bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Moderation and Tunneling Reaction of Recoil T Atoms in Solid Xenon–Hydrogen Mixtures at 77 K
Authors: Fujitani Yoshiteru , Miyazaki Tetsuo , Fueki Kenji , Masaki Nobuyuki M , Aratono Yasuyuki , Saeki Masakatsu , Tachikawa Enzo 
Published: July 2006

Abstract
Recoil T atom reactions were studied in Xe–H2–D2 mixtures at 77 K. The isotope effect on the T-atom reaction with H2 and D2 (k(T+H2→HT+H)/k(T+D2→DT+D)) was measured on the basis of the HT and DT yields. The isotope effect (k(T+H2)/k(T+D2)) is 1.1 in the range of hydrogen concentrations of 0.1–1.0 mol%. Since the small isotope effect (1.1)is similar to the isotope effect (1.0) for a hot T-atom reaction in the gas phase, recoil T atoms are not thermalized at these concentrations in solid xenon and form HT and DT by means of hot-atom reactions. At concentrations of hydrogen of less than 0.1 mol%, the recoil T atoms are thermalized before they encounter the solute hydrogen. The isotope effect increases with a decrease in the hydrogen concentration and amounts to 3.1 at a hydrogen concentration of 0.01 mol%. Since a large isotope effect is expected for the tunneling reaction of T atoms, the large isotope effect (3.1) at 0.01 mol% hydrogen was interpreted in terms of the tunneling reaction of thermalized T atoms. The present results in the solid xenon–hydrogen mixtures were compared with those in the gaseous xenon–hydrogen mixtures reported previously. It was concluded that hot T atoms in the solid xenon at 77 K are deactivated much less effectively than in the gas phase and that they migrate long distances with excess kinetic energies.
Polarized Raman and Infrared Spectra of 1,2,3- and 1,3,5-Trichloro- and Tribromobenzenes
Authors: Sakamoto Hironobu , Yoshikai Kazumasa , Maruyama Takao , Nibu Yoshinori , Shimada Hiroko , Shimada Ryoichi 
Published: July 2006

Abstract
Assignment of the normal vibrations of 1,2,3- and 1,3,5-trichloro- and tribromobenzenes was made through the vibrational analyses of the polarized Raman and infrared spectra and also through the normal coordinate calculation. Substitutional effect on the vibrational frequencies and modes of the hydrogen bending and wagging vibrations induced by the halogen atoms is discussed.
The Square Planar-Octahedral Equilibrium of Bismacrocyclic Ni(II)Ni(II) and Cu(II)Ni(II) Complexes with Polymethylene Bridges of Various Lengths
Authors: Mochizuki Katsura , Iijima Asako , Endoh Yumiko , Ikeda Yoshihito 
Published: July 2006

Abstract
Bismacrocyclic Ni(II)Ni(II) and Cu(II)Ni(II) complexes, i.e., 7,7′-polymethylenebis[2,12-dimethyl-3,7,11,17-tetraazabicyclo[1 1.3.1]heptadeca-1(17),2,11,13,15-pentaene]dinickel(II) perchlorates and 7,7′-polymethylenebis[2,12-dimethyl-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-l(17),2,11,13,15-pentaene]copper(II)nickel(II) perchlorates with polymethylene bridges 2–6-C long, were found to exist in an equilibrium between square planar and octahedral Ni(II) ions in water. The equilibrium constants and the thermodynamic parameters, ΔH and ΔS, for the Cu(II)Ni(II) complexes were evaluated on the basis of the analyses of the temperature-dependent absorption spectra. The formation of octahedral species was found to be exothermic; this reflects the predominant contribution of an exothermic change to the formation of Ni(II)–water bonds. The absolute values of ΔS corresponding to those expected for the liberation of two molecules of water are not in conflict with the equilibrium proposed. For both the Ni(II)Ni(II) and Cu(II)Ni(II) complexes, the equilibrium shifts toward the octahedral side as the polymethylene bridge is shortened.
Addition of a Sulfonamidyl Radical to Unsaturated Aromatic and Aliphatic Hydrocarbons
Authors: Miura Yozo , Ohnishi Tetsuya , Kinoshita Masayoshi , Kinoshita Takamasa 
Published: July 2006

