bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catalytic Hydrogasification of a Carbon Material with Dodecacarbonyltriiron(0) and Iron(iii) Nitrate: Effects on Surface Area, Pore Structure, and Hydrogen Adsorption
Authors: Arai Masahiko , Nishiyama Yoshiyuki 
Published: July 2006

Abstract
The catalysis of adsorbed dodecacarbonyltriiron(0) was used to develop the pore structure of a carbon through its partial gasification with hydrogen. The catalytic gasification at 500 °C increased the volumes of pores, in particular those of 3–5 nm in diameter. In contrast, such an effect was not observed when iron(III) nitrate was used as a catalyst. The adsorbability of hydrogen on carbon-supported iron particles obtained after gasification was examined by temperature-programed desorption (TPD). The TPD spectrum of hydrogen, in particluar, at temperatures above 200 °C, for a cluster-derived sample differed from that for a nitrate-derived sample. In addition, the apparent activation energy for the desorption of hydrogen in a low-temperature peak at around 90 °C for the former sample was larger than that for the latter. Heat treatments caused the TPD characteristics of the cluster-derived sample to become very similar to those of the nitrate-derived sample.
Stereoselective Isomerization Reactions of the (Ethylenediamine-N,N′-diacetato)(ethylenediamine)cobalt(III) and (Ethylenediamine-N,N′-diacetato)(glycinato)cobalt(III) Complexes in a Basic Aqueous Solution
Authors: Kawaguchi Hiroshi , Uchiyama Naomi , Ama Tomoharu , Yasui Takaji 
Published: July 2006

Abstract
Isomerization reactions of the [Co(edda)(en)]+ and [Co(edda)(gly)] systems were studied in a basic aqueous solution. Λ(R)-β-[Co(edda)(en)]+ isomerized to the Λ(S,S)-α-isomer with an optical purity (o.p.) of ca. 45%. In the reactions of three isomers of [Co(edda)(gly)], Λ(R)-β-fac(O) isomerized to Λ(R)-β-mer(O) (o.p.: ca. 100%) and Λ(S,S)-α-mer(O) (o.p.: ca. 33%), Λ(R)-β-mer(O) to Λ(R)-β-fac(O) (o.p.: ca. 65%) and Λ(S,S)-α-mer(O) (o.p.: ca. 40%), and Λ(S,S)-α-mer(O) to Λ(R)-β-fac(O) (o.p.: ca. 50%) and Λ(R)-β-mer(O) (o.p.: ca. 60%). These results were explained on the basis of a Co–O bond-rupture mechanism.
Effects of Chloro Substituent on Solvent Extraction of Copper(II) with o-, m-, and p-Chlorobenzoic Acids
Authors: Yamada Hiromichi , Horikawa Shiho , Fujii Yukio , Mizuta Masateru 
Published: July 2006

Abstract
Through the solvent extraction of copper(II) with the three isomeric chlorobenzoic acids in 1-octanol, it has been shown that the entrance of chloro substituent into the three positions in the benzene ring of benzoic acid results in an individuality in the extraction behavior for copper(II). The dimeric copper(II) chlorobenzoates CU2A4 and Cu2A4(HA)2 were responsible for the extraction with m-chlorobenzoic acid together with the monomer CuA2, while only the monomeric species CuA2 was extracted with o- and p-chlorobenzoic acids. The entrance of chloro group into the ortho position in benzoic acid was found to result in a lowering of both the partition constants of o-chlorobenzoic acid itself and its copper(II) compound. That into the para position has led to a significant decrease in the solubilities of the para isomer and its copper(II) compound in both aqueous and octanol phases.
Transformation of α-Santonin into 7-Hydroxyeudesmanes
Authors: Nagano Hajime , Sugihara Hiroko , Harada Noriko , Fukuchi Natsuko , Yamada Keiko , Izawa Hiroko , Shiota Michio 
Published: July 2006

Abstract
Autoxidation of (11S)-12-hydroxy-7α-eudesmane-3,6-dione in the presence of p-toluenesulfonic acid gave 6,12-epoxy-11β-eudesma-4,6-dien-3-one, which was oxidized with m-chloroperoxybenzoic acid to give (11R)-7α,12-dihydroxyeudesm-4-ene-3,6-dione. Transformation of some other 12-hydroxyeudesman-6-ones into 7,12-dihydroxyeudesman-6-ones was also examined.
Synthesis of 3′,4′,6′-Trideoxy-6′-Fluorokanamycin C, 3′,4′-Dideoxy-6′-C-(fluoromethyl)kanamycin B, and Their 1-N-[(S)-4-Amino-2-hydroxybutanoyl] Derivatives
Authors: Umemura Eijiro , Tsuchiya Tsutomu , Umezawa Sumio 
Published: July 2006

