Mononuclear and Dinuclear Cobalt Complexes and its Dioxygen Adduct with a New 24-membered Hexaaza Macrocyclic Ligand

Abstract

Dinucleating 24-membered hexaazadiphenol macrocyclic ligand 3,6,9,17,20,23-hexaaza-29,30-dihydroxy-13,27-dimethyl-tricyclo[23,3,1,1^11,15] triaconta-1(29), 11,13,15(30),25,27-hexaene (L or BDBPH), is prepared by the NaBH₄ reduction of the Schiff base obtained from [2+2] template condensation of 2,6-diformyl-p-cresol with diethylenetriamine. The ligand maintains dinuclear integrity for cobalt (II) while facilitating the formation of bridging phenolate dicobalt cores. Potentiometric equilibrium studies indicate that a variety of protonated, mononuclear and dinuclear cobalt (II) complexes form from p[H] 2 through 11 in aqueous solution. The protonation constants of this ligand and stability constants of the 1:1, 1:2 ligand: cobalt(II) complexes were determined in KCl supporting electrolyte (μ = 0.100 M) at 25°C. The mechanism for the formation of dinuclear dioxygen cobalt(II) complexes is also described. The stability constants of mononuclear and dinuclear cobalt complexes were determined under nitrogen. Preliminary results show that the dinuclear dioxygen cobalt (II) complexes do not catalyze hydroxylation of adamantane in the presence of H₂S as two-electron reductant.     

Synthesis and Characterization of Dinuclear Aluminum Complexes Bearing N,N-Dialkylaniline-amido Ligands and Its Catalytic Properties for Lactone Polymerization

Two ligands [ortho-C6H4NR2（CH2NH）]2CH2CH2（3： R=Me; 4： R=EO were prepared by the reduction of preligands [ortho-C6H4NR2（CH=N）]zCH2CH2（1： R=Me; 2： R=Et）. These ligands reacted with AIMe3 to afford the corresponding dinuclear aluminum complexes {A1Me2[ortho-C6H4NR2（CH2N）]}2CHzCH2（5： R=Me; 6： R=Et）. All the compounds were characterized by 1H and UC nuclear magnetic resonance（NMR） spectroscopies and elemental analyses. The catalytic properties of the aluminum complexes towards the ring-opening polymerization of lactones were investi- gated in the presence of benzvl alcohol. All the oolvmerization reactions were proceeded in a controlled manner.     

Synthesis and Structure of a New Dinuclear Uranyl Complex

Dinuclear complexes have been widely investigated since 1970s when Robson proposed the conception of dinucleating ligand1,2. These compounds attracted much interests because of their applications as metal-enzemy model in bioinorganic chemistry or promising applications as functional materials. Most of these dinuclear complexes contain d transition metals as central ions. Few dinuclear U complexes have been reported. It is known, in most complexes of axial ion, five donors from ligands shou…     

Preparation and Characterization of Dinuclear Chromium(III) Complexes of a Hexadentate Tetraaza‐Dithiophenolate Ligand

The ability of the tetraaza‐dithiophenolate ligand H₂L² (H₂L² = N,N′‐Bis‐[2‐thio‐3‐aminomethyl‐5‐tert‐butyl‐benzyl]propane‐1,3‐diamine) to form dinuclear chromium(III) complexes has been examined. Reaction of Cr^IICl₂ with H₂L² in methanol in the presence of base followed by air‐oxidation afforded cis,cis‐[(L²)Cr^III₂(μ‐OH)(Cl)₂]⁺ ( 1a ) and trans,trans‐[(L²)Cr^III₂(μ‐OH)(Cl)₂]⁺ ( 1b ). Both compounds contain a confacial bioctahedral N₂ClCr^III(μ‐SR)₂(μ‐OH)Cr^IIIClN₂ core. The isomers differ in the mutual orientation of the coligands and the conformation of the supporting ligand. In 1a both Cl^? ligands are cis to the bridging OH function. In 1b they are in trans‐positions. Reaction of the hydroxo‐bridged complexes with HCl yielded the chloro‐bridged cations cis,cis‐[(L²)Cr^III₂(μ‐Cl)(Cl)₂]⁺ ( 2a ) and trans,trans‐[(L²)Cr^III₂(μ‐Cl)(Cl)₂]Cl ( 2b ), respectively. These bridge substitutions proceed with retention of the structures of the parent complexes 1a and 1b .     