Abstract
The reaction of Nphenylsulfonyl-3,5-di-t-butylphenylaminyl radical (2) with unsaturated aromatic and aliphatic hydrocarbons has been carried out in degassed benzene at 75°C. The reactions of 2 with unsaturated aromatic hydrocarbons gave 1:1, 1:2, and 2:1 adducts of 2 and the hydrocarbons in fair to good yields. On the other hand, in the reactions of 2 with unsaturated aliphatic hydrocarbons, hydrogen-abstraction by 2 from the hydrocarbons was the major reaction. In the reaction with 2-methylpropene, a product indicating the addition of 2 to 2-methylpropene was isolated in a 16% yield. On the basis of these results the reactivity of 2 is discussed and compared with that of structurally related N(4-chlorophenylthio)-3,5-di-t-butylphenylaminyl radical.
A Cyclopropane Sliding Reaction of Δ3-Africen-10-yl Cation
Authors: Hayano Kiyoharu , Shirahama Haruhisa , Matsumoto Takeshi 
Published: July 2006

Abstract
Rearrangement of Δ3-africen-10-yl cation, generated by the treatment of 10β-chloro-Δ3-africene with silica gel, accompanied cyclopropane sliding.
Molecular Complex of a Cationic Porphyrin and p-Nitrophenol. Verification of the Porphyrin Dimerization
Authors: Kano Koji , Hashimoto Shizunobu 
Published: July 2006

Abstract
Complexation between 4,4′,4″,4'″-(21H,23H-porphine-5,10,15,20-tetrayl)tetrakis[1-methylpyridinium] chloride (TMPyP) and p-nitrophenol has been studied in water. Upon the addition of p-nitrophenol, the coalesced fluorescence Q bands of TMPyP are resolved into well-separated Q(0–0) and Q(0–1) bands and the fluorescence decay comes to involve two exponential components. These results can be explained by the dimer model of TMPyP.
Bis(ferrocenecarbothioyl) Sulfide. Synthesis and Characterization
Authors: Kato Shinzi , Fukushima Tetsuaki , Ishihara Hideharu , Murai Toshiaki 
Published: July 2006

Abstract
Bis(ferrocenecarbothioyl) sulfide 1 was synthesized and characterized. The sulfide 1 was found to serve as an efficient ferrocenecarbothioylating reagent for amines, alcoholates, thiolates, and selenolates.
XPS Study of Bis(1,2-diaryl-1,2-ethylenedithiolato)nickels
Authors: Shiozaki Hisayoshi , Nakazumi Hiroyuki , Morikawa Tsutomu , Sato Yukihiro , Kitao Teijiro 
Published: July 2006

Abstract
The binding energies of S 2p and Ni 2p of the bis(1,2-diaryl-1,2-ethylenedithiolato)nickels were measured by means of X-ray photoelectron spectroscopy using a silicone oil as a reference. The results indicated that a reasonable correlation exists between Hammett substituent constants σp on phenyl group in the nickel complexes and the binding energy and between charge of complexes and the binding energy.
Synthesis of Several New Pyridazines and 3,5-Diarylanilines
Authors: Sadek Kamal Usef , Selim Maghraby Ali , Abdel-Motaleb Ramadan Maawad 
Published: July 2006

Abstract
Several new pyridazines and 3,5-diarylanilines were obtained from (1-arylethylidene)malononitriles 1b–e as starting compounds.
Divalent Metal Ion-Mediated Phosphodiester Bond Formation from Adenosine-5′-phosphorimidazolide with Glycolic Acid or Lactic Acid in Aqueous Solution. A Nonenzymatic Model Reaction for Nucleotidyl Transfer
Authors: Sawai Hiroaki 
Published: July 2006

Abstract
Some divalent metal ions mediated in phosphodiester bond formation from adenosione-5′-phosphorimidazolide (ImpA) and glycolic acid or lactic acid giving glycolyl adenylate or lactyl adenylate. The effect of divalent metal ions on this reaction was in the order: Pb2+&gt;Ni2+&gt;Co2+&gt;Zn2+&gt;Cu2+&gt;Mn2+&gt;Ca2+&gt;Mg2+&gt;none&gt;Hg2+. The metal ions promoted the reaction orienting the substrates and increasing the nucleophilicity of the hydroxy group of α-hydroxy acid by coordination. On the other hand, very little or no phosphodiester bond formation took place from ImpA and 3-hydroxypropionic acid or 4-hydroxybutyric acid in the presence of metal ions.
A Time-Resolved Photoacoustic Method with Pulsed Laser Excitation in the Condensed Phase: The Relation between Signal Intensity and Decay-Rate Constant
Authors: Terazima Masahide , Azumi Tohru 
Published: July 2006

