Formation and Structure of [Al_(13)(μ_3-OH)_6(μ_2-OH)_6(μ_2-OH)_(12)(H_2O)_(24)]Cl_(15)·13H_2O

1 INTRODUCTION At present, the polyaluminium compounds are mainly studied by single-crystal X-ray diffraction method to obtain the components, structures and exis- tence forms of aluminium in hydrolysis system, and then hydrolysis courses and mechanisms of each hydrolytic polyaluminium cation could be further dis- closed[1～5]. Generally, the single crystals suitable for X-ray diffraction are obtained from the crystallization of polyaluminium cations into sulfates or selenates. Following …     

Crystal structure of [Pd3(μ-OH)(μ-CH3COO)5]

The crystals of the [Pd₃(μ-OH)(μ-CH₃COO)₅] complex are obtained and characterized using powder and single crystal X-ray diffraction and IR spectroscopy. The crystal structure (a = 15.6942(6) Å, b = 11.7190(3) Å, c = 9.7871(3) Å, V = 1800.05(10) ų, space group Pna2₁, Z = 4) is formed from neutral trinuclear cyclic molecules of [Pd₃(μ-OH)(μ-CH₃COO)₅], in which the OH^? group, together with five CH₃COO^? anions, is a bridge ligand.     

Synthesis and Structure of a Novel Mg6 Cluster Molecule Mg6(μ3-OH)2(μ3-Br)2(μ-Br)8(THF)8

A novel Mg₆ cluster molecule with the formula of Mg₆( ₃-OH)₂( ₃-Br)₂(-Br)₈(THF)₈ (1) has been isolated in 38% yield from a reaction of the Grignard reagent, 2-naphthyl-Mg-Br with BBr₃ in THF. The structure of 1, determined by a single-crystal X-ray diffraction analysis, contains two Mg₃ triangles linked together by two bridging bromide ligands. Within each Mg₃ triangle, one hydroxide and one bromide ligand function as triply bridging ligands capping both sides of the Mg₃ triangle. The coordination geometry around each Mg(II) ion is approximately octahedral. NMR studies revealed that compound 1 is highly fluxional in solution.     

Fmoc-His(Mtt)-OH的合成

以二氯二甲基硅烷为双保护试剂,在碱性条件下组氨酸(His)的咪唑环和α-氨基位分别引入4-甲基-三苯甲基(Mtt)和9-笏甲氧羰基(Fmoc)保护基,合成了Fmoc-His(Mtt)-OH,其结构经1H NMR和MS确证。     

Reactions of triosmium clusters Os3(CO)11(MeCN) and (μ-H)Os3(CO)10(μ-OH) withL-α-serine ethyl ester and ethanolamine

A series of novel chiral complexes with ,¹and ,² coordination of organic ligands were prepared by reactions of Os₃(CO)₁₁(MeCN) and (-H)Os₃(CO)₁₀(-OH) withL--serine ethyl ester and ethanolamine. The diastereomeric cluster complexes with serine ligands were separated by crystallization or chromatography. The structures of the compounds obtained were confirmed by¹H NMR and IR spectroscopy, mass-spectrometry, elemental analysis, and X-ray diffraction analysis.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 525–530, March, 1994.     

