresponding pyrroles in moderate-to-good yields.
A 1H and 13C NMR Study of the Structure of Sulfur-Stabilized Lithiated Allylic Carbanions
Authors: Glendenning Lionel , Field Leslie D , Haynes Richard K 
Published: July 2006

Abstract
NMR studies of the solution structures of lithiated (E)-1-(t-butylthio)but-2-ene (4) and lithiated (E)-1-(phenylthio)but-2-ene (6) are reported. The structure of lithiated (E)-1-(t-butylthio)but-2-ene (4) is best described as a transoid carbanion with the allylic carbons C1, C2, and C3 having intermediate sp2–sp3 hybridization. In (4) the heteroatom and non-allylic substituent do not play any significant role in carbanion stabilization. Lithiated (E)-1-(phenylthio)but-2-ene (6) differs from (4) in that it exhibits cis geometry about the C1–C2 bond and the phenylthio group participates in helping to stabilize allylic charge. There is a discrepancy between the geometry about the C1–C2 bond in the solution and solid structures of (4) in the presence of TMEDA.
Synthesis and Structure of a Novel Cyclic Polysulfide, 2,4,6-Tris[bis(trimethylsilyl)methyl]phenyloctathionane
Authors: Takeda Nobuhiro , Tokitoh Norihiro , Imakubo Tatsuro , Goto Midori , Okazaki Renji 
Published: July 2006

Abstract
A novel cyclic polysulfide, octathionane TbtCHS8 (7; Tbt = 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl) was synthesized by thermal reaction of the corresponding diazomethane TbtCHN2 with cyclooctasulfur (S8) in benzene in the dark. Molecular structure of 7 was determined by X-ray crystallographic analysis and the geometry of the CS8 ring was compared with that of theoretically optimized cyclononasulfur (S9). Desulfurization of 7 by triphenylphosphine afforded the corresponding pentathiane TbtCHS5.
Photoluminescence of 4,4′-Diaminobiphenyl
Authors: Rajendiran Narayanasamy , Swaminathan Meenakshisundaram 
Published: July 2006

Abstract
Fluorescence solvatochromic shifts of 4,4′-diaminobiphenyl (DABP) were found to be less than those of 4-aminobiphenyl and the difference mainly occured in hydrogen bonding solvents. This shows that the net effect of hydrogen bonding interactions of two amino groups is less than that of one amino group. The unusual fluorescence red-shift observed for the monocation of DABP relative to the neutral form is not because of the amino group becoming more basic, but because of a large solvent relaxation in aqueous media. As the entire molecule becomes planar upon excitation, its behavior is found to be similar to that of 2,7-diaminofluorene in the S1 state. pKa values for various prototropic reactions in the S0 and S1 states were determined and are discussed.
Photosubstitution Reactions of 4-Methyl-2-quinolinecarbonitrile with Arylalkanoic Acids. No Evidence for the External Magnetic Field Effects or Chiral Symmetry Breaking
Authors: Nakagaki Ryoichi , Takahira Osamu , Yamaoka Masaharu , Kashima Noriko 
Published: July 2006

Abstract
No appreciable magnetic field effects were observed on the relative quantum yield for photochemical reactions of 4-methyl-2-quinolinecarbonitrile with (R)-(−)-2-phenylpropionic, diphenylacetic, and 2,2-diphenylpropionic acids in benzene. Observed results were reasonably explained in terms of kinetic parameters which are dependent on and independent of an external magnetic field. (S)-(+)- and (R)-(−)-α-methoxyphenylacetic acids exhibit equivalent reactivity toward the excited state of 4-methyl-2-quinolinecarbonitrile in acetonitrile. No unusual phenomena were observed under well controlled conditions with sufficient repetitions.
Homogeneous Hydrogenation of Carbon Dioxide to Methanol Catalyzed by Ruthenium Cluster Anions in the Presence of Halide Anions
Authors: Tominaga Ken-ichi , Sasaki Yoshiyuki , Watanabe Taiki , Saito Masahiro 
Published: July 2006

Abstract
Methanol, together with methane, is formed for the first time by homogeneous hydrogenation of CO2 using a catalytic system consisting of Ru3(CO)12 and alkaline iodides in N-methylpyrrolidone (NMP) solution at 240 °C. The time course of the reaction indicates the successive formation of CO, methanol, and then methane. The FT-IR analysis of the resulting reaction solutions reveals the formation of several species of ruthenium carbonyl anion and their mutual interchanges during the reaction. A mechanism for the overall reaction is proposed, based on these results.
Determination of Chromium(III) and Chromium(VI) by Electrothermal Atomization Atomic-Absorption Spectrometry Following Coprecipitation with Gallium(III) Phosphate
Authors: Kagaya Shigehiro , Ueda Joichi 
Published: July 2006