Synthesis and Structures of Two Dinuclear Transition Metal Complexes and Their Catalytic Applications in Hydrogenation of Ketones

The complexes [Ni₂(L)₂]₂ · H₂O ( 1 ) and [Cu₂(L)₂(H₂O)] · 2CH₃OH ( 2 ) were prepared by reaction of the chiral Schiff base ligand N‐[(1R,2S)‐2‐hydroxy‐1,2‐diphenyl]‐acetylacetonimine (H₂L) with Ni^II and Cu^II ions, respectively, aiming to develop economically and environmentally‐friendly catalysts for the hydrogenation of ketones. They have a dinuclear skeleton with axial vacant sites. The catalytic effects of the two complexes for hydrogenation of ketones were tested using dihydrogen gas as hydrogen source. They present some catalytic effects in hydrogenation of acetophenone, which has a dependence on the temperature and base used in these reactions. However, no apparent catalytic effects were found for the two complexes in hydrogenation of 4‐nitroacetophenone and 4‐methylacetophenone. Although the catalytic conversion in these hydrogenation reactions is low, they do represent a kind of cheap and environmentally‐friendly hydrogenation catalyst.     

Magnetic and Luminescence Properties of Two Dinuclear Lanthanide Complexes with Butterfly‐like Arrangement

Two dinuclear lanthanide complexes with pentadentate ligand 3‐[bis(pyridine‐2‐ylmethyl)amino]propane‐1,2‐diol (H₂L), formulated as [Ln₂(HL)₂(NO₃)₂(H₂O)₂] · 1.5NO₃ · 0.5I [Ln = Tb ( ZTU‐1 ) and Eu ( ZTU‐2 ); ZTU = Zhaotong University] were synthesized and structurally characterized. ZTU‐1 and ZTU‐2 are isomorphous and feature a butterfly‐like arrangement. The fluorescence properties of ZTU‐1 and ZTU‐2 are investigated and slow magnetic relaxation behavior is observed in ZTU‐1 .     

具有不同类型桥基的双核Cu(Ⅱ)-Schiff碱配合物的合成和晶体结构

合成了３个分别以Ｃ２Ｏ２－４（［Ｃｕ２（Ｌ１）２（ｏｘ）］，１），ＡｃＯ－（［Ｃｕ２（ＡｃＯ）（Ｌ２）２］ＢＦ４，２）和酚氧（［Ｃｕ２（Ｌ３）２］（ＣｌＯ４）２，３）为桥基的双核铜配合物，并测定了１的复配合物［Ｃｕ２（Ｌ１）２（ｏｘ）］·［Ｆｅ（ＯＨ）２（Ｈ２Ｏ）４］ＣｌＯ４·Ｈ２Ｏ（１′）及２和３的晶体结构．Ｘ射线衍射结果表明：１′，２和３分别属于Ｆｄｄｄ，Ｐ２１／ｃ和Ｐ２１／ｃ空间群．晶胞参数：［Ｃｕ２（Ｌ１）２（ｏｘ）］［Ｆｅ（ＯＨ）２（Ｈ２Ｏ）４］ＣｌＯ４·Ｈ２Ｏ，ａ＝２．４３９０（４）ｎｍ，ｂ＝３．０５３８（６）ｎｍ，ｃ＝１．８４９４（６）ｎｍ，α＝β＝γ＝９０．００°；２，ａ＝０．８４７（１）ｎｍ，ｂ＝２．６５４２（８）ｎｍ，ｃ＝１．４１００（６）ｎｍ，β＝９１．３４（６）°；３，ａ＝０．７６４６（３）ｎｍ，ｂ＝１．６９８３（３）ｎｍ，ｃ＝２．４４１７（３）ｎｍ，β＝９７．１１°     

Synthesis and Characterization of Novel Template Complexes

Novel neutral polynuclear Ni^II chelates of L ‐cysteine (L ‐cyst) or D ‐penicillamine (D ‐pen) with dicyandiamide (dcda) were synthesized and characterized using elemental analysis, UV, CD, reflectance, and IR spectroscopy and/or thermogravimetric and X‐ray analysis. The obtained dinuclear compounds add important information about the chemistry of nickel(II) ions, which form types of bonds that cannot be obtained with other metal ions such as Co^II. These dinuclear nickel compounds contain four‐membered rings with two sulfur and two nickel atoms. Electronic transitions were elucidated from reflectance, CD and absorbance spectroscopy and confirm a distorted square planar arrangement of the nickel ions. Because the same structure with Co^II ions could not be obtained directly, dimethylglyoxime was added to a suspension of the template complex with D ‐pen in water to separate the nickel ions. The separation of the ligand was confirmed by elemental analysis, IR, and ¹H NMR spectroscopy. It reacted with Co^II to give a different mononuclear crystalline complex that was studied by X‐ray single crystal diffraction. The crystals are orthorhombically with space group C222₁, a = 0.11769(4) pm, b = 0.13632(4) pm, c = 0.25239(8) pm, V = 0.0040490(2) pm³, and Z = 8.     