Two heptacopper(II) disk complexes with a [Cu(7)(μ(3)-OH)(4)(μ-OR)(2)](8+) core

The reaction of CuX(2) (X(-) ≠ F(-)) salts with 1 equiv of 3-pyridyl-5-tert-butylpyrazole (HL) in basic methanol yields blue solids, from which disk complexes of the type [Cu(7)(μ(3)-OH)(4)(μ-OR)(2)(μ-L)(6)](2+) and/or the cubane [Cu(4)(μ(3)-OH)(4)(HL)(4)](4+) can be isolated by recrystallization under the appropriate conditions. Two of the disk complexes have been prepared in crystalline form: [Cu(7)(μ(3)-OH)(4)(μ-OCH(2)CF(3))(2)(μ-L)(6)][BF(4)](2) (2) and [Cu(7)(μ(3)-OH)(4)(μ-OCH(3))(2)(μ-L)(6)]Cl(2)·xCH(2)Cl(2) (3·xCH(2)Cl(2)). The molecular structures of both compounds as solvated crystals can be described as [Cu?Cu(6)(μ-OH)(4)(μ-OR)(2)(μ-L)(6)](2+) (R = CH(2)CF(3) or CH(3)) adducts. The [Cu(6)(μ-OH)(4)(μ-OR)(2)(μ-L)(6)] ring is constructed of six square-pyramidal Cu ions, linked by 1,2-pyrazolido bridges from the L(-) ligands and by basal, apical-bridging hydroxy or alkoxy groups, while the central Cu ion is bound to the four metallamacrocyclic hydroxy donors in a near-regular square-planar geometry. The L(-) ligands project above and below the metal ion core, forming two bowl-shaped cavities that are fully (R = CH(2)CF(3)) or partially (R = CH(3)) occupied by the alkoxy R substituents. Variable-temperature magnetic susceptibility measurements on 2 demonstrated antiferromagnetic interactions between the Cu ions, yielding a spin-frustrated S = (1)/(2) magnetic ground state that is fully populated below around 15 K. Electrospray ionization mass spectrometry, UV/vis/near-IR, and electron paramagnetic resonance measurements imply that the heptacopper(II) disk motif is robust in organic solvents.     

Preparation of organozirconium aromatic compounds in mixed aqueous-organic solvents: X-ray structures of [Cp2ZrCl(μ2-O′,O′′C-C6H5)], [(CpZr)3(μ2-O′,O′′C-C6H3Cl2)3(μ3-OH)(μ2-OH)3](Cl2C6H3COO)2, and [(CpZr)3(μ2-O′,O′′C-C6H4Cl)3(μ3-OH)(μ2-OH)3]Cl2·CH2Cl2

A new and facile method is presented for the synthesis of zirconocene carboxylate compounds, in which zirconocene dichloride (Cp₂ZrCl₂) is dissolved in 1 M aqueous HCl solution and the requisite ligand is dissolved in an organic solvent. Five such compounds [Cp₂ZrCl(μ₂-O′,O′′C-C₆H₅)] (1), [Cp₂ZrCl(μ₂-O′,O′′C-C₆H₃Cl₂)] (2), [Cp₂Zr(μ₂-O′,O′′C-C₆H₃(OH)Cl)₂] (3), [Cp₂Zr(μ₂-O′,O′′C-C₆H₃(OH)(NO₂))₂] (4), and [Cp₂Zr(μ₂-O′,O′′C-C₆H(OH)Cl₃)₂] (5) have been obtained by this method. The effect of pH on the stability of Cp₂ZrCl₂ in 1 M HCl solution has been investigated by UV/vis spectrophotometry and ¹H NMR spectrometry. The results showed that the aqueous Cp₂ZrCl₂ solutions became less stable with increasing pH, liberating cyclopentadiene. Accordingly, at higher pH (～7), two trinuclear zirconium monocyclopentadienyl compounds, [(CpZr)₃(μ₂-O′,O′′C-C₆H₃Cl₂)₃(μ₃-OH)(μ₂-OH)₃](Cl₂C₆H₃COO)₂ (6) and [(CpZr)₃(μ₂-O′,O′′C-C₆H₄Cl)₃(μ₃-OH)(μ₂-OH)₃]Cl₂·CH₂Cl₂ (7), were obtained. All compounds 1–7 have been characterized by FT-IR, ¹H NMR spectra and elemental analysis. In all of the compounds, the aromatic acid acts as a bidentate ligand in coordinating to the zirconium; both chelating and bridging modes are observed. X-ray crystallographic studies on 1, 6, and 7 have revealed that the geometries at zirconium are distorted octahedral in 6 and 7, and distorted trigonal-bipyramidal in 1.     

