Mononuclear,homo- and hetero-binuclear complexes of 1-(5-(1-(2-aminophenylimino)ethyl)-2,4-dihydroxyphenyl)ethanone: synthesis,magnetic, spectral,antimicrobial, antioxidant,and antitumor studies

A new Schiff base, H₂L, was prepared by condensation of 4,6-diacetylresorcinol with o-phenylenediamine in molar ratio 1?:?1. The ligand reacted with copper(II), nickel(II), cobalt(II), iron(III), zinc(II), oxovanadium(IV), and dioxouranium(VI) ions in the absence and presence of LiOH to yield mononuclear and homobinuclear complexes. The mononuclear dioxouranium(VI) complex [(HL)-(UO₂)(OAc)(H₂O)]·5H₂O was used to synthesize heterobinuclear complexes. The ligand and its metal complexes were characterized by elemental analyses, IR, ¹H-, and ¹³C-NMR, electronic, ESR and mass spectra, conductivity, and magnetic susceptibility measurements as well as thermal analysis. In the absence of LiOH, mononuclear complexes (1, 4, and 9) were obtained; in the presence of LiOH, binuclear complexes (3, 5, 7, and 10) as well as mononuclear complexes (2, 6, and 8) were obtained. In the mononuclear complexes, the coordinating sites are the phenolic oxygen, azomethine nitrogen, and amino nitrogen. In addition to these coordinating sites, the free carbonyl and phenolic OH are involved in coordination in binuclear complexes. The metal complexes exhibited octahedral, tetrahedral, and square planar geometries while the uranium is seven-coordinate. The antimicrobial and antioxidant activities of the ligand and its complexes were investigated. The ligand and the metal complexes showed antitumor activity against Ehrlich Acites Carcinoma.     

Construction of Mononuclear Copper(II) and Trinuclear Cobalt(II) Complexes Based on Asymmetric Salamo‐Type Ligands

Mononuclear copper(II) and trinuclear cobalt(II) complexes, namely [Cu(L¹)]₂ · CH₂Cl₂ and [{Co(L²)(EtOH)}₂Co(H₂O)] · EtOH {H₂L¹ = 4,6‐dichloro‐6′‐methyoxy‐2,2′‐[1,1′‐(ethylenedioxydinitrilo)dimethylidyne]diphenol and H₃L² = 6‐ethyoxy‐6′‐hydroxy‐2,2′‐[1,1′‐(ethylenedioxydinitrilo)dimethylidyne]diphenol}, were synthesized and characterized by elemental analyses, IR and UV/Vis spectroscopy, and single‐crystal X‐ray diffraction. In the Cu^II complex, the Cu^II atom is four‐coordinate, with a N₂O₂ coordination sphere, and has a slightly distorted square‐planar arrangement. Interestingly, the obtained trinuclear Co^II complex is different from the common reported 2:3 (L:Co^II) salamo‐type Co^II complexes. Infinite 2D layer supramolecular structures are formed via abundant intermolecular hydrogen bonding and π ··· π stacking interactions in the Cu^II and Co^II complexes.     

Anion Directed Self‐Assembly of One‐Dimensional and Two‐Dimensional Coordination Polymers Containing Bridging Diphosphine Ligands

The reactions of 1,2‐bis(diphenylphosphanyl)ethane (dppe) with different silver(I) salts facilitated the formation of 1D and 2D coordination polymers, [Ag(dppe)(OAc)]_n · nH₂O ( 1 ) and [Ag₂(dppe)_1.5(NO₃)₂]_n ( 2 ), respectively. The complexes were characterized by elemental analysis, ATR‐IR spectroscopy, ¹H NMR, ¹³C NMR, and ³¹P NMR spectroscopy, and single‐crystal X‐ray diffraction. Structural analysis revealed that complex 1 exhibits a 1D infinite wavy structure, in which each silver(I) ion is bridged by dppe ligands. Structure 2 has a 2D topologically promising architecture that displays a 6.6.6 graphitic net, which corresponds to hnd topology. The nitrate ions and dppe ligands are in a μ₂ bridging mode and support the formation of this net. Moreover, significant π–π interactions between the phenyl rings in the apertures of (6,3) grid stabilized complex 2 .     