Abstract
The photoacoustic signal magnitude in the condensed phase with a piezoelectric transducer and a pulsed laser is theoretically calculated for various quantum yield of the triplet formation (φisc) and decay rate constants from the triplet state. The results show that the φisc value and the triplet lifetime can be determined from the PA signal intensity.
Magnetic Properties of Molybdenum(IV) Trinuclear Coordination Compounds, Ba[Mo3O3S(Hnta)3]·10H2O and Cai1.5[Mo3S4(Hnta)2(nta)]·12H2O
Authors: Kobayashi Hanako , Shibahara Takashi , Uryû Norikiyo 
Published: July 2006

Abstract
The magnetic susceptibilities of two molybdenum(IV) trinuclear coordination compounds with cores [Mo3(μ3-S)(μ-O)3] and [Mo3(μ3-S)(μ-S)3] were measured in the temperature region from liquid He to room temperature. They had some extra diamagnetic susceptibilities in addition to the calculated values which have been discussed in anticipation of mesoscopic electronic devices.
Homocoupling of Aryl Halides Using Nickel(II) Complex and Zinc in the Presence of Et4NI. An Efficient Method for the Synthesis of Biaryls and Bipyridines
Authors: Iyoda Masahiko , Otsuka Hiroki , Sato Koichi , Nisato Nobue , Oda Masaji 
Published: July 2006

Abstract
Reduction of NiX2(PPh3)2 with zinc in the presence of Et4NI gives a nickel catalyst which has been proven to be useful for the coupling of aryl halides. This nickel catalyst can be prepared in THF without an additional triphenylphosphine and is effective for the homocoupling of aryl chlorides, bromides, and iodides to produce biaryls and bipyridines in good yields. The reported new approach provides a simple access to novel derivatives of biaryls and bipyridines.
η3-Allyl(methyl)platinum(II) Complexes. Synthesis, Conversion into η1-Allyl Complexes, and Electrochemical Behavior in Comparison with Thermolysis
Authors: Suzuki Takeshi , Ueda Michihisa , Koumoto Ryuhei , Nakamura Yukio 
Published: July 2006

Abstract
Complexes of the type [Pt(η3-allyl)Me(L)] (1) (allyl=C3H5, 1-MeC3H4, or 2-MeC3H4; L=tertiary phosphine) as well as [Pt(η3-C3H5)Bu(PPh3)] have been synthesized and characterized by NMR (1H, 13C) and mass spectroscopy. By the reaction with bidentate tertiary phosphines (L–L), [Pt(η3-C3H5)Me(PPh3)] (1b) was converted into η1-allyl complexes of the type [Pt(η1-C3H5)Me(L–L)]. With PPh3, cis-[Pt(η1-C3H5)Me(PPh3)2] was isolated. The reaction of 1b with neat 2,4-pentanedione (Hacac) afforded [Pt(acac)Me(PPh3)]. Complexes 1 thermally decompose in the solid state and in diphenylmethane solely giving propylene and methane, but the allyl-alkyl coupling reaction to form 1-butene is promoted by the addition of maleic anhydride. A similar coupling-promoting effect was observed in the electrochemical oxidation of 1b in THF at 23°C without additive. By taking into account the one-electron oxidation and the participation of the PPh3 ligand in its oxidation process, a possible mechanism of this electrochemically promoted coupling is proposed.
NAD (P)+-NAD (P)H Models. 69. Mechanism of Stereospecific (NET) Hydride Transfer Controlled by Electronic Effect
Authors: Ohno Atsuyoshi , Ogawa Masahiko , Mikata Yuji , Goto Mutsuo 
Published: July 2006

Abstract
The enantiotopic C4-hydrogen in Me3MQPH is abstracted stereospecifically by certain oxidizing reagent such as metal ions and quinones. The stereospecificity depends on the reactivity of the oxidizing reagent. Namely, in the oxidation with Fe(III) or Co(III) ion, a Brønsted-like correlation is observed between the specificity and pKa of amine added to the reaction system, whereas the stereospecificity of the oxidation with quinones is not affected by amine. The mechanism of this electronically controlled stereospecificity is discussed.
Reaction of Trimethylsilyl Isoselenocyanate with Oxiranes and Oxetane
Authors: Sukata Kazuaki 
Published: July 2006