Abstract
3′,4′,6′-Trideoxy-6′-fluorokanamycin C (5) has been prepared by treatment of a protected kanamycin C derivative having the free 6-hydroxyl group with DAST, as the key step. Two 3′,4′-dideoxy-6′-C-(fluoromethyl)kanamycin B′s (17a and 17b) have been prepared from a 5′-C-aldehyde derivative of kanamycin C through a sequence of reactions involving nitromethane condensation and 6′,7′-(N-tosylepimino)-ring opening with KHF2, as the key steps. 1-N-[(S)-4-Amino-2-hydroxybutanoyl] derivatives of 5 and 17a were prepared by coupling of the [(S)-4-amino-2-hydroxybutanoyl] residue to the 1-amino group of 5 and 17a by utilizing the zinc acetate-ethyl trifluoroacetate method. Biological effects caused by the introduction of the fluorine atom in these products were discussed based on the chemical character of fluorine.
Conductometric and Spectrophotometric Investigations on Manganese(II) Decanoate in Organic Solvents
Authors: Mehrotra K N , Rawat M K 
Published: July 2006

Abstract
The specific conductance of manganese(II) decanoate in DMF and 1-butanol was measured with a view to determine the critical micelle concentration (CMC), degree of dissociation, and dissociation constant. It was found that the soap behaves as a simple electrolyte and is ionic in nature. The CMC was found to be independent of the dielectric constant of the solvent. The ionic character of manganese(II) decanoate was also confirmed by spectrophotometric measurements.
Alkylation of Phenol by 1-Dodecene and 1-Decanol. A Literature Correction
Authors: Campbell Curt B , Onopchenko Anatoli , Santilli Donald S 
Published: July 2006

Abstract
A recent literature report that 1-dodecene reacts with phenol in the presence of sulfated zirconium oxide (superacid), or 1-dodecanol with phenol in the precsence of H-Mordenite (zeolite), to afford mostly para-substituted alkylphenols has been shown to be incorrect. The product with zirconium is a mixture of ortho/para isomers (≈50–65/50–35), and not the exclusive para isomer as reported. The major product in the case of zeolite catalysis is the o-alkylphenol, with a high degree of end attachment, and not the predominantly claimed para isomers. The selectivity obtained with H-Mordenite during alkylation of phenol differs from the alkylation of alkylbenzenes and anisole, and is best explained on the basis of a surface catalysis phenomenon.
Polytopic Cation Receptors. III. Di- and Triloop Crown Hosts Having Aromatic Junctions. Synthesis, Cation Extraction, and Solid Complex Formation
Authors: Weber Edwin , Skobridis Konstantinos , Ouchi Mikio , Hakushi Tadao , Inoue Yoshihisa 
Published: July 2006

Abstract
A new type of crown compound (1–3) featuring an assembly of two or three individual macrorings with different ring size, rigidity, and donor atoms and having characteristic aromatic junctions is introduced. Syntheses are described and cation binding abilities of the compounds are evaluated by solvent extraction technique and isolation of solid complexes. Due to the number of macrorings and their property, 1–3 are shown to be suitable hosts for the common incorporation of several cations. However, cooperativity of adjacent macrorings in complex formation depending on the used cation is also observed. The constituent bis-crown ethers 4–6 and monocyclic crown ethers 7–10 were examined as comparative compounds for solving the complexation properties of the new hosts.
Thermal Decomposition of Copper(II) Polyamine Complexes
Authors: Ikoma Shuji , Nakasako Shigemori , Yokoi Hiroshi 
Published: July 2006

Abstract
The thermal decomposition of the complexes of copper(II) chloride and sulfate with polyamines has been investigated in detail by thermal analysis, X-ray powder diffraction and ESR spectroscopy. It has been revealed that the chloride complexes decompose to copper metal and carbonaceous product in nitrogen and to copper(I) chloride in air, and the sulfate complexes to copper(I) sulfide and carbonaceous product in nitrogen and to copper(II) oxide in air.
A Novel Method for the Conversion of Halide Anion to the Positive Halogen by Nitrobenzenesulfonyl Peroxide. Application to Oxyhalogenation of Olefin
Authors: Yoshida Masato , Mochizuki Hideki , Suzuki Takashi , Kamigata Nobumasa 
Published: July 2006