Synthesis,Structure and Characterization of Dinuclear Pentacoordinate Molybdenum(V) Complexes with Thiosemicarbazone Ligands

New dinuclear pentacoordinate molybdenum(V) complexes, [Mo₂^VO₃L₂] [L = thiosemicarbazonato ligand: C₆H₄(O)CH:NN:C(S)NHR′ and C₁₀H₆(O)CH:NN:C(S)NHR′; R′ = H, CH₃, C₆H₅) were obtained either by oxygen atom abstraction from Mo^VIO₂L with triphenylphosphine or by using [Mo₂O₃(acac)₄] in the reaction with the corresponding ligands H₂L. Crystal and molecular structure of [Mo₂O₃{C₆H₄(O)CH:NN:C(S)NHC₆H₅}₂] · CH₃CN has been determined by the single‐crystal X‐ray diffraction method.     

Synthesis and Structural Characterization of Dinuclear Oxorhenium(V) Complexes with Bidentate Imidazole Derivatives

The oxo-bridged dinuclear complexes [(μ-O){ReOCl₂(L)}₂] [L = 2-(1-ethylaminomethyl)-1-methylimidazole (eami); 2-(1-methylaminomethyl)-1-methylimidazole (mami); 2-(1-ethylthiomethyl)-1-methylimidazole (etmi)] were prepared by reaction of trans-[ReOCl₃(PPh₃)₂] with L in acetone. X-ray crystallographic studies of the eami and etmi complexes show that these ligands coordinate in a bidentate manner, and that the cis, cis-N₂Cl₂ and cis, cis-NSCl₂ equatorial planes are nearly orthogonal to the O=Re-O-Re=O backbone.     

Synthesis and Crystal Structure of a Dinuclear Titanium(IV) Complex containing an Allopyranosidato Ligand

The reaction of methyl‐4,6‐O‐benzylidene‐α‐D ‐allopyranoside (α‐MeBAH₂) with trichlorocyclopentadienyltitanium [CpTiCl₃] and triethylamine in dichloromethane led to the dinuclear complex [(CpTiCl₂)₂‐μ‐(α‐MeAG)] ( 1 ). 1 was characterized by elemental analysis, ¹H NMR spectroscopy as well as single crystal X‐ray diffraction.     

1,4,7-三氮杂环癸烷过渡金属配合物的合成与结构表征

以十元环大环三胺配体1,4,7-三氮杂环癸烷(tacd)为主配体,分别与钴、镍、铜和锌的顺丁烯二酸盐和己二酸盐进行反应,得到了8种含有双大环的单核配合物,利用元素分析,红外光谱以及热重分析等手段对它们的结构进行了表征.结果表明这八种配合物具有类似的配位结构.     

Synthesis and Characterization of Dinuclear Rare Earth Complexes Bearing N-heterocyclic Olefin Moieties

The oxygen-bridged dinuclear rare earth complexes(Ln=Nd(1),Y(2))bearing N-heterocyclic olefin moieties were synthesized by treating the imidazolidinium salt[SIMes-H]Br with potassium amide and rare earth bis(trimethylsilyl)amides.Complex 1 was characterized by X-ray diffraction analysis and complex 2 was characterized by 1H NMR spectroscopy.Both complexes were characterized by elemental analysis.Crystal data of complex 1:C74H138O2N8Si8Nd2,Mr=1685.12,orthorhombic,space group Pbca,a=25.1105(7),b=11.9188(2),c=29.6151(7)?,V=8863.4(4)?^3,Z=4,Dc=1.263 g·cm^-3,μ=1.311 mm^-1,F(000)=3544,the final R=0.0418 and wR=0.0770 for all data.The ring-opening of tetrahydrofuran molecule was proven,the possible mechanism for the formation of N-heterocyclic olefin(NHO)-rare earth complexes was speculated and the electronic and steric properties of SIMes and rare earth amides were discussed.This work provides a better understanding of N-heterocyclic carbene rare earth chemistry.     