Abstract
Gallium(III) phosphate coprecipitates quantitatively 0.2—7.5 μg of chromium(III) from 100 to 500 cm3 of a sample solution at pH 4.5—6.0. Although chromium(VI) is hardly coprecipitated with gallium(III) phosphate, it can be collected as chromium(III) after reduction by hydroxylamine. The calibration curve is linear from 8 to 300 ng cm−3 for chromium. The detection limit (signal/noise = 2) is 0.11 ng cm−3 of chromium(III) or chromium(VI) in 500 cm3 of the initial sample solution.
Dioxotungsten(VI) Complexes of ONO Donor Ligands and the X-Ray Crystal Structure of [WO2(o-OC6H4CH=NN=C(O)C6H5)(MeOH)]·MeOH
Authors: Maurya Mannar R , Antony Deena C , Gopinathan Sarada , Puranik Vedavati G , Tavale Sudam S , Gopinathan Changaramponnath 
Published: July 2006

Abstract
A general method for the preparation of dioxotungsten(VI) complexes of the type [WO2L(MeOH)] (where LH2 = the Schiff’s base derived from salicylaldehyde or o-vanillin and benzoylhydrazide, salicylhydrazide, furoylhydrazide, and isonicotinoylhydrazide) using [WO2(acac)2] (acacH = acetylacetone) as a precursor, is described. These complexes have been characterized by elemental analysis, electrical conductance, IR, electronic, and NMR spectral, electrochemical, and magnetic susceptibility measurements. The structure of [WO2(o-C6H4CH=NN=C(O)C6H5)(MeOH)]·MeOH (1a·MeOH) has been determined by single-crystal X-ray diffraction analysis. 1a·MeOH crystallizes in the space group Pbc21 with a = 6.992(2), b = 16.190(2), c = 31.390(4) Å, V = 3553.4(12) Å3, Z = 8, RF = 0.050, and Rw = 0.054. The tungsten atom has a highly distorted octahedral coordination in which anionic oxygen atoms of the tridentate ligand are mutually trans and are cis to the cis-dioxo group.
Kinetics and Mechanisms of the Vanadium(IV)-Catalyzed Oxidation of Iodide Ion in the Presence of Molecular Oxygen in an Acid Solution
Authors: Kimura Masaru , Hara Tomoko , Tsukahara Keiichi 
Published: July 2006

Abstract
The kinetics of the oxidation of iodide ion to iodine by molecular oxygen catalyzed by VO2+ ions were studied in sulfuric acid solutions in the dark. After an induction period during which time the I2−• radical anion forms, the rate of formation of iodine increased due to catalysis by VO2+ ions. The rate of reaction depended on the concentrations of VO2+, H+, and I−, and was independent of the ionic strength. The reaction was inhibited by either radical scavengers or the complex-forming substances of ethylenediaminetetraacetic acid and chloride ions. A chain mechanism containing I2−•/I2, VO2+/V3+, and O2/HO2• redox cycles is presented.
1,3-Dipolar Additions of a Nitrile Ylide with Carbonyl Compounds Studied by Laser Flash Photolysis of 3-(Biphenyl-4-yl)-2H-azirine
Authors: Naito Ikuo , Fujiwara Yoshihisa , Tanimoto Yoshifumi , Ishida Akito , Takamuku Setsuo 
Published: July 2006

Abstract
1,3-Dipolar additions of a nitrile ylide (NY) with carbonyl compounds were studied by means of the laser flash photolyses of 3-(biphenyl-4-yl)-2H-azirine in the presence of various types of carbonyl compounds: i.e. ketones, aldehydes, and esters. NY decays according to psuedo first-order kinetics. The rate constant of the 1,3-dipolar addition reaction of NY with carbonyl compound is increased with increasing the ionizing potential of the π-electron on the carbonyl double bond. NY reacts also with carbon dioxide (k = 5.3 × 105 dm3 mol−1 s−1 in acetonitrile).
Synthesis of dl-Shikonin by Vanadium(II)-Assisted Cross-Coupling and Electrooxidation of Aromatic Nuclei
Authors: Torii Sigeru , Akiyama Kouji , Yamashita Hidetoshi , Inokuchi Tsutomu 
Published: July 2006

