bluuebunny/crossref_metadata_2025_split huggingface dataset:
ortho-Disubstituted F-Benzenes. V. Intramolecular Heteroatom-facilitated ortho-Substitution of F-Benzene Derivatives with Oxazolinyl and Oxazinyl Groups
Authors: Inukai Yoshinari , Takuma Keisuke , Toritani Koji , Sonoda Takaaki , Kobayashi Hiroshi 
Published: July 2006

Abstract
The oxazinyl and oxazolinyl substituents on an F-benzene ring facilitated the substitution of fluorine ortho to the heterocyclic functional groups by carbon and nitrogen nucleophiles. Alkylmagnesium halides and alkyllithium compounds were employed as the carbon nucleophile, and lithium N-methylanilide and N-methylanilinomagnesium halide as the nitrogen nucleophile. The selective ortho-substitution was accomplished by the complexing interaction between the ring-membered nitrogen on the functional substituents and the anionic nucleophile through the interposing metal cation. Effects of the substituents in the orientations and rates of the reactions depended upon the polarity of the reaction solvent and the kinds of anionic nucleophile and counter metal cation.
Electronic Spectra of (DBTTF)3· SnBr6 Complex
Authors: Tanaka Masashi , Kamiya Kohji , Tanaka Jiro , Murata Shizuaki 
Published: July 2006

Abstract
The polarized reflection spectra of (DBTTF)3·SnBr6 complex have been measured and the absorption spectra have been determined by the simulation of the observed reflection spectra. The 4000 cm−1 band polarized parallel to the stacking axis has been assigned to the charge resonance(CR) band. The theoretical analysis of the electronic structure of (DBTTF)3·SnBr6 complex has been made for the explanation of the energy and absorption intensity of the CR band.
A Study on Some Simple and Mixed Ligand N,N-Disubstituted Dithiocarbamates of Thallium(III)
Authors: Soundararajan G , Subbaiyan M 
Published: July 2006

Abstract
Neutral tris (N,N-disubstituted dithiocarbamato) thallium (III) ((TI(III)) has been prepared from acyclic dimethylamine, diethylamine, dipropylamine, dibutylamine, N-methylaniline, dibenzylamine, and from piperidine. Mixed ligand dithiocarbamates were found to form by ligand exchange reactions while mixing the simple, symmetric chelates in nonpolar solvents and got separated on preparative TLC layers of silica gel. These chelates were characterised by elemental analyses, IR, 1H NMR, and electronic spectral studies.
The Reversibilities of the Adsorption and Desorption of Organic Compounds in Water
Authors: Urano Kohei , Kano Hisanao , Tabata Toshimasa 
Published: July 2006

Abstract
The reversibilities of the adsorption and desorption of seventeen organic compounds in water on a granular activated carbon and a polystyrene adsorbent were examined by means of a batch-adsorption method. The adsorptions of many organic compounds were reversible, but the adsorptions of several phenolic compounds and aniline were irreversible for the activated carbon, because these compounds were adsorbed strongly on the surface of activated carbon by the π-electron combination. On the other hand, the adsorptions of all the organic compounds were reversiible for the polystyrene adsorbent.
Oxygen Isotope Shifts in 17O NMR Spectra of the Uranyl Ion
Authors: Jung Woo-Sik , Ikeda Yasuhisa , Tomiyasu Hiroshi , Fukutomi Hiroshi 
Published: July 2006

Abstract
The 17O NMR spectrum of uranyl oxygens enriched with 17O gave three peaks. These peaks are assigned to the signals of three isotopomers, [16O=U=17O]2+, [17O=U=17O]2+, and [18O=U=17O]2+. Chemical shifts for the signals of [17O=U=17O]2+ and [18O=U=17O]2+ were −0.054±0.002 and −0.108±0.002 ppm relative to [16O=U=17O]2+, respectively.
Stereochemistry of Halogen-Metal Exchange Reaction of Vinyl Halide with Grignard Reagent
Authors: Sugita Toshio , Sakabe Yo-ichi , Sasahara Toshiaki , Tsukada Mitsunori , Ichikawa Katsuhiko 
Published: July 2006

Abstract
Halogen-magnesium exchange was confirmed to proceed with stereospecific retention of configuration in the reaction of β-bromostyrene and butylmagnesium bromide.
Reduction of Sulfonic Acids with Triphenylphosphine–Diaryl Disulfide System
Authors: Oae Shigeru , Togo Hideo 
Published: July 2006