Abstract
Bromide and chloride anions could be readily oxidized into positive halogens by treating with p-nitrobenzenesulfonyl peroxide. The positive halogens, thus formed, reacted with olefins to give epihalonium ions, which were trapped by oxygen nucleophiles inter- or intramolecularly to afford oxyhalogenated compounds.
Stereoselective Synthesis of (−)-Trachelanthic Acid and (+)-Viridifloric Acid, Necic Acid Components of Pyrrolizidine Alkaloids from a Common Intermediate
Authors: Niwa Haruki , Ogawa Takeshi , Yamada Kiyoyuki 
Published: July 2006

Abstract
Diastereoselective reduction of a side-chain keto group in (2S,5R)-5-acetyl-2-(t-butyl)-5-isopropyl-1,3-dioxolan-4-one (5) with (i-Bu)2AlH in ether afforded (1′S,2S,5R)-2-(t-butyl)-5-(1′-hydroxyethyl)-5-isopropyl-1,3-dioxolan-4-one (6), while reduction of 5 with LiBH(s-Bu)3 in ether gave the (1′R)-isomer 7 predominantly. (−)-Trachelanthic acid (1) and (+)-viridifloric acid (2) were synthesized upon hydrolysis of 6 and 7, respectively.
The Reaction of Acetals with Silyl Enol Ethers Promoted by the Combination of Tin(II) Chloride and Organic Halide. Novel and Convenient Synthesis of α,β-Unsaturated Ketones
Authors: Oriyama Takeshi , Iwanami Katsuyuki , Miyauchi Yuka , Koga Gen 
Published: July 2006

Abstract
Acetals react with silyl enol ethers to give condensation products in good yield by the action of a reactive halide such as acetyl chloride or methoxymethyl chloride along with a catalytic amount of SnCl2. The procedure employing excessive amount of halide offers a novel and convenient method to synthesize conjugated enones.
Reaction of Methyl Propionate with Methylal over V–Si–P Ternary Oxide Catalysts
Authors: Ai Mamoru 
Published: July 2006

Abstract
The vapor-phase aldol condensation of methyl propionate with formaldehyde was performed using methylal as the source of formaldehyde. The main products were methyl methacrylate and methacrylic acid. The one-pass yield of methyl methacryalte plus methacrylic acid on methylal basis reached 53 mol% at a methyl propionate/methylal molar ratio of 2 over the V–Si–P oxide with an atomic ratio of 1:16: 3.2.
The Addition of 1,3-Diphenylisobenzofuran to Cyclooctatetraene and to Dimethyl Cyclooctatetraene-1,2-dicarboxylate. The Benzene Ring as a Dienophile in an Intramolecular Diels–Alder Reaction
Authors: Saito Katsuhiro , Omura Yoichi , Maekawa Etsuro , Gassman Paul G 
Published: July 2006

Abstract
The reaction of cyclooctatetraene with 1,3-diphenylisobenzofuran afforded two kinds of 1:1 [2π+4π]-cycloadducts, a cage-type 1:1 cycloadduct and two classes of 1:2 cycloadducts. The cage-type compound was formed from one of the [2π+4π]-cycloadducts via an unprecedented second [2π+4π]-cycloaddition reaction in which the double bond of the benzene moiety acted as a dienophile. A similar reaction with dimethyl cyclooctatetraene-1,2-dicarboxylate gave a 1:1 [2π+4π]-cycloadduct and a 1:2 cycloadduct. No cage-type compound was formed.
A New Enantioselective Approach to the Bicyclo[4.4.0]decane and Bicyclo[4.3.0]nonane Systems
Authors: Asaoka Morio , Nishimura Kuniko , Takei Hisashi 
Published: July 2006