Abstract
Vanadium(II)-assisted cross-coupling of 1,4,5,8-tetramethoxynaphthalene-2-carbaldehyde and 3-methyl-2-butenal was employed for introduction of the side chain of dl-shikonin. 2-(1-Hydroxy-4-methyl-3-pentenyl)-1,4,5,8-tetramethoxynaphthalene was prepared by the pinacol coupling and the subsequent palladium-catalyzed hydrogenolysis of the carbon–oxygen bond at the allylic position of the diol carbonate. Electrochemical oxidation of the 2-substituted 1,4,5,8-tetramethoxynaphthalene, followed by reductive acetylation with zinc and the subsequent electrooxidation of the resulting 5,8-diacetoxy-1,4-dimethoxynaphthalene, afforded the corresponding 5,8-diacetoxy-1,4-naphthoquinone, whose alkaline hydrolysis furnished dl-shikonin.
The Nucleophilic Substitution Reaction of p-Chloronitrobenzene with N-Substituted Cyclic Amines under High Pressure
Authors: Ibata Toshikazu , Shang Mu-Hong , Demura Tetsuo 
Published: July 2006

Abstract
An aromatic nucleophilic substitution (SNAr) reaction of p-chloronitrobenzene with N-substituted pyrrolidines under high pressure gave p-pyrrolidinonitrobenzene and ring-opening products through quaternary ammonium salt. The selectivity of dealkylation and ring-opening depends on the electronic and steric factors of N-substituents. The reactions with N-methylaziridine and N-methylazetidine gave ring-opening products without affording any demethylation product.
Preparation and Properties of Novel Titanio- and Zirconiosiloxane Compounds
Authors: Gunji Takahiro , Kitakatsu Tsutomu , Abe Yoshimoto 
Published: July 2006

Abstract
Syntheses and characterization of titaniosiloxane and zirconiosiloxane compounds were investigated. Titaniosiloxane and zirconiosiloxane compounds were prepared by the reaction of di-t-butoxymethoxysilanol [DBMS] with titanium or zirconium alkoxides.
DBMS was subjected to the reaction with bis(acetylacetonato)titanium diisopropoxide and titanium tetraisopropoxide to give titaniosiloxane compounds TS12 and TS14, respectively. Titaniosiloxane compounds were isolated by distillation or sublimation. TS12 was estimated to be cis-form from its 13C NMR spectrum in CDCl3. TS14 was stable in solution, but apt to decompose after isolation.
ZS12 and ZS14 were prepared by the reaction of DBMS with bis(acetylacetonato)zirconium diisopropoxide and zirconium tetraisopropoxide, respectively. The isolation of ZS12 and ZS14 by distillation or recrystallization was difficult because of decomposition and high solubility, and the formation of ZS12 and ZS14 was confirmed by 1H, 13C, and 29Si NMR and IR spectra.
Syntheses and Characterizations of Cyclotitanosiloxane and Cyclozirconosiloxane Compounds
Authors: Gunji Takahiro , Kasahara Takayuki , Fujii Akihiko , Abe Yoshimoto , Kawano Masaki 
Published: July 2006

Abstract
The syntheses and characterizations of cyclotitanosiloxane (CTS) and cyclozirconosiloxane (CZS) were investigated. CTS and CZS were synthesized by the reaction of di-t-butoxysilanediol with bis(acetylacetonato)diisopropoxidotitanium(IV) or bis(acetylacetonato)diisopropoxidozirconium(IV) in benzene. The formation of CTS and CZS was confirmed by the NMR and IR spectra and elemental analysis. The X-ray structural analysis for single crystals revealed that CTS and CZS consist of an eight-membered ring of two titano- or zirconosiloxane linkages bearing two t-butoxy groups on a silicon atom and two acetylacetonato groups on a titanium or zirconium atom.
Dianion Dialkali Metals of 2,2′,5,5′-Tetrasilabicyclopentylidene. Synthesis and Crystal Structures
Authors: Sekiguchi Akira , Ichinohe Masaaki , Kabuto Chizuko , Sakurai Hideki 
Published: July 2006