Abstract
Diaryl disulfides are effective catalysts to reduce arenesulfonic acids with triphenylphosphine to the corresponding arenethiols in good yields, while alkanesulfonic acids are transferred into the corresponding alkyl aryl sulfides. Arenesulfonic acids bearing electron-donating substituents can be reduced more readily than those having electron-withdrawing substituents, while diaryl disulfides bearing electron-withdrawing substituents are more effective catalysts than diaryl disulfides with electron-donating ring substituents.
A Radical-induced Extrusion Reaction of 2-(Benzylsulfonyl)tropones to 2- and 4-Benzyltropones
Authors: Takeshita Hitoshi , Matsuo Norihide , Mametsuka Hiroaki 
Published: July 2006

Abstract
Several 2-(benzylsulfonyl)tropones were thermolized to give 2- and 4-benzyltropones. The radical mechanism for the thermolysis was elucidated by a deuterium-labelling experiment.
Photochemical Reactions of Spiro[benzo[b]thiophene-2(3H), 1′-cydopropan]-3-ones
Authors: Kamigata Nobumasa , Hagihara Koichi , Hashimoto Satoshi , Iizuka Hirokazu , Kobayashi Michio 
Published: July 2006

Abstract
The photolysis of spiro[benzo[b]thiophene-2(3H),1′-cyclopropan]-3-one 1,1-dioxide (1) in benzene afforded 2-biphenylyl cyclopropyl ketone with extrusion of sulfur dioxide, whereas the irradiation of 1 in toluene or p-xylene formed photoreduced dimer and bibenzyl or 4,4′-dimethylbibenzyl, respectively. The photolysis of spiro[benzo[b]thiophene-2(3H),1′-cyclopropan]-3-one in benzene afforded the valence isomer 2,3-dihydro[1]benzothieno[3,2-b]furan.
The Preparation of N-Protected Amino Alcohols and N-Protected Peptide Alcohol by Reduction of the Corresponding Esters with Sodium Borohydride. An Improved Procedure Involving a Slow Addition of a Small Amount of Methanol
Authors: Soai Kenso , Oyamada Hidekazu , Takase Masako 
Published: July 2006

Abstract
Esters of N-protected amino acids and an N-protected peptide were reduced selectively to the corresponding alcohols in high yields using lesser amounts of sodium borohydride than does the conventional method by the slow addition of methanol to the mixture of ester and NaBH4 in t-butyl alcohol or tetrahydrofuran at 50°C.
Kinetics of Solute-Solvent Interaction in Aqueous Solution of Butyl Carbitol by Ultrasonic Methods
Authors: Nishikawa Sadakatsu , Shibata Masayuki 
Published: July 2006

Abstract
Ultrasonic absorptions in the frequency range 4.5–220 MHz and sound velocities at 2.5 MHz were measured at 25 °C with aqueous solutions of Butyl Carbitol (diethylene glycol monobutyl ether) over the concentration range 0.497–3.00 mol dm−3. Only a single relaxational process was observed and attributed to a perturbation of the equilibrium AB\oversetk12\undersetk21↔A+B, where A is Butyl Carbitol as the solute and B is water as the solvent participating in the reaction. A data analysis has led to the estimates k12=3.4×107 s−1, k21=2.0×108 dm3 mol−1 s−1, the standard volume change of reaction ΔV°=0.32 cm3 mol−1, and the standard enthalpy change ΔH°=5.4 kJ mol−1. The effect of the hydrophobicity of solute molecules on the water structure is discussed by comparing the present results with previous ones for other aqueous nonelectrolyte solutions.
Optical Resolution of Pyridoxal-like Pyridinophanes
Authors: Tachibana Yoji , Komatsu Toshihiko , Ando Makoto , Kuzuhara Hiroyoshi 
Published: July 2006