Synthesis, Photophysical and Electrochemical Characterization of the Heteroleptic Iridium Complexes with Modified Ancillary Ligand by Carrier-transporting Groups

Two heteroleptic iridium complexes with a general formulation of (piq)₂Ir(G‐pic) were synthesized and characterized by ¹H NMR, ¹³C NMR and element analysis, in which piq is 1‐phenylisoquinoline, G‐pic is picolinic acid derivative containing carrier‐transporting group by a non‐conjugated connection of 1,6‐dioxyhexane. Both (piq)₂Ir(G‐pic) complexes exhibited an enhanced UV absorption band at 310–400 nm, an increased HOMO energy level and an identical red emission peaked at 612 nm with higher fluorescence quantum efficiency (ø_f), compared to (piq)₂Ir(pic) in dichloromethane solution. Interestingly, this iridium complex containing both hole‐transporting triphenylamine and electron‐transporting oxadiazole moieties exhibited the best Ф_f of 0.58 using Ru(bpy)₃(PF6)₂ as the reference (ø_f=0.062 in acetonitrile). This work indicates that incorporating carrier‐transporting groups into ancillary ligand by a non‐conjugated connection is available for improving the optophysical properties of their iridium complexes.     

萘啶酮的单核和双核银配合物的合成与晶体结构

合成了萘啶酮的单核和双核银配合物Ag₂(L₁)₂(HL₁=5，7-二甲基-1，8-萘啶-2-酮) (1)和[Ag(HL₂)(PPh₃)₂]·2H₂O(H₂L₂=1，8-萘啶-2,7-二酮) (2)。并通过元素分析，红外光谱及X-射线单晶衍射对其进行了结构表征。配合物1的晶体属单斜晶系，P1空间群。中心金属银为三配位T型几何构型，Ag-Ag间距离为0.274 8(2) nm，具有强的Ag…Ag作用。配合物2的晶体属三斜晶系，P2₁/n空间群。银与1个氮原子及2个磷原子形成三配位结构。     

邻氨基苯酚Schiff碱多核配合物的合成与表征

合成了3-羧基水杨醛缩邻氨基苯酚Sch iff碱及其三核铜,三核镍配合物.用质谱分析,核磁共振,红外光谱,元素分析对配体和配合物的结构进行了表征.磁性研究表明,这两种配合物的金属离子间均存在着较强的反铁磁性自旋交换相互作用.     

含桥式硫原子双酚盐配体的有机铋配合物的合成及其对CO2和环氧丙烷环加成反应催化性能的研究

合成分析了含有桥式硫原子二酚盐配体的新型有机铋配合物,并发现它们在亲核试剂(I-)存在下对CO2和环氧丙烷环加成反应合成碳酸丙烯酯表现出很高的催化活性和选择性.     

吡唑-3,5-二(N-烷基甲酰胺)类配体的双核铜配合物的磁性质和电子结构

合成了以双吡唑桥联的双核铜配合物的3个同系物。利用吡唑-3,5-二(N-甲基甲酰胺)合硝酸铜双聚物的粉末ESR谱计算了g_∥和g_⊥。变温磁化率的实验数据拟合表明了它们均为有较强反铁磁性的化合物,用半经验分子轨道方法分析了它们的磁交换途径。     

新型含N-杂环卡宾二硫化碳配体的锰铼金属双核化合物的合成、表征及电化学性质简

合成了一系列含N-杂环卡宾二硫化碳加合物配体的锰铼金属有机化合物,其中包括3种单核化合物和3种双核化合物,对它们的结构进行了表征,并研究其反应性和电化学性质. 与三烷基膦二硫化碳配体相比,含N-杂环卡宾二硫化碳加合物配体的锰铼金属有机化合物展现出不同的反应特性. 研究结果表明,[MnRe(CO)6(μ-H){μ-CH3SC(S)IMes2}]配合物具有催化质子还原成氢气的能力.     

Synthesis and Characterization of Novel Aliphatic Polycarbonates Bearing Pendant Allyl Ether Groups

To fulfill the diverse requirements in surgery and medicine, biomedical polymers have been drawing interests and attentions increasingly since the last decade1. In these fields, aliphatic carbonates have been proved to be a kind of material with excellent…