Abstract
The intramolecular bissilylation of 3,3,6,6,7,7,10,10-octamethyl-3,6,7,10-tetrasilacyclodecyne (4a) at 110 °C with a catalyst of Pd(OAc)2/1,1,3,3-tetramethylbutyl isocyanide under 5000 bar produced 2,2,2′,2′,5,5,5′,5′ -octamethyl-2,2′,5,5′-tetrasilabicyclopentylidene (5a). 2,2,2′,2′,5,5,5′,5′ -Octamethyl-2,2′,5,5′-tetragermabicyclopentylidene (5b) was also synthesized by the same method. The reaction of 5a with alkali metals (Li, Na, K, Rb, and Cs) in THF gave the corresponding dianion dialkali metals. The structures of 5a, (2,2,2′,2′,5,5,5′,5′-octamethyl-2,2′,5,5′-tetrasilabicyclopentylidene)bis[(tetrahydrofuran)lithium(I)] (6a), and (2,2,2′,2′,5,5,5′,5′-octamethyl-2,2′,5,5′ -tetrasilabicyclopentylidene)bis[(tetrahydrofuran)sodium(I)] (6b) were studied by X-ray crystallography as well as NMR spectroscopic means. The central anionic C–C bond is not twisted for 6a, whereas it is twisted by 17.1° for 6b.
Electrooxidative Fission of Carbon–Carbon Double Bond in a K2OsO2(OH)4/HIO4 Double Mediatory System
Authors: Tanaka Hideo , Kikuchi Ryo , Baba Masakatsu , Torii Sigeru 
Published: July 2006

Abstract
Electrooxidation of olefins in the presence of potassium osmate (0.04 molar amount) and periodic acid (0.5 molar amount) afforded the corresponding carbon–carbon double bond cleavage products in moderate to good yields, where the turnover number of periodic acid reached ca. 3.
Electrochemical Hydrotrifluoromethylation of Dialkyl Fumarates
Authors: Dan-oh Yasufumi , Uneyama Kenji 
Published: July 2006

Abstract
Dialkyl fumarates were electrochemically hydrotrifluoromethylated. The reaction was explained in terms of anodic bistrifluoromethylation and subsequent hydrolysis of one of the trifluoromethyl groups under the basic condition near cathode surface.
On the Nonradiative Decay of Individual Vibronic States
Authors: Islampour Reza , Gharanfoli Soheila 
Published: July 2006

Abstract
A general formulation of the nonradiative decay-rate constant of initially selected vibronic states in polyatomic molecules is developed. This method includes the effects of displacements as well as distortions of the potential-energy surfaces. The rate constant is also calculated perturbatively using the cumulant expansion technique. For a comparison of the two methods, a numerical analysis is carried out.
ESR Study of Paramagnetic Nickel Species Obtained by Reduction and Oxidation of Bis(1,3,5-triphenylformazanato)nickel(II)
Authors: Kawamura Yoshiko , Yamauchi Jun 
Published: July 2006

Abstract
Diamagnetic bis(1,3,5-triphenylformazanato)nickel(II) was reduced or oxidized by chemical and electrochemical methods. The paramagnetic Ni(I) and Ni(III) complexes thus obtained were studied by means of ESR spectroscopy. Ni(I) complexes formed by alkali metal reductions showed remarkable changes in their g values, depending on the kinds of alkali metal used. The change of g-values, which related to the ionic radii of the alkali metal ions, was well interpreted by the axial coordination effect due to the alkali metal ions. The electrochemical formation of the Ni(I) complex showed a solvent-dependency; the nickel(II) ion was reduced in DMF solution, but not in acetonitrile. The g-components were 2.030 for g// and 2.001 for g⊥. The relation between the two g-components gave a dx2−y2 ground state for the Ni(I) ion in the complex. Their anisotropy was very small. The Ni(II) ion oxidized by both chemical and electrochemical methods showed a dz2 ground state. The three g-components were 2.056, 2.039, and 2.000 in DMF, which are similar to those obtained from the other oxidation methods.
Synthesis and Crystal Structures of γ-Type Octamolybdates Coordinated by Chiral Lysines
Authors: Inoue Miyao , Yamase Toshihiro 
Published: July 2006

