Ternary Chlorides of the Trivalent Early Lanthanides. Phase diagrams,crystal structures and thermodynamic properties

A comprehensive review on phase diagrams, crystal structures and thermodynamics of ternary chlorides formed in systems ACl/LnCl₃ (A=Cs, Rb, K, Na; Ln=La−Gd) is presented. The review summarizes the author’s own studies, published since 1985, and original papers of other scientists. With the larger alkali metal ions compounds such as A₃LnCl₆, A₂LnCl₅ and ALn₂Cl₇were obtained. With sodium additional compounds NaLnCl₄ and Na₃Ln₅Cl₁₈ were obtained. The crystal structures are discussed with the concept of ionic radii, which determine the coordination numbers of Ln³⁺ and A⁺ cations against Cl⁻ anions. The formation enthalpies of the compounds from ACl and LnCl₃ were determined by solution calorimetry. Gibbs’ free energies and entropies for these reactions were obtained by e.m.f. measurements vs. temperature. The stability of a ternary chloride in a systemACl−LnCl₃ is given by the ‘free enthalpy of synproportionation’, that is, the formation of a compound from its neighbour compounds in the system. This ΔG ⁰ _syn must be negative. A surprising result is, that the highest-melting compounds in the systems, A₃LnCl₆, are formed from ACl+A₂LnCl₅ by a loss in lattice energy. They exist as high-temperature compounds due to sufficiently high gain in entropy at temperatures whereTΔS>ΔH. This revised version was published online in August 2006 with corrections to the Cover Date.     

2-羰基丙酸(4-吡啶甲酰基)腙与碱土金属配合物的晶体结构及热 稳定性

报道了2-羰基丙酸(4-吡啶甲酰基)腙(H~2L)与碱土金属(Ca,Mg,Sr,Ba)四种配合物的合成,结构及热稳定性。同时,用X射线单晶衍射仪测定了Mg和Ba两种配合物的晶体结构,结构分析表明两种配合物均属单斜晶系,空间群均为P2~1/c。此外,还比较讨论了各配合物不同成键方式所对应的IR特征及热稳定性变化规律。     

离子色谱法测定中药女贞子浸煮液中的碱金属和碱土金属

用离子色谱法测定了中药女贞子水浸煮液中K+、Na+、Ca2+、Mg2+的含量,色谱柱为IonPAC CS 12A(4 mm×250 mm)阳离子交换柱,淋洗液为11.0 mmol/L的硫酸溶液,流速1.00mL/min,电导检测器检测。结果表明,4种离子的检出限分别为:Na+0.021 mg/L,K+0.020 mg/L、Mg2+0.015 mg/L,Ca2+0.100 mg/L,相对标准偏差在0.72%~3.92%之间,回收率为98.3%~103.1%。结论:该法操作简便、快速,准确,为测定其它中药中Na+、K+、Mg2+、Ca2+的含量提供了一种有效的方法。     

Spectroscopic study of the complexation of an aza-15-crown-5 containing chromofluoroionophore with Ba2+ and Ca2+ cations

The complexation of 1-[(4-benzothiazolyl)phenyl]-4,7,10,13-tetraoxa-1-aza-cyclopenta-decane with Ba²⁺ and Ca²⁺ cations was investigated spectrophotometrically and spectrofluorometrically. The stability constants of the complexes formed are: for Ba²⁺ logK _st=3.17±0.01 (absorption) and logK _st=2.95±0.03 (fluorescence); for Ca²⁺ logK _st=3.71±0.02 (absorption) and logK _st=3.58±0.05 (fluorescence). Protonation of the ligand leads to fluorescence quenching. AM1 and PPP quantum chemical calculations were used to predict molecular geometry, proton affinities and the spectra of the compounds studied.Dedicated to Prof. Dr. Karl-Heinz Drexhage on the occasion of his 60th birthday     

Mechanochemical syntheses,crystal structures,and photo-luminescent properties of a new hydrazone and its nickel and cadmium complexes