Flexible CDOCKER: Development and application of a pseudo‐explicit structure‐based docking method within CHARMM

Protein‐ligand docking is a commonly used method for lead identification and refinement. While traditional structure‐based docking methods represent the receptor as a rigid body, recent developments have been moving toward the inclusion of protein flexibility. Proteins exist in an interconverting ensemble of conformational states, but effectively and efficiently searching the conformational space available to both the receptor and ligand remains a well‐appreciated computational challenge. To this end, we have developed the Flexible CDOCKER method as an extension of the family of complete docking solutions available within CHARMM. This method integrates atomically detailed side chain flexibility with grid‐based docking methods, maintaining efficiency while allowing the protein and ligand configurations to explore their conformational space simultaneously. This is in contrast to existing approaches that use induced‐fit like sampling, such as Glide or Autodock, where the protein or the ligand space is sampled independently in an iterative fashion. Presented here are developments to the CHARMM docking methodology to incorporate receptor flexibility and improvements to the sampling protocol as demonstrated with re‐docking trials on a subset of the CCDC/Astex set. These developments within CDOCKER achieve docking accuracy competitive with or exceeding the performance of other widely utilized docking programs. © 2015 Wiley Periodicals, Inc.     

5-(3-吡啶基)-1H-四氮唑配体构筑的[Ni_2(ptzH)_3(H_2O)_6]~(4+)二聚体修饰的八钼酸盐化合物

在水热条件下采用5-(3-吡啶基)-1H-四氮唑配体合成了基于八钼酸盐的有机-无机杂化化合物[Ni_2(ptz H)_3(H_2O)_6](β-Mo_8O_(26))·2H_2O(ptz H=5-(3-吡啶基)-1H-四氮唑),并通过单晶X-射线、元素分析和红外光谱对其进行了表征.化合物中存在β型八钼酸盐[Mo_8O_(26)]~)4-_和阳离子二聚体[Ni_2(ptz H)_3(H_2O)_6]~(4+)2个孤立的亚单元.在这个二聚体中,2个Ni原子被3个ptz H分子固定.相邻的Ni二聚体之间存在丰富的π…π堆积作用,形成1个带有菱形格子的二维超分子金属-有机层.[β-Mo_8O_(26)]~(4-)多阴离子通过提供大量的氢键作用而占据在该超分子二维层的菱形格子中.     

Synthesis,structure, thermostability and luminescence properties of ZnII and CdII coordination polymers based on dimethysuccinate and flexible 1,4‐bis(imidazol‐1‐ylmethyl)benzene ligands

The design and synthesis of functional coordination polymers is motivated not only by their structural beauty but also by their potential applications. Zn^II and Cd^II coordination polymers are promising candidates for producing photoactive materials because these d¹⁰ metal ions not only possess a variety of coordination numbers and geometries, but also exhibit luminescence properties when bound to functional ligands. It is difficult to predict the final structure of such polymers because the assembly process is influenced by many subtle factors. Bis(imidazol‐1‐yl)‐substituted alkane/benzene molecules are good bridging ligands because their flexibility allows them to bend and rotate when they coordinate to metal centres. Two new Zn^II and Cd^II coordination polymers based on mixed ligands, namely, poly[[μ₂‐1,4‐bis(imidazol‐1‐ylmethyl)benzene‐κ²N³:N^3′]bis(μ₃‐2,2‐dimethylbutanoato‐κ³O¹:O⁴:O^4′)dizinc(II)], [Zn₂(C₆H₈O₄)₂(C₁₄H₁₄N₄)]_n, and poly[[μ₂‐1,4‐bis(imidazol‐1‐ylmethyl)benzene‐κ²N³:N^3′]bis(μ₃‐2,2‐dimethylbutanoato‐κ⁵O¹,O^1′:O⁴,O^4′:O⁴)dicadmium(II)], [Cd₂(C₆H₈O₄)₂(C₁₄H₁₄N₄)]_n, have been synthesized under hydrothermal conditions and characterized by single‐crystal X‐ray diffraction, elemental analysis, IR spectroscopy and thermogravimetric analysis. Both complexes crystallize in the monoclinic space group C2/c with similar unit‐cell parameters and feature two‐dimensional structures formed by the interconnection of S‐shaped Zn(Cd)–2,2‐dimethylsuccinate chains with 1,4‐bis(imidazol‐1‐ylmethyl)benzene bridges. However, the Cd^II and Zn^II centres have different coordination numbers and the 2,2‐dimethylsuccinate ligands display different coordination modes. Both complexes exhibit a blue photoluminescence in the solid state at room temperature.