Fmoc-DOPA(acetonide)-OH的简单高效合成

受贻贝粘附蛋白启发而产生的3,4-二羟基苯丙氨酸(DOPA)衍生物引起了人们对生物材料和医疗器械的功能化涂层产生广泛兴趣.芴甲氧羰酰基-3,4-二羟基缩丙酮-L-苯丙氨酸[Fmoc-DOPA(acetonide)-OH]是贻贝粘附蛋白和多肽的固相合成关键原料.然而,现有的Fmoc-DOPA(acetonide)-OH的合成方法步骤繁琐、成本高,使其实际应用受到极大阻碍.本工作报道的两步法策略制备Fmoc-DOPA(acetonide)-OH,是一种简单且经济高效的合成方法,具有广阔的应用前景.     

A Novel Pentadecanuclear Neodymium Cluster: Synthesis and Structure of [Nd_(15)(μ_4-tyr)_(10)(μ_3-OH)_(20)(μ_2-OH)_4(OH)_(10)(μ_2-H_2O)-(H_2O)_(10)][Na(ClO_4)_2]·61H_2O

Inthepastfewyears,nearly50kindsofrareearthcomplexeswithaminoacidswerestructurallycharacterizedl.AllofthesecomplexesweresynthesizedunderpHI--4.Astheaminoacidligandsinthesecomplexesareintheirinnersaltformsandtheandnogroupsareprotonned,theycoordinatewithrareearthionsonlybyusingtheircarboxylgroups.Wehavenoticedthatthedeprotonizationoftheprotonnedaminogroupsisnecessarybeforethenitrogenatomsoftheaminogroupscancoordinatewiththemetalions.BycarefullyadjustingthePHvalueofasolutiontoabout5,wecrystalliz…     

Synthesis and Molecular Structure of Tris(pentamethylphenyl)aluminum, (C6Me5)3Al, and the Magnesium Cluster [Mg6(μ3-OH)2(μ3-Br)2(μ2-Br)8(OEt2)8]

The synthesis and molecular structures of tris(pentamethylphenyl)aluminum, (C₆Me₅)₃Al, (I), and the magnesium cluster [Mg₆( ₃-OH)₂( ₃-Br)₂( ₂-Br)₈(OEt₂)₈] (II), are reported. Both compounds were isolated from the same system. The aluminum atom in (I) resides in an almost idealized trigonal planar environment. The dihedral angles of the pentamethylphenyl rings relative to the AlC₃plane in (I) are 67.2, 62.4, and 61.2°. The neutral magnesium cluster, (II), is interesting in that contains six magnesium atoms each of which resides in octahedral environments.     

Synthesis,characterization, and catalytic activity of a water soluble copper(II) and nickel(II) heterobimetallic complex [CuNi(μ-OH)(μ-OH2)(μ-OAc)(bpy)2](ClO4)2 in aqueous medium in the absence of a base and co-catalyst

A copper(II)–nickel(II)-based catalyst system has been synthesized and characterized by elemental analysis, molar conductance, mass spectra, magnetic moment, EPR, UV-Vis, IR spectroscopy, and cyclic voltammetry. The structure of the complex was established by X-ray crystallography. The complex is an efficient catalyst, which oxidizes primary and secondary alcohols to the corresponding aldehydes and ketones at 70 °C employing 15% H₂O₂ as the oxidant in the absence of a base and co-catalyst.     