Abstract

A new hydrazone, ethyl Z-2-(pyridine-2yl-methylene)hydrazinecarboxylate (C₉H₁₁N₃O₂; Hpyec) and its metal complexes bis(ethyl Z-2-(pyridine-2yl-methylene)hydrazinecarboxylate)nickel(II) monohydrate, [Ni(pyec)₂]·H₂O (1) and bis(acetato)(ethyl Z-2-(pyridine-2yl-methylene)hydrazinecarboxylate)cadmium(II), [Cd(Hpyec)(CH₃COO)₂] (2), have been prepared by mechanochemical syntheses and characterized by elemental analysis, UV–vis, IR and NMR spectroscopies, TG-DTA, and solid state emission techniques. The X-ray single crystal structures of both complexes were determined. In 1, the Ni²⁺ ion is coordinated by two N,N,O-tridentate anionic ligands to generate a distorted cis-NiO₂N₄ octahedron. In 2, the cadmium ion is seven-coordinate by one neutral N,N,O-tridentate ligand and two chelating acetate ions to generate a very-distorted CdN₂O₅ pentagonal bipyramid with the Hpyec atoms occupying both axial and one equatorial site. Crystal data: 1, C₁₈H₂₂N₆NiO₅, M_r?=?461.12, monoclinic, P2₁/c, a?=?10.8759(3) Å, b?=?11.7055(4) Å, c?=?16.8424(5) Å, β?=?108.583(1)°, V?=?2032.38(11) ų, Z?=?4, R(F)?=?0.023, wR(F²)?=?0.065; 2, C₁₃H₁₇CdN₃O₆, M_r?=?423.69, monoclinic, Cc, a?=?13.0215(10) Å, b?=?15.8104(11) Å, c?=?7.99(6) Å, β?=?96.692(2)°, V?=?1621.7(2) ų, Z?=?4, R(F)?= 0.017, wR(F²)?=?0.038.     

Synthesis and Polymerization of N-Arylitaconimides: Free Radically and Anionic ally

N-Phenyl-, N-p-tolyl-, N-p-methoxyphenyl, N-o-ethyl phenyl-, and N-p-chlorophenylitaconimides were prepared from the corresponding taxonomic acids. These monomers were polymerized free radically to yield low molecular weight polymers. With the exception of N-p-chlorophenylitaconimide, all the above monomers polymerized anionic ally using n-butyl lithium as initiator. N-o-Ethylphenylitaconimide formed a cross-linked polymer when polymerized anionic ally. The inability of N-arylitaconimides to produce high molecular weight polymers was attributed to the allelic hydrogen's of the monomers.     

一种重金属离子吸附捕集剂的合成及性能研究

在较温和的温度条件下合成了N,N-双(二硫代羧基)二乙烯三胺乙基聚合物,并对NaOH的加入次序及加入量、二硫化碳加入次序、二乙烯三胺的用量、反应温度、反应时间等进行了研究。论文通过红外光谱、紫外光谱和熔点测定对聚合物进行表征。研究了聚合物吸附捕集部分重金属离子的性能,结果表明,合成的聚合物能稳定地吸附捕集某些重金属离子,对Ag 、Cu2 、Zn2 等离子有较高的吸附量;吸附效果在pH值为5左右时最好。     

The interaction of alkali metal cations with aromatic molecules in complexes of the type M[AlMe3X]·aromatic,M[Al2Me6X]·aromatic,and related

The crystal structures of 13 compounds of the form M[Al₂Me₆X]·aromatic and related have been examined in order to learn about the M⁺...aromatic approach. Four types of interactions have been discerned: (1) metal...aromatic, (2) metal...aromatic...metal, (3) aromatic...metal...aromatic, and (4) no metal...aromatic contact. It was found that the closest K⁺...C(aromatic) and Cs⁺...C(aromatic) separations are essentially equal after a correction for the difference in metal radii. The strength of the K⁺...aromatic attraction was found to be sufficient to move the K⁺ ion 0.3 Å out of the plane of the crown ether in two complexes of dibenzo-18-crown-6.     

Synthesis and selectivity of sym-hydroxydibenzo-14crown-4 ionophores for protons,alkali metal cations,and alkaline earth cations in polymeric membranes

Six derivatives of sym-hydroxydibenzo-14-crown-4 have been prepared and incorporated into solvent-polymeric membranes. Responses of the membranes to protons, alkali metal cations, and alkaline earth cations have been determined. The preferred uptake of protons is attributed to proton complexation by stable crown ether alcohol and diol monohydrate species.     