Abstract
The reaction of trimethylsilyl isoselenocyanate with oxiranes and oxetane gave 2-trimethylsiloxyalkyl selenocyanates and 3-trimethylsiloxypropyl selenocyanate, respectively, in good to excellent yields. Effects of solvents and catalysts on regioselectivity were examined.
Peparation of New Nitrogen-bridged Heterocycles. 21. A Facile Synthesis of 2-Indolizinethiols Using New Protecting Groups
Authors: Kakehi Akikazu , Ito Suketaka , Yamada Naoaki , Yamaguchi Kiminobu 
Published: July 2006

Abstract
Some indolizine derivatives having (2-cyanoethyl)thio or (2-ethoxycarbonylethyl)thio group at the 2-position were prepared in moderate to good yields starting from the corresponding pyridinium 1-(thiocarbonyl)methylides. The treatment of these indolizines with a strong base such as potassium t-butoxide in N,N-dimethylformamide (DMF) gave smoothly title compounds, 2-indolizinethiols, with the elimination of acrylonitrile or ethyl acrylate.
Intermediates Formed in the Reaction of Benzenethiol or t-Butylthiobenzene with Ethyl Benzoylacetate in Polyphosphoric Acid
Authors: Nakazumi Hiroyuki , Watanabe Shigeru , Kitaguchi Tohru , Kitao Teijiro 
Published: July 2006

Abstract
The reaction of benzenethiol with ethyl benzoylacetate in polyphosphoric acid (PPA) at low temperature gave mainly ethyl 3-phenyl-3,3-bis(phenylthio)propionate 8 as an intermediate in the synthesis of thioflavones, while that from t-butylthiobenzene under similar conditions gave ethyl 3-(phenylthio)cinnamate 7 as a major product and many by-products. The reaction constant for intramolecular cyclic condensation of 7 in 98% sulfuric acid was −0.46 and −0.54 using Hammett substituent constants, σm and σm+, respectively. It is suggested that the increase of electron density at the ring closure site of the benzenethiol moiety of 7 promotes this ring closure reaction.
Thermal Decompositions of CH3I and CD3I. Experimental and Theoretical Approaches to the Specific Rates at the High Pressure Limit
Authors: Kodama Sukeya , Ooi Yasuhiro 
Published: July 2006

Abstract
The rate constants on the thermal decompositions of CH3I and CD3I at the high pressure limit, kd∞, were evaluated from the decomposition rates, measured as functions of the reaction time and the pressure of methyl iodide. The values of kd∞(CH3I) at 606.8, 620.2, 633.5, and 649.5 K were 2.92, 8.22, 22.0, and 68.2×10−6 s−1, respectively. The values of kd∞(CD3I)/kd∞(CH3I) were 0.290 at 620.2 K, 0.285 at 633.5 K, and 0.279 at 649.5 K. Meanwhile, the calculations for kd∞ were carried out using a rate theory derived from the assumption that the zero point energy and the vibrational energy are concerned in the entropy term of kd∞. From good correspondence between the experimental and calculated values, the values of D0 (chemical bond dissociation energy)=243.7, ΔE0 (energy change at 0 K)=230.6, and ΔH298° (enthalpy change at 298 K)=236.3 kJ mol−1 were obtained for the CH3–I bond dissociation. On the decomposition of equimolar mixture of CH3I and CD3I at 633.5 K and 10.67 kPa of the total pressure, it was found that the initial rate ratio of R^°(CH4+CH3D)/R°(CD4+CD3H) is 1.94 and the excitations to the active molecules of CH3I and CD3I in the mixture are less effective than those in the separated systems of CH3I and CD3, respectively.
Liquid Crystalline Properties of Alkyl 4-[4-(4-Methoxybenzoyloxy)benzylideneamino]benzoates and 4-[4-(4-Methoxybenzylideneamino)benzoyloxy]benzoates
Authors: Matsunaga Yoshio , Matsuzaki Hiroyuki , Miyajima Nobuhiko 
Published: July 2006