Abstract
The acidification of aqueous solutions containing Na2MoO4·2H2O in the presence of a chiral lysine ligand (d- and l-form) gives octamolybdates coordinating two lysine ligands, Na2[Mo8O26(d-lysH2)2]·8H2O (Mo8-d) and Na2[Mo8O26(l-lysH2)2]·8H2O (Mo8-l) (where lysH2 is 2,6-diammoniohexanoato), respectively. These two compounds crystallize with triclinic symmetry in the space group P1, the cell parameters being a = 10.782(2), b = 11.241(5), c = 10.027(2) Å, α = 93.21(2), β = 102.86(2), γ = 112.98(2)°, V = 1077(1) Å3, and Z = 1 for the Mo8-d, and a = 10.783(4), b = 11.246(3), c = 10.019(4) Å, α = 93.21(3), β = 102.75(3), γ = 112.98(2)°, V = 1077(2) Å3, and Z = 1 for Mo8-l. The X-ray crystal structures of these two species have been solved by the MITHRIL direct method and refined to R = 0.0337 and 0.0312 for Mo8-d and -l, respectively. The chiral lysine ligands are coordinated via their carboxylate-oxygen atoms at the vacant sites on the two five-coordinate molybdenum for the centrosymmetric γ-[Mo8O26]4− anion to retain their configuration with a resultant formation of optically-active octamolybdate species.
Multielement Determination of Rare Earth Elements in Coastal Seawater by Inductively Coupled Plasma Mass Spectrometry after Preconcentration Using Chelating Resin
Authors: Sawatari Hideyuki , Toda Takeshi , Saizuka Tomoo , Kimata Chisen , Itoh Akihide , Haraguchi Hiroki 
Published: July 2006

Abstract
Rare earth elements in coastal seawater were preconcentrated by using chelating resin in a batch method and determined simultaneously by inductively coupled plasma mass spectrometry (ICP-MS). In this procedure, matrix components (Na, K, Mg, and Ca) were eliminated to reduce matrix effects in ICP-MS analysis and rare earth elements were concentrated by a concentration factor of 100. The pH dependence of the recovery, resin amounts, amount of ammonium acetate for washing, and elution of adsorbed metals with nitric acid were examined in details to optimize the experimental conditions in sample pretreatment. All rare earth elements in coastal seawater were determined at the ppt or sub-ppt level successfully by the present analytical method.
Hydrazones Derived from Dithiamonoaza and Tetrathiamonoaza Analogs of Polyethers as Silver Ion Selective Ionophores: Syntheses, Proton-Dissociation Behaviors, and Metal Ion Complexing Properties in 1,4-Dioxane–Water Acidic Solution
Authors: Ishikawa Junichi , Sakamoto Hidefumi , Mizuno Tamao , Otomo Makoto 
Published: July 2006

Abstract
Cyclic and acyclic dithiamonoaza, tetrathiamonoaza, and tetrathiadiaza analogs of polyethers bearing a hydrazone moiety on nitrogen atom(s) were synthesized. Their acidity constants in 1,4-dioxane–water solution and stability constants of hydrazones derived from dithiamonoaza and tetrathiamonoaza analogs of polyethers for some heavy metal ions in same acidic media were measured spectrophotometrically. Hydrazones of cyclic and acyclic tetrathiamonoaza series had highly Ag+-selective complexability.
Low-Temperature Phosphorimetric Determination of Traces of Palladium(II) with Water-Soluble Coproporphyrin III
Authors: Endo Kazutoshi , Igarashi Shukuro 
Published: July 2006

Abstract
The characteristics of coproporphyrin III (Copro III) as a chelating agent, a chromogenic agent, and a luminescence agent for metal ions were studied. Copro III forms 1 : 1 complexes with Co(II), Cu(II), Mn(II), Ni(II), Pd(II), and Zn(II). Copper, palladium, and zinc complexes exhibit phosphorescence at liquid nitrogen temperature (77 K), and the intensity of the palladium complex (λPdmax = 659 nm) is 10 and 13 times larger than that of the copper and zinc complexes (λCumax = 685 nm, λZnmax = 702 nm), respectively. Based on these facts, a low-temperature phosphorimetric determination of the 10−8 mol dm−3 level of palladium was developed. The detection limit (S/N = 3 using a 150 W xenon arc lamp as a light source) was 8 × 10−9 mol dm−3, and the relative standard deviation was 2.8% for 6 × 10−7 mol dm−3 Pd(II) (7 determinations). Interference from many metal ions was avoided by selective extraction of palladium(II) as an ion-pair of the bromo complex with H2SO4-tetrabutylammonium bromide-methyl isobutyl ketone systems, followed by back extraction with acetate buffer solution (pH 5.0).