Reactions of azulenes with 1,2-diaryl-1,2-ethanediols in methanol in the presence of hydrochloric acid: comparative studies on products, crystal structures, and spectroscopic and electrochemical properties

Although reaction of guaiazulene (1a) with 1,2-diphenyl-1,2-ethanediol (2a) in methanol in the presence of hydrochloric acid at 60 °C for 3 h under aerobic conditions gives no product, reaction of 1a with 1,2-bis(4-methoxyphenyl)-1,2-ethanediol (2b) under the same reaction conditions as 2a gives a new ethylene derivative, 2-(3-guaiazulenyl)-1,1-bis(4-methoxyphenyl)ethylene (3), in 97% yield. Similarly, reaction of methyl azulene-1-carboxylate (1b) with 2b under the same reaction conditions as 1a gives no product; however, reactions of 1-chloroazulene (1c) and the parent azulene (1d) with 2b under the same reaction conditions as 1a give 2-[3-(1-chloroazulenyl)]-1,1-bis(4-methoxyphenyl)ethylene (4) (81% yield) and 2-azulenyl-1,1-bis(4-methoxyphenyl)ethylene (5) (15% yield), respectively. Along with the above reactions, reactions of 1a with 1,2-bis(4-hydroxyphenyl)-1,2-ethanediol (2c) and 1-[4-(dimethylamino)phenyl]-2-phenyl-1,2-ethanediol (2d) under the same reaction conditions as 2b give 2-(3-guaiazulenyl)-1,1-bis(4-hydroxyphenyl)ethylene (6) (73% yield) and (Z)-2-[4-(dimethylamino)phenyl]-1-(3-guaiazulenyl)-1-phenylethylene (7) (17% yield), respectively. Comparative studies of the above reaction products and their yields, crystal structures, spectroscopic and electrochemical properties are reported and, further, a plausible reaction pathway for the formation of the products 3-7 is described.     

Organotin complexes of pyruvic acid thiosemicarbazone: Synthesis,crystal structures and antiproliferative activity of neutral and cationic diorganotin complexes

The synthesis and spectral characterization of novel neutral and cationic organotin complexes with pyruvic acid thiosemicarbazone, H₂pt (1), [SnPh₂(pt)] (2), [SnMe₂(Hpt)(H₂O)]Cl (3) and [SnPh₂(Hpt)(H₂O)]Cl (4) are reported. The crystal structure of the complexes [SnPh₂(pt)] (2) and [SnMe₂(Hpt)(H₂O)]Cl (3) have been solved by single-crystal X-ray diffraction. The crystal structure of complex 2 showed that the ligand is doubly deprotonated at the oxygen and amide nitrogen atoms and is coordinated to the SnPh₂ fragment via two five-membered chelate rings. The monomers of 2 are linked through intermolecular hydrogen bonds of C−H–O type and through π−π intermolecular interactions. The crystal structure of [SnMe₂(Hpt)(H₂O)]Cl (3) showed that the ligand is mono-deprotonated at the oxygen atom and is coordinated to the SnMe₂ fragment via two five-membered chelate rings. The counter ion chloride is participated in intermolecular hydrogen bonds. An extended network of intermolecular hydrogen bonds leads to aggregation and a supramolecular assembly. The IR and NMR spectroscopic data of the complexes are reported. The in vitro cytotoxic activity has been evaluated against the cells of three human cancer cell lines: MCF-7 (human breast cancer cell line), T-24 (bladder cancer cell line), A-549(non-small cell lung carcinoma) and a mouse L-929 (a fibroblast-like cell line cloned from strain L). The most active of all was found the diorganotin complex 2. The cytotoxic activity shown by these compounds against all these cancer cell lines indicates that coupling of 1 with R₂Sn(IV) metal center result in metallic complexes with important biological properties and remarkable cytotoxic activity, since they are display IC₅₀ values in a μM range the same or better to that of the antitumor drug cisplatin. Compound 2 is considered as agent with potential antitumor activity, and can therefore be candidate for further stages of screening in vitro and/or in vivo.     