New triosmium–iridium clusters: Synthesis and molecular structure of [Os3Ir2(Cp1)2(μ-OH)(μ-CO)2(CO)8Cl] (1), [Os3IrCp1(μ-OH)(CO)10Cl] (2), [Os3IrCp1(μ-H)(μ-Cl)(η3,μ3-C5H2N(NH2)Br)(CO)9] (3) and [Os3IrCp1(μ-Cl)2(η2,μ3-C5H3N(NH)Br)(CO)7] (4)

The trinuclear osmium carbonyl cluster, [Os₃(CO)₁₀(MeCN)₂], is allowed to react with 1 equiv. of [IrCp¹Cl₂]₂ (Cp¹ = pentamethylcyclopentadiene) in refluxing dichloromethane to give two new osmium–iridium mixed-metal clusters, [Os₃Ir₂(Cp¹)₂(μ-OH)(μ-CO)₂(CO)₈Cl] (1) and [Os₃IrCp¹(μ-OH)(CO)₁₀Cl] (2), in moderate yields. In the presence of a pyridyl ligand, [C₅H₃N(NH₂)Br], however, the products isolated are different. Two osmium–iridium clusters with different coordination modes of the pyridyl ligand are afforded, [Os₃IrCp¹(μ-H)(μ-Cl)(η³,μ₃-C₅H₂N(NH₂)Br)(CO)₉] (3) and [Os₃IrCp¹(μ-Cl)₂ (η²,μ₃-C₅H₃N(NH)Br)(CO)₇] (4). All of the new compounds are characterized by conventional spectroscopic methods, and their structures are determined by single-crystal X-ray diffraction analysis.     

Formation of the unusual cluster Cu4(μ4-OH)(μ-(CF3)2pz)4(μ-OOCPh)2(μ-OH)2(OH2)(Et3NH)[O(CH2Ph)2]2 in the thermolysis of a copper μ-aqua complex with bridging pyrazolate and acetate ligands in dibenzyl ether in the presence of atmospheric oxygen

A room-temperature reaction of cupric acetate dihydrate with 3,5-bis(trifluoromethyl)pyrazole ((CF₃)₂pzH) in chloroform in the presence of triethylamine gave a complex of the formula [Cu₂(??-(CF₃)₂pz)₂(??-OH₂)(OC(Me)OHNEt₃)(OH₂)(HCCl₃)(OOCMe)(??-OOCMe)]₂ (2). Heating of this complex at 180°C in dibenzyl ether (DBE) in air yielded the tetranuclear pyrazolate-benzoate cluster Cu₄(??₄-OH)(??-(CF₃)₂pz)₄(??-OOCPh)₂(??-OH)₂(OH₂)(Et₃NH)[O(CH₂Ph)₂]₂. It was suggested that such complexes can be intermediates in the liquid-phase oxidation of DBE with atmospheric oxygen in the presence of copper complexes containing pyrazolate bridges.     

Reactions of the triosmium cluster Os3(μ-H)(μ-OH)(CO)10 with naphthols

Reaction of the cluster Os₃(μ-H)(μ-OH)(CO)₁₀ (1) with 1-naphthol afforded the isomeric clusters 2a and 3a with the formulae Os₃(μ-H)₂(μ₃-1-OC₁₀H₆)(CO)₉. A similar reaction with 2-naphthol, however, gave Os₃(μ-H)(μ-2-OC₁₀H₇)(CO)₁₀, 4b, and the analogue of 2a. These clusters have been structurally characterised to confirm the mode of anchoring of the naphthols.     

Synthesis and crystal structure of platinum(II) acetamidates [Pt(2,2′-bipy)(NHCOCH3)2] and [enPt(μ-NHCOCH3)(μ-OH)Pten](NO3)2

The diamines PtbipyCl₂, and PtenCl₂ and their aqua and hydroxy derivatives react with acetonitrile to give the Pt(II) acetamidates [Pt(2,2′-bipy)(NHCOCH₃)₂] · 4.125 H₂O (I) and [enPt(μ-NHCOCH₃(μ-OH)Pten](NO₃)₂ · H₂O (II), which are characterized by X-ray diffraction. The crystals of I are triclinic, a = 7.137(10) Å, b = 12.655(3) Å, c = 21.914(6) Å, α = 81.82(2)°, β = 82.12(2)°, γ = 77.72(2)°, V = 1908.6(7) ų, space group P $\overline 1 $ , Z = 4, R = 0.033 for 3700 reflections. Complex I is a mononuclear acetamidate with terminal (NHCOCH₃)^? ligands. The crystals of II are monoclinic, a = 11.413(2) Å, b = 10.981(2) Å, c = 14.385(3) Å, β = 105.90(3)°, V = 1733.8(6) ų, space group P2₁/n, R = 0.028 for 2797 reflections. Complex II is a dimer with bridging (NHCOCH₃)^? and (OH)^? groups. The Pt-Pt distance is 3.1667(7) Å.     