Abstract
Highly diastereoselective routes to cis-fused bicyclo[4.4.0]decane-2,10-diones and bicyclo[4.3.0]nonane-2,9-diones from 5-trimethylsilyl-2-cyclohexen-1-one (1a) and its 3-methyl derivative were established by utilizing an annulation with ω-(alkoxycarbonyl)alkylzinc reagents. Bicyclo[4.4.0]decane-2,8-dione was obtained diastereoselectively by the double Michael reaction of 1a with dienol silyl ether. The diastereoselective Diels–Alder reaction of 1a with cyclopentadiene gave an endo adduct, which can be regarded as a new chiral cyclohexenone synthon, with a high optical purity.
17O NMR Study of Metal Carbonyl Cluster Compounds. IV. The Substituent Effect on the 17O NMR Chemical Shifts for a Series of Tri-Nuclear Metal Carbonyl Cluster Compounds
Authors: Onaka Satoru , Takagi Sigeru , Furuta Hiroyuki , Kato Yoshio , Mizuno Atushi 
Published: July 2006

Abstract
17O NMR spectra have been measured for series of cobalt carbonyl cluster derivatives, RCCo3(CO)9−x(PPh3)x, (RC2R′)Co3−x−yFexMoy(CO)9−yCpy, and R3−xSn[Co(CO)4]x+1. The small 17O-chemical shift differences due to the change of R and/or introduction of PPh3 have been interpreted in terms of the electron buffer action of the Co3 core for RCCo3(CO)9−x(PPh3)x. Good linear correlations between 17O-chemical shifts and CO stretching frequencies have been observed for these derivatives. Some effect of the magnetic anisotropy resulted from the ring current along the metal-triangle on 17O-chemical shifts has been suggested for metal-triangle clusters.
Syntheses and Catalytic Actions of Self-Micelle-Forming Hydrolase Models
Authors: Kawaguchi Kazuo , Ohkatsu Yasukazu , Kusano Tom 
Published: July 2006

Abstract
Hydrolase model catalysts, N-alkyl-Nα-[2-(d-polyhydroxypentyl)-3-acetyl-4-thiazolidinylcarbonyl]-l-histidinamide (acyclic-type catalyst) and N-(N-alkanoyl-l-nistidyl)-β-d-glucosamine (cyclic-type catalyst), which easily form micelles in water by themselves, have been designed and the stereostructural effects of sugar moieties examined on stereoselective hydrolyses of p-nitrophenyl N-benzyloxycarbonyl-l-(or d-)phenylalaninates. An acyclic-type catalyst is l-selective, while a cyclic-type catalyst is l-selective. The stereorecognition of acyclictype catalysts was found to be performed by a sugar moiety, rather than the histidyl type. Comparisons of the activities of three acyclic-type catalysts having different sugar moieties show that a mannose-derived catalyst is the most stereoselective. Judging from kinetic data, it is concluded that the configuration of OH on C-3 of the sugar moiety takes a significant part in the stereorecognition of a catalyst.
Photolysis of Triarylmethylphosphonic Acids and Their Esters
Authors: Shi Min , Okamoto Yoshiki , Takamuku Setsuo 
Published: July 2006

Abstract
Upon UV-irradiation in an alkaline alcohol solution, some triarylmethylphosphonic acids underwent C–P bond cleavage to give triarylmethanes and alkyl dihydrogenphosphates, while, in an acidic or a neutral alcohol solution, they afforded biaryls. Their dimethyl esters gave also biaryls and dimethyl [alkoxy(aryl)methyl]phosphonates, which were derived from the insertion of (dialkoxyphosphinyl)arylcarbenes into the OH bond of the alcohol. The carbene was generated by photo-α,α-elimination of two aryl groups of the phosphonate.
Studies on the Stereoselective Methylation of α-Sulfinyl Carbanions Generated from Three Isomeric Pyridylmethyl p-Tolyl Sulfoxides and Benzyl 2-Pyridyl Sulfoxide
Authors: Furukawa Naomichi , Hosono Eri , Fujihara Hisashi , Ogawa Satoshi 
Published: July 2006

Abstract
A high stereoselectivity in the methylation of 2-pyridylmethyl p-tolyl sulfoxide (2a) with lithium diisopropylamide and iodomethane was observed at low temperature. The chelation of Li+ by both the nitrogen atom in the pyridine ring and the sulfinyl oxygen atom in 2a promotes the stereoselectivity as compared with isomeric sulfoxides.
A Michael Addition and Alkylation Sequence Using Methyl 2-(Trimethylsilyl)propenoate. Stereoselective Synthesis of α-Silyl Esters
Authors: Tanaka Junji , Kanemasa Shuji , Ninomiya Yusuke , Tsuge Otohiko 
Published: July 2006