Synthesis and application of a molecularly imprinted polymer in the solid-phase extraction of ketoprofen from wastewater

Ketoprofen is a nonsteroidal anti-inflammatory drug widely consumed by humans as it possesses analgesic activities. A selective molecularly imprinted polymer (MIP) for ketoprofen was synthesized and applied as a solid-phase extraction sorbent. MIP was synthesized using 2-vinylpyridine, ethylene glycol dimethacrylate, 1,1′-azobis(cyclohexanecarbonitrile), toluene/acetonitrile (9:1, v/v), and ketoprofen as a functional monomer, cross-linker, initiator, porogenic mixture, and template, respectively. The polymerization was performed at 60 °C for 16 h, and thereafter the temperature was increased to 80 °C for 24 h to achieve a solid monolith polymer. Nonimprinted polymer was synthesized in a similar manner with the omission of ketoprofen. Characterization with thermogravimetric analysis and X-ray diffraction showed that the synthesized polymers were thermally stable and amorphous. Solid-phase extraction cartridges packed with MIP were used with high-performance liquid chromatography for quantitative analysis of ketoprofen in wastewater. The analytical method gave detection limits of 0.23, 0.17, and 0.09 μg/L in wastewater influent, effluent, and deionized water, respectively. The recovery for the wastewater influent and effluent spiked with 5 μg/L of ketoprofen was 68%, whereas 114% was obtained for deionized water. The concentrations of ketoprofen in the influent and effluent samples were in the ranges of 22.5–34.0 and 1.14–5.33 μg/L, respectively. Overall, the analytical method for the analysis of ketoprofen in wastewater was rapid, affordable, accurate, precise, sensitive, and selective.     

X‐ray structures,spectroscopic, electrochemical,thermal, antibacterial,and DFT studies of two nickel(II) and cobalt(III) complexes constructed from a new quinazoline‐type ligand

Two two‐dimensional supramolecular Nickel(II) and Cobalt(III) complexes, [Ni( L ² )₂]·2CH₃OH ( 1 ) and [2Co( L ² )₂] ( 2 ) ( HL ²  = 1‐(2‐{[(E)‐3‐bromo‐5‐chloro‐2‐hydroxybenzylidene]amino}phenyl)ethanone oxime), were synthesized via complexation of salts acetate with HL ¹ (2‐(3‐bromo‐5‐chloro‐2‐hydroxyphenyl)‐4‐methyl‐1,2‐dihydroquinazoline 3‐oxide, H is the deprotonatable hydrogen). During the reaction, the C–N bond in HL ¹ is converted into the C=N–OH group in HL ² . The spectroscopic data of both complexes were compared with the ligand HL ¹ . HL ¹ and both complexes were determined by single‐crystal X‐ray crystallography. The differently geometric features of the obtained complexes 1 and 2 are observed. In the crystal structure, 1 and 2 form an infinite 1‐D chain‐like and 2‐D supramolecular frameworks. EPR spectroscopy of 2 was investigated. Moreover, electrochemical properties and antimicrobial activities of both complexes were also studied. In addition, the calculated HOMO and LUMO energies show the character of HL ¹ , complexes 1 and 2 . The electronic transitions and spectral features of HL ¹ and both complexes were discussed by TD‐DFT calculations.     

Coordination of a mesogenic Schiff-base with Mn, Co, Ni, Cu and Zn: Synthesis, spectral studies and crystal structures

A novel mesogenic (nematic) Schiff-base, N,N′-di-4-(4′-pentyloxybenzoate)salicylidene diaminoethane, H₂dpbsde (abbreviated as H₂L⁵) was synthesized and its structure studied. The Schiff-base crystallizes in the non-centrosymmetric space group Pna2₁ with Z = 4, and the mesogenic isomorphous nickel and copper complexes, [NiL⁵]₂ and [CuL⁵], in the centrosymmetric space group P2₁/c with Z = 4. The (L⁵)²⁻ species coordinates to the metal ions through two phenolate oxygens and two azomethine nitrogens. Both the [NiL⁵]₂ and [CuL⁵] complexes involve cis-MN₂O₂ planes; the former complex has a low-spin distorted square-pyramidal geometry with a Ni–Ni bonding of 3.337 Å and the latter, a square-planar geometry.     