Di-μ-hydroxo bridge-cleavage reactions between [Co(nta)(μ-OH)]2 2− and different monodentate ligands

The cleavage of the di--hydroxo bridges of [Co(nta)(-OH)]₂ ^2– by dimethylaminopyridine (dmap) and pyridine (py) has been investigated. [Co(nta)(-OH)]₂ ^2– equilibrates rapidly in aqueous basic solutions with a mono--hydroxo bridged Co^III species [pK _OH = 3.26(2)] and both these species react with the incoming ligand to form different ion associated species which react in the subsequent rate-determining steps (k ₁ and k ₂) to form presumably a ligand-substituted, mono-bridged species, [(nta)(OH)Co--OH-Co(nta)(L)]^2–. Values for k ₂, the preferred mono--hydroxo bridged substitution pathway for these reactions, vary between 6.8(2) × 10^–4 s^–1 (py) and 8.5(4) × 10^–2 s^–1 (dmap).     

配合物[CO_2~ⅡCO_2~Ⅲ(μ_2-OH)_6(μ_2-HOAc)_2(AcO)_4)]的合成和表征

本文报导利用醋酸钴在酮类配位体存在下于冰醋酸溶剂中与氧分子作用,得到一种新型的对烃类的催化氧化具有良好的活性的催化剂。根据无素分析、差热热重分析、红外光谱、紫外可见光谱、质谱、核磁共振谱、磁化率和电导率等的测定结果,初步确定该配合物的结构是一种以羟基和羰基桥联的四核钴配合物[Co_2~ⅡCo_2~Ⅱ(μ_2-OH)_6(μ_2-HOAc)_2(AcO)_4]。     

SYNTHESIS AND SPECTRAL STUDIES OF(μ-PHENYLTHIO) (μ-ALKYLTHIO) HEXACARBONYLDIIRON COMPLEXES

Through reductive reaction between PhL1 and μ-S2 Fe (CO/6,tollowed by nucleophilicsubstitution of the intermediate (μ-PhS} (μ-LIS} Fe2 (CO)6 toward RX,nine Fe-S clus-ter complexes of (μ-PhS)(μ-RS)Fe2(CO)6 series have been synthesized.The influence of RX structures on the activities in nucleophilic substitution has been examined and possible steroisomers and isomer ratios of the complexes determined.In addition,the regular variations of isomer's CH3-S and CH2-S which are caused by the anisotropic effects of C-O and orientations of unshared electron pairs on sulfurs,have also been preliminarily discussed.     

双核锡配合物[Sn2Cl6(μ-OH)2(DMF)2]·4DMF的合成和晶体结构

A binuclear tin complex [Sn_2Cl_6(μ-OH)_2(DMF)_2]·4DMF has been synthesized through direct reaction of SnCl_4·5H_2O with DMF. Its molecular and crystal structure has been determined by single X-ray diffraction technique. The crystal is triclinic with space group P1. The unit cell parameters are a=0.9153(2), b=1.0722(3), c=1.2192(3) nm, α=63.07(2), β=93.26(2), γ=65.75 (2), V=0.92821(36) nm, D_c=1.649 g·cm~(-3), Z=1, The tin atom in the complex takes six-coordinated distorted octahedral configuration with sp~3 d~2 hybrid. The two tin atoms are connected through hydroxyl bridge to form a plane at the molecular center. The four noncoordinated DMF molecules distribute symmetrically around the dimer. The whole complex has an inversion center which coincides with the gravity center of the parallelogram.