Abstract
Racemic modifications of the pyridoxal-like ansa compounds such as 15-formyl-14-hydroxy-2,8-dithia[9](2,5)pyridinophanes prepared as a pontential catalyst for stereospecific nonenzymatic reactions were optically resolved through formation of Schiff bases by treatment with amino sugar derivatives or amino acids. Resolutions with the amino sugar derivatives were ascribable to the difference of the solubilities of the diastereomeric Schiff bases, whereas those with the amino acids resulted from the difference of the reaction rates for the formation of the diastereomeric Schiff bases. As the amino sugar resolving agents, 3-amino-3-deoxy-1,2:5,6-di-O-isopropylidene-β-d-idofuranose and the corresponding α-d-glucofuranose isomer were employed and gave (R)- and (S)-pyridoxal-like pyridinophanes, respectively. On the other hand, chiral valine was the most efficient resolving agent among the amino acid tested and the presence of half equimolar Fe3+ markedly increased the optical purities of the products. Employment of (S)-valine gave (R)-pyridinophanes in excess and vice versa.
Studies on the Inelastic Electron Tunneling Spectroscopy of o-Hydroxy-, o-Amino-, and o-Mercaptobenzoic Acid on Aluminium Oxide
Authors: Monjushiro Hideaki , Murata Katsuo , Ikeda Shigero 
Published: July 2006

Abstract
Inelastic electron tunneling (IET) spectra were obtained for o-hydroxybenzoic acid(OHBA), o-aminobenzoic acid (OABA) and o-mercaptobenzoic acid (OMBA) adsorbed on aluminium oxide (AlOx) grown on aluminium film and were analyzed by referring IR results. OHBA is adsorbed on AlOx with both two functional groups, carboxyl and hydroxyl radicals. In the case of OABA, the adsorption occurs mainly with carboxyl group and the interaction between amino group and AlOx is rather weak. Mercapto group of OMBA forms two kinds of hydrogen bonding, and a dissociated species on AlOx. These results indicate that the surface of AlOx used in this study is highly hydrated and hydroxyl groups on the oxide are reactive with the proton donating sites of the chemical species. IET spectra of o-fluoro- and o-chlorobenzoic acid were also observed for comparison.
The Acid-catalyzed Decomposition of Diazo Carbonyl Compounds. II. Synthesis of 2- or 5-Heteroatom-substituted Oxazoles
Authors: Ibata Toshikazu , Yamashita Tsuyoshi , Kashiuchi Makoto , Nakano Shyuji , Nakawa Hiroyuki 
Published: July 2006

Abstract
The BF3-catalyzed decomposition of m- and p-substituted α-diazoacetophenones in excess of methyl thiocyanate and ethyl thiocyanate gave the corresponding 2-methylthio-, and 2-ethylthio-5-aryloxazoles, respectively in good yields along with s-alkyl-n-aroylmethylthiocarbamates and α-ethoxyacetophenones. However, yields of 2-dimethylamino-5-aryloxazoles by the reaction of dimethylcyanamide with α-diazoacetophenones were poor. 5-Dimethylamino- or 5-alkoxy-4-aryl-2-methyloxazoles were prepared by the reaction of N,N-dimethyl-α-(p-nitrophenyl)diazoacetamide or alkyl aryldiazoacetates with nitriles. When ethyl phenyldiazoacetate or methyl p-chlorophenyldiazoacetate were used, ketazines of alkyl arylglyoxylates were obtained together with oxazoles.
The Chemistry of Substituted Norbornenes. Reactions of 5-Vinyl-2-norbornene and 5-Ethylidene-2-norbornene with Formic Acid
Authors: Inoue Yoshiharu , Tanimoto Fumio , Kitano Hisao 
Published: July 2006

Abstract
Addition of formic acid to 5-vinyl-2-norbornene(1) and subsequent hydrolysis afford 6-vinyl-exo-2-norbornanol(5) and 5-vinyl-exo-2-norbornanol(6). Similarly, from 5-ethylidene-2-norbornene(2) are formed 6-ethylidene-exo-2-norbornanol(14), 5-ethylidene-exo-2-norbornanol(15), and 6-ethyltricyclo[2.2.1.02,6]heptan-3-ol(16). The hydroboration of 2 also leads to the formation of 14 and 15. Thus, the vinyl- and ethylidene-exo-norbornanols, 5, 6, 14, and 15, and the corresponding endo-norbornanols, 9, 10, 21, and 22, have been synthesized. A structural analysis of these products by 13C NMR revealed that under certain conditions, the ethylidene group of 2 exerts a great influence upon the reactivity of the norbornenyl ring double bond. Moreover, the fact that 16 derived from the addition of formic acid to 2 consists of both exo- and endo-hydroxy epimers is inconsistent with the previous observations that the exo-isomer is generally the sole product in related systems.
Selective Protection of Carbonyl Groups by Taking Advantage of a Combination of Solid Support and Girard’s Reagent
Authors: Chihara Teiji , Waniguchi Erika , Wakabayashi Tamie , Taya Kazuo 
Published: July 2006