Isomerism in metal complexes of 1,3,5-diazaphosphorinanes. Synthesis,crystal and molecular structure of conformers ofcis-bis(1,3,5-triphenyl-1,3,5-triazaphosphorinane)dichloroplatinum(II)

The crystal and molecular structures were determined for two individual conformers ofcis-bis(1,3,5-triphenyl-1,3,5-diazaphosphorinane)dichloroplatinum(II) differing in the rotation of the heterocyclic ligand planes around the P-Pt bond and in the orientation of the substituents at the phosphorus atoms in the ligands.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1650–1655, September, 1993.     

Synthesis, characterization and crystal structures of boron-containing intermediates in the reductive amination of ferrocenecarboxaldehyde to a bis(ferrocenylmethyl) amine

Reaction of ferrocenecarboxaldehyde with aqueous methylamine leads to [(methylimino)methyl]ferrocene, which is reduced to N-(ferrocenylmethyl)-N-methylamine by NaBH₄. This amine reacts with ferrocenecarboxaldehyde and NaCNBH₃ to give the tertiary ammonium salt, di(N-(ferrocenylmethyl))-N-methylammonium cyanoborohydride. Hydrolysis of the NaCNBH₃ reaction mixture produces the free amine, di(N-(ferrocenylmethyl))-N-methylamine. Thermolysis of di(N-(ferrocenylmethyl))-N-methylammonium cyanoborohydride in refluxing tetrahydrofuran converts it to the cyanoborane adduct, di(N-ferrocenylmethyl)-N-methylamine-cyanoborane, with elimination of H₂. The new compounds are fully characterized by using spectroscopic and physical methods, including X-ray crystal structure determinations of di(N-(ferrocenylmethyl))-N-methylammonium cyanoborohydride, di(N-(ferrocenylmethyl))-N-methylamine, and di(N-(ferrocenylmethyl))-N-methylamine-cyanoborane.     

Syntheses, crystal structures of a series of copper(II) complexes and their catalytic activities in the green oxidative coupling of 2,6-dimethylphenol

Three mixed-ligand Cu^II complexes bearing iminodiacetato (ida) and N-heterocyclic ligands, namely, [Cu₂(ida)₂(bbbm)(H₂O)₂] · H₂O (1), [Cu₂(ida)₂(btx)(H₂O)₂] · 2H₂O (2) and [Cu₂(ida)₂(pbbm)(H₂O)₂] · H₂O · 3CH₃OH (3) (bbbm = 1,1^′-(1,4-butanediyl)bis-1H-benzimidazole, btx = 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene, pbbm = 1,1^′-(1,3-propanediyl)bis-1H-benzimidazole), in addition to three fcz-based Cu^II complexes, namely, {[Cu(fcz)₂(H₂O)₂] · 2NO₃}_n (4), {[Cu(fcz)₂(H₂O)] · SO₄ · DMF · 2CH₃OH · 2H₂O}_n (5) and {[Cu(fcz)₂Cl₂] · 2CH₃OH}_n (6) (fcz = 1-(2,4-difluorophenyl)-1,1-bis[(1H-1,2,4-triazol-l-yl) methyl]ethanol) have been prepared according to appropriate synthetic strategies with the aim of exploiting new and potent catalysts. Single crystal X-ray diffraction shows that 1 and 2 possess similar binuclear structures, 3 features a 2D pleated network, and 4 exhibits a 1D polymeric double-chain structure. Complexes 1-6 are tested as catalysts in the green catalysis process of the oxidative coupling of 2,6-dimethylphenol (DMP). Under the optimized reaction conditions, these complexes are catalytically active by showing high conversion of DMP and high selectivity of PPE. The preliminary study of the catalytic-structural correlations suggests that the coordination environment of the copper center have important influences on their catalytic activities.     