Abstract
Michael addition of organomagnesiums or -lithiums with methyl 2-(trimethylsilyl)propenoate leads to either 1:1 or 1:2 adduct anions, depending upon the reaction conditions and the reactivity of donor molecules. The adduct anions, both 1:1 and 1:2 types, are quenched with alkyl halides or water in a highly stereoselective manner to produce α-silylated esters. A rigid intramolecular chelation working in the adduct anions is partly responsible for the high selectivity.
Usefulness of the Peptide Segment Separation Method for Asparagine-Rich Protein Syntheses. Synthesis of Malaria Vaccine Analogs Having the Repeated Unit of l-Asparaginyl-l-Alanyl-l-Asparaginyl-l-Prolyl
Authors: Narita Mitsuaki , Takegahara Hitoshi , Ono Seiji , Sato Hisaya 
Published: July 2006

Abstract
In order to demonstrate the usefulness of “the peptide segment separation method” for syntheses of Asn-rich proteins, the central area of circumsporozoite protein of human malaria parasite plasmodium falciparum, Boc–(Asn–Ala–Asn–Pro)n–OBzl (n=2, 3, 4, 6, 9, 12, and 18), were prepared by the coupling reactions of H–(Asn–Ala–Asn–Pro)k–OBzl (k=1, 2, 3, 6, 9, and 12) with Boc–(Asn–Ala–Asn–Pro)m–OH (m=1, 3, or 6) using DCC and HOBt as coupling reagents. The peptide chains are separated into peptide segments by the tertiary peptide bonds of Asn–Pro moieties and they are assembled by the sequence of Asn–Ala–Asn separated by a Pro residue. Regardless of the increase in the peptide chain lengths of the amino and carboxyl components, the coupling reactions in DMF or NMP were achieved in high yields. The excellent solubility of the peptides in highly polar solvents was preserved in spite of the tendency for an Asn residue to have a high potential for aggregation through hydrogen bond formed by the side-chain amide group. The purification of the peptide series by recrystallization could be completely achieved and HPLC on a gel filtration column showed all the peptides to be monodisperse.
Synthetic Inorganic Ion-Exchange Materials. LIV. The Amphoteric Behavior of Hydrous Titanium Dioxide Ion Exchangers in Different Preparations
Authors: Sugita Mitsuru , Tsuji Masamichi , Abe Mitsuo 
Published: July 2006

Abstract
Hydrous titanium dioxides in amorphous form (Am-HTDO ) were prepared in a state demineralized as much as possible through different processes. The equiadsorption point (EAP) for anion and cation was determined at an ionic strength of 0.1 with the use of alkali metal chloride solution. The EAP values were strongly affected by the synthetic method, especially hydrolysis pH, and by the kind of probing cations, ranging from 2.7 to 4.5. Chloride ion uptake was not dependent on the kind of coexisting cations. The EAP value of Am-HTDO prepared at pH&gt;13 was appreciably lower than that of Am-HTDO prepared at pH 7–8. The “ion-free” Am-HTDO prepared by using the sol–gel method with Ti[OCH(CH3)3]4 showed approximately the same EAP value as that of Am-HTDO hydrolysed at a similar pH by NaOH solution.
Preparation of Iron and Cobalt Phthalocyanine-1,2:3,4:8,9:10,11:15,16:17,18:22,23:24,25-octakis(N-decyldicarboximide) and Their Catalytic Behavior for Electroreduction of Oxygen
Authors: Kobayashi Nagao , Sudo Keigo , Osa Tetsuo 
Published: July 2006

Abstract
The iron and cobalt phthalocyanines included in the title have been synthesized. Their absorption spectra are unusual compared to other metallophthalocyanines, showing intense hypochromism in the Q band region. The cobalt and iron derivatives show 4-electron reduction capability in the electroreduction of oxygen over the entire range of pH values and in neutral and alkaline pH, respectively, although the potentials are not necessarily positive enough.
Extractive Permeation of Zinc(II) and Cadmium(II) Chloride Complexes through Anion-Exchange Membrane
Authors: Hayashita Takashi , Kurosawa Takahiko , Ohya Shinji , Komatsu Tatsuo , Igawa Manabu 
Published: July 2006

Abstract
Extractive permeation is demonstrated in the permeation of Zn(II) and Cd(II) chloride complexes through an anion-exchange membrane. A selective permeation between Cd(II) and Zn(II) was observed. This selectivity well corresponded to the sorption selectivity with an anion-exchange resin. Under the large concentration gradient of chloride ions across a membrane, Cd(II) chloride complex was selectively enriched in the receiving solution. The concentration ratios between the source and the receiving solution after 40 h reached 5.8 for Cd(II) and 1.2 for Zn(II) when chloride ions of 0.5 mol dm−3 were added to the source solution.
Polarographic Determination of In(III) and Cd(II) in the Presence of Polyethylene Glycol in Hydrochloric Acid
Authors: Kurotu Takuzo 
Published: July 2006