Abstract
Some Girard’s derivatives of 4-phenylbenzophenone were prepared in ethanol solution, in the presence of Amberlite IRC-50 as a catalyst. Supported samples of the derivatives were then prepared by addition of silica gel to the solution, followed by evaporation of the ethanol. The supported samples were reduced with lithium tri-t-butoxyhydroaluminate by being suspended in THF solution. Hydrolysis, followed by extraction of the product, yielded 4-acetyl-α-phenylbenzyl alcohol in an 80% selectivity. In the same way, 4-acetylbenzaldehyde yielded 1-(4-formylphenyl)ethanol in an 81% selectivity. Relatively unhindered carbonyl groups were preferentially protected. Utilization of Girard’s reagents was successfully made as a protecting reagent and also as an extracting reagent of carbonyl compounds.
A Stereocontrolled Total Synthesis of C-Nucleosides
Authors: Sato Tsuneo , Hayakawa Yoshihiro , Noyori Ryoji 
Published: July 2006

Abstract
A stereocontrolled, general synthesis of chiral C-nucleosides has been achieved through a common lactonic C-β-glycoside intermediate which is readily obtainable from non-carbohydrate materials. Osmium tetraoxide-catalyzed vic-dihydroxylation of 8-oxabicyclo[3.2.1]oct-6-en-3-one gives, after acetonidation, (1R*,5S*,6S*,7R*)-6,7-isopropylidenedioxy-8-oxabicyclo[3.2.1]octan-3-one as a single stereoisomer. Baeyer-Villiger oxidation of the ketone affords the key intermediate, 2-(2,3-O-isopropylidene-β-ribofuranosyl)acetic acid lactone. The optically pure lactone having the natural d configuration is obtained through optical resolution of the seco acid by the Pirkle’s method followed by relactonization. α-Aminomethylenation of the lactone with t-C4H9OCH[N(CH3)2]2 yields 2-(2,3-O-isopropylidene-β-d-ribofuranosyl)-2-(dimethylaminomethylene)acetic acid lactone, which undergoes base-assisted condensation with urea followed by deprotection to furnish naturally occurring pseudouridine. Analogously, construction of heterocycles using thiourea and guanidine converts the aminomethylene lactone to unnatural pyrimidine C-nucleosides, 2-thiopseudouridine and pseudoisocytidine, respectively. Showdomycin in natural form can be prepared by two schemes. One approach consists of ozonolysis of the α-dimethylaminomethylene lactone, Wittig reaction using (C6H5)3PCHCONH2, and acid hydrolysis. The second entry makes use of 2-(2,3-O-isopropylidene-)3-d-ribofuranosyl)acetic acid lactone as the intermediate, which is converted to 2-(2,3-O-isopropylidene-)8-d-ribofuranosyl)-2-furfurylideneaceticacid lactone by the aldol reaction with furfural and dehydration. Methanolysis of the furfurylidene lactone and t-butyldimethylsilylation are followed by ozonolysis, Wittig condensation with (C6H5)3PCHCON2, and hydrolysis to give the maleimide C-nucleoside. In addition, 6-azapseudouridine and 6-aza-2-thiopseudouridine are obtainable via intramolecular ring closures of the semicarbazone and thiosemicarbazone of methyl 2-(2,3-O-isopropylidene-β-d-ribofuranosyl)glyoxylate followed by deprotections, respectively. These overall transformations are accomplishable under complete stereochemical control.
Ozonization of Phenothiazine and Its Analogues
Authors: Matsui Masaki , Miyamoto Yoshihiko , Shibata Katsuyoshi , Takase Yoshimi 
Published: July 2006

Abstract
When phenothiazine and phenoxazine were ozonized in dichloromethane, the cation radicals and the ozonate anion radical were detected, whereas, in the ozonization of phenoxathiin and thianthrene, these radicals were not observed. Formation of these radicals was more favorable as greater was the polarity of the solvent and lower was the oxidation potential of the substrate. Ozonization of phenothiazine and phenoxazine in polar solvents was explained by the electron-transfer mechanism accompanied by the electrophilic ozone attack, and that of phenoxathiin and thianthrene by the electrophilic ozone attack alone.
Heat-stable Enterotoxin (STh) of Human Enterotoxigenic Escherichia coli (Strain SK-1). Structure-activity Relationship
Authors: Ikemura Haruo , Watanabe Hiroyuki , Aimoto Saburo , Shimonishi Yasutsugu , Hara Saburo , Takeda Tae , Takeda Yoshifumi , Miwatani Toshio 
Published: July 2006