Abstract
The mesomorphic properties of homologous series of alkyl 4-[4-(4-methoxybenzoyloxy)benzylideneamino]benzoates and the isomeric compounds, 4-[4-(4-methoxybenzylideneamino)benzoyloxy]benzoates have been studied, employing thirty ester alkyl groups. The nematic phase appearing in the former series is thermally more stable than that in the latter: even the t-butyl and 1,1-dimethylpropyl esters are nematogenic. The mesophases in these esters are significantly promoted relative to those in the isopropyl and 1-methylpropyl esters, respectively. An alternation in the thermal stability of the nematic phase occurs when the branching methyl group is moved progressively to the penultimate carbon of the chain in both series. In the second series, the stabilization of the smectic A phase by 3- or 4-methylation is observed for both butyl and pentyl esters.
Some Mechanochemical Considerations on the Numbers of Spins Induced by Ultraviolet Light
Authors: Kashiwagi Hiroshi , Inoue Masami 
Published: July 2006

Abstract
The number of spins/g (NOS) generated in a binary powder of glycolic acid and silica–alumina (SA) increased during ultraviolet (UV) irradiation. After stopping illumination, the NOS value was found to decrease up to a constant number of sping/g (CNS), which was remarkably greater than the NOS value obtained before UV irradiation. The CNS values, thus obtained, were influenced not only by the calcination temperature of SA (Tea) and by the atmosphere of storage, but also by the duration of UV irradiation (DI). The values of CNS obtained at a low Tca (below 400°C) were also influenced by the time interval between stopping shaking and the start of UV irradiation (ti). Values of NOS having attained CNS remained unchanged for a long period, but finally began to decrease. The duration of CNS (DCNS) was also affected by Tca, the atmosphere of storage, DI, and ti DCNS decreased when CNS increased, and became unchanged when CNS reached a constant value. Values of CNS and DCNS induced by UV light were also influenced by the size of SA particles and by the mechanical energy given by shaking or compressing. Such mechanochemical effects are available, at least for studying the generation mechanism of UV-induced surface activity, for an improvement of the reproducibility of physicochemical data obtained during or after UV irradiation, and for the method of obtaining materials of constant efficiency.
Stereochemical Control in Microbial Reduction. 12. (S)-4-Nitro-2-butanol as a Source to Synthesize Natural Products
Authors: Nakamura Kaoru , Kitayama Takashi , Inoue Yoshihiko , Ohno Atsuyoshi 
Published: July 2006

Abstract
(S)-(+)-4-Nitro-2-butanol (1) obtained by the stereoselective reduction of 4-nitro-2-butanone by bakers’ yeast was employed for the syntheses of natural products. A precursor of (+)-brefeldin A is synthesized starting from this chiral building block by 10 steps short-cut procedure compared with the shortest method so far reported. (S)-(+)-Sulcatol is obtained in much better enantiomeric purity than those reported. The reactivity of 1 in base-catalyzed condensations with Michael acceptors or aldehydes is largely affected by a base employed as the catalyst.
Effect of Charge Density on the Cooperative Binding Isotherm of Surfactant Ion to Polyelectrolyte
Authors: Satake Iwao , Takahashi Toshi , Hayakawa Katumitu , Maeda Tamaki , Aoyagi Makoto 
Published: July 2006

Abstract
The binding isotherm of dodecyltrimethylammonium ion to partially hydrolyzed poly(potassium vinyl sulfate) was determined potentiometrically as a function of the average separation (d) between neighboring ionic groups. The cooperativity in binding process was found to decrease rapidly to about d≈0.44 nm and eventually disappear at d≈3.7 nm.
Coordination Selectivity in the Fe(II) Complex with 8-Hydroxy-7-[(2-hydroxy-5-carboxyphenyl)azo]-5-quinolinesulfonic Acid
Authors: Bai Zhi-Ping , Einaga Hisahiko , Hidaka Jinsai 
Published: July 2006

Abstract
The coordination of the title ligand (hcqs) to Fe(II) has been studied on the basis of its electronic absorption spectral characteristics, equilibrium, and stopped-flow kinetics in comparison with those of the related ligands. The bifunctional hcqs coordinates to Fe(II) not with a quinolinol (O–N) moiety, but selectively with a dihydroxyazo (O–N–O) one. The reaction mechanism of hcqs with Fe(II) and the thermodynamic stability of the complex are also discussed.
Photochemical Reaction of 1,3-Diketones. Transformation of 2-Benzoyl-2-methylcyclohexanones to 4-Benzoyl-2-methylcyclohexanones
Authors: Hasegawa Tadashi , Nishimura Michiko , Kodama Yukio , Yoshioka Michikazu 
Published: July 2006