Abstract
The simultaneous determination of In(III) and Cd(II) was investigated by d.c. polarography in the presence of polyethylene glycol (PEG) in 0.1 mol dm−3 hydrochloric acid. The PEG shifts the half-wave potential of Cd(II) from −0.67 to −0.82 V vs. SCE and reduces the wave height. A linear relationship between the wave height for Cd(II) and the concentration was obtained in the presence of various molecular weights of PEG. An increase in the molecular weight of PEG also causes a decrease in the wave height. On the other hand, a reduction wave of In(III) was not observed down to the reduction potential for hydrogen at a certain concentration of PEG. It is, therefore, possible to determine In(III) and Cd(II) separately, since Cd(II) can be determined by multiplying by a calibration factor. In(III) can also be determined by the difference between the merged-wave height for In(III) plus Cd(II) and the wave height for the determined Cd(II).
The Protective Effects of Cyclodextrins against the Oxidation of Methyl Orange by Singlet Oxygen
Authors: Miyajima Koichiro , Komatsu Hiroaki , Inoue Kazuhiro , Handa Tetsurou , Nakagaki Masayuki 
Published: July 2006

Abstract
The degradation of Methyl Orange (MO) by singlet oxygen was inhibited by the addition of α-, β-, and γ-cyclodextrins (CD’s) to an aqueous solution. The protective effect of the CD’s against the MO oxidation decreased in this order; α-&gt;γ-\gtrsimβ-CD. From the relation between the rate constant of MO oxidation and the free MO concentration, evaluated by using the formation constants of CD’s with MO, it was found that the MO included by α and γ-CD’s is not decomposed by singlet oxygen, whereas the MO included by β-CD is oxidized by singlet oxygen. The inner cavity of α- or γ-CD well fit for the inclusion of one or two MO molecules respectively, and the access of singlet oxygen to the azo group of the included MO molecule is sterically inhibited. The finding that β-CD has smaller enthalpy and larger entropy changes relevant to the formation of the MO–CD complex than those of α- and γ-CD’s suggested the less tight inclusion of one MO molecule in the cavity of β-CD. Such a loose inclusion of MO by β-CD resulted in the transient exposition of the azo group of the MO molecule to the bulk phase: the attack of the singlet oxygen on the azo group followed.
Bromocresol Green—A Hydrophobic Spectrophotometric Probe for Human Serum Albumin
Authors: Kishore S , Maruthamuthu Meenakshi 
Published: July 2006

Abstract
Bromocresol Green (BCG) has been developed as a new spectrophotometric probe for human serum albumin (HSA). The competing ligands naproxen (NP), 8-anilino-1-naphthalenesulfonate (ANS), and dansylsarcosine (DS) have been found to share common binding sites in HSA and their ability to displace BCG from the first competition site is in the order NP&gt;ANS&gt;DS.
The Syntheses, Crystal and Molecular Structures, and Their Thermal Properties of Tetramethylammonium [Octakis(isothiocyanato)lanthanoidates(III)]·benzene (1/2), [(CH3)4N]5[M(NCS)8]·2C6H6 (M=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy)
Authors: Matsumura Naomi , Takeuchi Toshio , Ouchi Akira 
Published: July 2006

Abstract
The titled series of isomorphous complexes, the first octakis(isothiocyanato) complexes of lanthanoids, were obtained. Their crystals are tetragonal, space group P4nc, Z=2. The cell dimensions of the praseodymium complex, for example, are a=15.871(7), c=11.543(6) Å, U=2908(3) Å3, and Dm=1.29(3), Dx=1.29 g cm−3, μ(MoKα)=11.60 cm−1, with a final R value of 0.069. The metal atom is octa-coordinated by eight isothiocyanate ions in an intermediate geometry between cube and square-antiprism. The benzene included in the praseodymium complex crystals was retained up to 174°C (DTA), and was not removed even after being heated for 12 h at 110°C. In cases of the other isomorphous members, the benzene was removed at lower temperatures, respectively. The isomorphous fluorobenzene adduct was obtained only for the lanthanum complex.