Abstract
For examination of the structure-activity relationship of STh, five shorter analogs of STh lacking one to five N-terminal amino acid residues of STh were synthesized. The synthetic peptides were confirmed to have the same intramolecular disulfide linkages as those in native STh. These peptides caused fluid accumulation in the intestine of suckling mice at almost the same molar levels as that of native STh. The toxicities of these peptides were also neutralized by antisera raised against native STh. These results indicated that the toxic and antigenic sites of STh are both located in the amino acid sequence between the Cys residue at the 5th position from the N-terminus and the C-terminal Tyr residue.
The Reactions of Hydrogen and Deuterium Atoms with Four Ketenes
Authors: Umemoto Hironobu , Tsunashima Shigeru , Sato Shin , Washida Nobuaki , Hatakeyama Shiro 
Published: July 2006

Abstract
The rate constants of the reactions of hydrogen and deuterium atoms with four ketenes have been measured using a pulse radiolysis-resonance absorption technique. For hydrogen atoms, the temperature dependence was also examined in the range of 240–440 K. The rate constants were well expressed by these Arrhenius equations: k(H+ketene)=3.9×106exp(−975⁄T); k(H+methylketene)=74×106exp(−881⁄T); k(H+ethylketene)=4.4×106exp(−728⁄T); k(H+dimethylketene)=6.0×106exp(−773⁄T), in units of m3 mol−1 s−1. No isotope effect between H and D atoms could be observed except for the gas-kinetic-collision frequency.
Kinetics and Mechanism of the Oxidation of Alcohols by Pyridinium Fluorochromate
Authors: Bhattacharjee Manabendra N , Chaudhuri Mihir K , Dasgupta Himadri S 
Published: July 2006

Abstract
Pyridinium fluorochromate, C5H5NHCrO3F, oxidizes benzyl alcohol, ethanol, and cyclohexanol to benzaldehyde, acetaldehyde, and cyclohexanone, respectively. While each of the oxidation, studied in acetonitrile–nitrobenzene (1 : 1, v/v) medium, is first order with respect to the oxidant, the rate is almost independent of the substrate concentration. The reactions are catalyzed by acid, the acid-catalyzed reactions being very fast, precluded determination of their order in acid medium. The effects of temperatures and solvent compositions were studied and activation parameters evaluated. Probable mechanisms are discussed.
Polarized Raman and Infrared Spectra of 2-Chloro- and 2-Bromopyrimidines
Authors: Nakama Sekiichiro , Shimada Hiroko , Shimada Ryoichi 
Published: July 2006

Abstract
The polarized Raman and infrared spectra of 2-chloro- and 2-bromopyrimidines were studied. Assignments of the normal vibrations for these molecules were made on the basis of polarization behaviors of the Raman and infrared bands and also through the normal coordinate calculation.
Intramolecular Orbital Interactions in 6,6′-Bi(1,4-dithiafulvenyl) Studied by Photoelectron Spectroscopy
Authors: Kobayashi Tsunetoshi , Yoshida Zen-ichi , Awaji Hiroshi , Kawase Tokuzo , Yoneda Shigeo 
Published: July 2006

Abstract
Photoelectron spectra of tetrathiafulvalene (TTF) and 6,6′-bi(1,4-dithiafulvenyl) (BDTF) were measured and compared with each other. The first photoelectron spectral band of BDTF is only slightly shifted relative to that of TTF, though the BDTF molecule is lengthened compared with the TTF molecule by two sp2 carbon atoms. From the LCGO model orbital interaction analysis, this apparent anomaly is ascribed to the near cancellation of the effects of two main factors, the energy and the terminal atomic orbital coefficient differences between the central olefinic group π orbitals. Orbital interaction analysis as demonstrated in this work may be useful for molecular design, especially for orbital energy control.
Extraction of Uranium(VI) by Emulsion Liquid Membrane Containing 5,8-Diethyl-7-hydroxy-6-dodecanone Oxime
Authors: Akiba Kenichi , Takahashi Toshihiko , Kanno Takuji 
Published: July 2006