Abstract
Upon irradiation, 2-benzoyl-2-methylcyclohexanone gave 4-benzoyl-2-methylcyclohexanone via Type II cyclization and a subsequent ring opening in 79% yield, whereas 2-benzoylcyclohexanone gave only the Type II elimination product. 2-Benzoyl-2-methyl-1-tetralone also underwent phototransformation to 4-benzoyl-2-methyl-1-tetralone.
Halogenation Using Quaternary Ammonium Polyhalides. XXIV. Chlorination of Acetanilides with Benzyltrimethyl ammonium Tetrachloroiodate
Authors: Kajigaeshi Shoji , Shinmasu Yoichi , Fujisaki Shizuo , Kakinami Takaaki 
Published: July 2006

Abstract
The reactions of acetanilides with a calculated amount of benzyltrimethylammonium tetrachloroiodate in acetic acid at room temperature or at 70°C gave, selectively, the desired chloro-substituted acetanilides in good yields.
Chromatographic Optical Resolution on 3,5-Disubstituted Phenylcarbamates of Cellulose and Amylose
Authors: Okamoto Yoshio , Aburatani Ryo , Hatada Koichi 
Published: July 2006

Abstract
3,5-Difluorophenylcarbamates and 3,5-bis(trifluoromethyl)phenylcarbamates of cellulose and amylose were prepared and used as chiral stationary phases for high-performance liquid chromatography to resolve optical isomers. Their optical resolving abilities were compared with those of 3,5-dimethylphenylcarbamates and 3,5-dichlorophenylcarbamates of the polysaccharides. 3,5-Difluorophenylcarbamates afforded practically useful columns.
The Thermal Decomposition of Ammonium Zinc Trihydrogenbis(phosphate) Monohydrate (NH4)ZnH3(PO4)2·H2O
Authors: Takenaka Atsushi , Hieda Tsuyoshi , Kimura Koji , Motooka Itaru , Nariai Hiroyuki 
Published: July 2006

Abstract
(NH4)ZnH3(PO4)2·H2O[NZHP] was prepared by a wet method. NZHP was gradually decomposed to di-(P2) and oligophosphates (n=3–9: Poligo). A part of the formation of Poligo involved hydrolysis of the –P–O–P– linkages of P2, which was accerelated by humidity. γ-Zn2P2O7 partially crystallized from P2. Above 350°C, NZHP was changed to long-chain β-Zn(PO3)2.
Dehydrogenation of Hydroaromatic Components in Coal-Derived Hydrocarbons for Structural Analysis
Authors: Sugimoto Yoshikazu , Miki Yasuo , Oba Masaaki , Yamadaya Shoko 
Published: July 2006

Abstract
The dehydrogenation technique was evaluated by using several cyclic hydrocarbons, and was successfully used to convert hydroaromatic components in coal-derived nonpolar fractions into the corresponding aromatic compounds.
Ni(II) Complexes of N,N′-Ethylenebis(o-mercaptobenzamide): A Quadridentate Thiolato Amide {S2N2} Ligand
Authors: Yamamura Takeshi , Tadokoro Makoto , Nakamura Nobuhumi , Tanaka Koji , Asakura Kiyotaka 
Published: July 2006

Abstract
Three nickel(II) complexes with N,N′-ethylenebis(o-mercaptobenzamide), H4ebtsa, a quadridentate {S2N2} ligand classified as a PAC (polyanionic chelating) ligand, were isolated. Although they were different in their apparent charges, their coordination units were revealed to be equal from their physicochemical behavior. They will be described as Ni(H2ebtsa). EXAFS and XANES study was undertaken for one of the new compounds, and the results were compared with those for similar three NiS2N2 complexes, (N,N′-ethylenebis(o-mercaptobenzylidenaminato))Ni(II), (N,N′-ethylenebis(o-mercaptobenzylaminato))Ni(II) and (NEt4)[Ni(SPh)4]. From these results and a comparison with the results for [Ni(ebtsa)]2, it was concluded that a square planar {S2N2} unit was reliable as the coordination sphere of Ni(H2ebtsa). The character of the amide proton in the coordination unit was also studied.