Synthesis and crystal structures of RE7Zn21+xSi2–x [RE = Ce,Pr, and Nd; 0.09 (1) < x < 0.95 (1)]

The focus of this paper is on the synthesis and crystal structures of three Zn‐rich compounds with the general formula RE₇Zn_21+xSi_2−x, where RE = Ce [x = 0.95 (1); heptacerium docosazinc silicon], Pr [x = 0.09 (1); heptapraseodymium henicosazinc disilicon], and Nd [x = 0.53 (1); heptaneodymium docosazinc silicon]. The compounds were obtained by high‐temperature reactions, using the respective elements as starting materials. The structures were determined by single‐crystal X‐ray diffraction. The title compounds crystalize in the orthorhombic space group Pbam (No. 55, Pearson symbol oP60) and are isostructural with about a dozen RE₇Zn_21+xTt_2−x (RE = La–Nd; Tt = Ge, Sn, and Pb) compounds previously reported by our group. The results from the present refinements confirm the previously published data on RE₇Zn_21+xSi_2−x (RE = La and Ce; x≃ 1.45) [Malik et al. (2013). Intermetallics, 36 , 118–126]. Additionally, magnetic susceptibility measurements on the corresponding bulk samples show Curie–Weiss paramagnetic behavior from 5 to 300 K, consistent with RE³⁺ ground states and local‐moment magnetism due to the core 4f electrons.     

Synthesis,crystal structures and fluorescence properties of two new di- and polynuclear Cd(II) complexes with N2O donor set of a tridentate Schiff base ligand

Two new Cd(II) complexes, having one binuclear structure [Cd₂(L)₂(Cl)₂] (1) and another azido bridged one-dimensional zig-zag polynuclear network [Cd₃(μ_1,1-N₃)₄(L)₂{H₂N(CH₂)₂N(C₂H₅)₂} · H₂O]_n (2) have been synthesized from a tridentate N₂O donor Schiff base ligand LH, [LH = (OCH₃)(OH)C₆H₃CHN(CH₂)₂N(C₂H₅)₂], which is the condensation product of 2-hydroxy-4-methoxybenzaldehyde and 2-diethylaminoethylamine. Both the complexes 1 and 2 have been characterized by elemental analyses, IR & ¹H NMR spectroscopy, TGA and fluorescence studies. Finally their structures have been established by single crystal X-ray diffraction method. Structural study reveals that in the complex 1, two Cd(II) centers are held together by two μ₂-phenolato oxygen atoms and the terminal chlorine atom occupies the apical site of the square pyramidal environment of each metal center. In case of complex 2, the trinuclear asymmetric unit contains octahedral Cd(II) centers which are further held together by doubly end-on azido bridging to form a zig-zag polynuclear structure. It also displays intraligand ¹(π–π^∗) fluorescence and can potentially serve as photoactive material.     

Simultaneous analysis of gemfibrozil,morphine, and its two active metabolites in different mouse brain structures using solid‐phase extraction with ultra‐high performance liquid chromatography and tandem mass spectrometry with a deuterated internal standard

A rapid and sensitive bioassay was established and validated to simultaneously determine gemfibrozil, morphine, morphine‐3β‐glucuronide, and morphine‐6β‐glucuronide in mouse cerebrum, epencephalon, and hippocampus based on ultra‐high performance liquid chromatography and tandem mass spectrometry. The deuterated internal standard, M6G‐d3, was mixed with the prepared samples at 10 ng/mL as the final concentration. The samples were transferred into the C₁₈ solid‐phase extraction columns with gradient elution for solid‐phase extraction. The mobile phase consisted of methanol and 0.05% formic acid (pH 3.2). Multiple reaction monitoring has been applied to analyze gemfibrozil (m/z 249.0 → 121.0) in anion mode, and M6G‐d3 (m/z 465.1 → 289.1), morphine (m/z 286.0 → 200.9), and M3G and M6G (m/z 462.1 → 286.1) in the positive ion mode. The method has a linear calibration range from 0.05 to 10 ng for gemfibrozil, morphine, and M3G and M6G with correlation coefficients >0.993. The lower limit of quantitation for all four analytes was 0.05 ng/mL, relative standard deviation of intra‐ and interday precision was less than 10.5%, and the relative error of accuracy was from ?8.2 to 8.3% at low, medium, and high concentrations for all the analytes. In conclusion, gemfibrozil can influence the morphine antinociception after coronary heart disease induced chronic angina by the change in one of morphine metabolites', M3G, distribution in mouse brain.