Abstract
Extraction of uranium(VI) by a liquid surfactant membrane has been studied. The stability of water-in-oil (w/o) emulsion dispersed in the continuous aqueous phase increased with an increase in surfactant concentrations and in the fraction of the organic phase in emulsion globules. Uranium(VI) in dilute acid solutions was extracted into (w/o) emulsions containing 5,8-diethyl-7-hydroxy-6-dodecanone oxime (LIX 63) as a mobile carrier and its concentration decreased according to [U]t=[U]o exp(−kobsdt). The apparent rate constants (kobsd) increased with an increase in carrier concentrations and in external pH values, while they were slightly dependent on the stripping acid concentrations. Uranium was transported and concentrated into the internal aqueous droplets. The final concentration of uranium in the external aqueous phase dropped to about 10−3 of its initial value.
Enthalpies of Transfer of Single Ions and Metal Complexes from Water to an Aqueous Dioxane Solution
Authors: Ishiguro Shin-ichi , Ohtaki Hitoshi 
Published: July 2006

Abstract
Enthalpies of solution of some 1:1 and 2:1 electrolytes were determined in water and in a dioxane–water mixture (the dioxane content; 0.2 mole fraction or 55.0% w/w) by calorimetry at 25 °C. Enthalpies of transfer (ΔHto) of single ions from water to the dioxane–water mixture were obtained by employing the extrathermodynamic tetraphenylarsonium tetraphenylborate (TATB) assumption. Enthalpies of transfer of nickel(II) and copper(II) complexes with glycinate (gly−) and ethylenediamine (en) were also evaluated for [Ni(gly)n](2−n)+ (n=1–3), [Ni(en)n]2+(n=1–3), and [Cu(en)n]2+ (n=1–2) by combining enthalpies of transfer of the relevant single metal ions and ligands with enthalpies of complex formation reactions M+nL=MLn (M=Ni2+ or Cu2+ and L= gly− or en) in water and in the mixture. The enthalpies of transfer of the metal complexes examined here increased almost linearly with an increase in the number of the ligands within the complexes. The values of ΔHto of the ethylenediamine complexes of nickel(II) and copper(II) ions were all negative, as well as those of free Ni2+ and Cu2+ ions. On the other hand, the enthalpies of transfer of the noncharged [Ni(gly)2] and anionic [Ni(gly)3]− complexes were positive, while that of the [Ni(gly)]+ complex was still negative. The result suggested that hydration of the ligands coordinating to the central metal ions plays an essential role in the enthalpies of transfer of the metal complexes from water to the dioxane–water mixture.
X-Ray Structural Study on Molecular Stereochemistries of Six-coordinate Zn(II) Complexes of trans-ZnX2N4 Type. Out-of-plane Displacement of Zn(II) from a Plane Formed by In-plane Four Nitrogens
Authors: Ito Tasuku , Kato Masako , Ito Haruko 
Published: July 2006

Abstract
Molecular structures of trans-bis(isothiocyanato)(1,4,8,11-tetraazacyclotetradecane and 1,4,8,12-tetraazacyclopentadecane)zinc(II) complexes, [Zn(NCS)2(C10H24N4)] (1) and [Zn(NCS)2(C11H26N4)] (2), have been determined by X-ray analyses. Crystal data are: for 1, orthorhombic, space group P21nb, a=14.502(2), b=18.163(2), c=6.552(1) Å, V=1718.0(4) Å3, Z=4; for 2, monoclinic, space group P21/a, a=14.453(2), b=14.436(1), c=9.213(1) Å, β=104.82(1)°, V=1858.3(4) Å3, Z=4. Coordination geometries about Zn(II) in 1 and 2 are of the pseudo-octahedral type with two NCS groups at the trans positions, but the Zn(II) ion in each compound deviates from a plane defined by the four nitrogens of the macrocyclic ligand by 0.179 Å on the average in 1 and 0.193 Å in 2. Structural features of 1 and 2 suggest, complemented with data reported previously for out-of-plane Zn(II) structures, that potential surface regarding the out-of-plane displacement is very flat. The Zn–NCS distance has been found to decrease as an in-plane Zn–N length (or cavity size of the ligand) increases. The observed negative correlation is substantially stronger than those for Ni(II) and Co(III) complexes and discloses the softness of a Zn(II) ion.