光(热)致变色剂:单和双吲哚啉螺苯并吡喃

用乙醇作溶剂,在哌啶存在下,通过2,3,3-三甲基-N-(β-羟乙基)吲哚啉碘化物(1)与3-或5-硝基水杨醛反应,分别制得螺环异构体(2a)与(2b)。它们再进一步与异氰酸苯酯进行加成反应,合成一对单螺环异构体(3a)与(3b),将2a 与2b 分别和2,4-二异氰酸甲苯酯(TDI)反应,合成一对双螺环异构体(4a)与(4b)。2a,3a,4a,4b 是光致变色化合物;2b 与3b 是热致变色化合物。     

Novel large heteropolymetalate complexes formed from Ni(II) and cryptate [As<Subscript>4</Subscript>W<Subscript>40</Subscript>O<Subscript>140</Subscript><Superscript>28-</Superscript>

The heteropolytungstate (NH4)₂₀[Na2(H₂O)₂Ni(H₂O)₅{Ni(H₂O)}₂As₄W₄₀O₁₄₀] · 61H₂O is obtained by the reaction of Na₂₇[NaAs₄W₄₀O₁₄₀] · 60H₂O with NiCl₂ · 6H₂O and NH₄Cl in pH≈4.0. The structure and chemical composition are determined by X-ray diffraction analysis and element analysis. The crystal data and main structure refinement are: a = 1.33135(18) nm, b = 1.9722(3) nm, c = 3.6430(5) nm, α = 78.010(2)°, β = 82.145(2)δ, γ = 74.385(2)°, V = 8.978(2) nm³, triclinic crystal system, space group: P1, Z = 2, R1 = 0.0512, and wR2 = 0.0684(I >2σ). The four S2 sites of the big cyclic ligand [As₄W₄₀O₁₄₀]^28- are occupied by two Na⁺ and two Ni²⁺ respectively, and each site supplies four O_d coordinating to metal ion. The coordination number of Ni²⁺ is six, and that of two Na⁺ is five and six respectively. The third Ni²⁺ locates outside the cyclic [As₄W₄₀O₁₄₀]^28- and connects with one O_d, and its coordination number is six.     

Insights into the interactions between DNA and an infinite clamp-like copper (II) complex

Transition Metal Chemistry - A Cu(II) complex [Cu2(phen)2(NAB)2(HO)]n (phen?=?1, 10-phenanthroline and NABH?=?p-N, N-(2-hydroxyethyl)amino benzoic acid) was synthesized, and...     

Syntheses and Structural Characterization of 1D Chain and 1D Ladder Coordination Polymers Assembled from Exo‐bidentate Imidazolyl Ligands

Five novel coordination polymers, [(Cu(L¹)₂OH) · Cl · 3H₂O] ( 1 ) [L¹ = bis(N‐imidazolyl)methane], [Cd(L¹)₂(NCS)₂] ( 2 ), [Zn(L¹)₂(NCS)₂] ( 3 ), [Cu(L¹)₂(NO₃)₂] ( 4 ), and [Cu(L²)_1.5(NCS)₂] ( 5 ) [L² = 1,4‐bis(N‐imidazolyl)butane] were obtained from self‐assembly of the corresponding metal salts with flexible ligands and their structures were fully characterized by X‐ray diffraction (XRD) analysis, Fourier Transform Infrared (FT‐IR) spectroscopy, elemental analysis and thermogravimetric (TGA) measurements. X‐ray diffraction analyses revealed that complexes 1 , 2 , 3 , and 4 exhibit 1D double‐stranded chain structures, which result from doubly bridged [CuOH], [M(NCS)₂] (M = Cd, Zn), and [Cu(NO₃)₂] units, respectively. The polymeric copper complex 5 displays 1D ladder structure., These complexes, with the exception of complex 1 , are stable up to 300 °C.     

One Porous Supramolecular Complex Assembled from Ionic and Neutral Hydrogen-bonds of N–H···O and C–H···O

Abstract  

The imidazolyl derived complex N,N′-butylenebis(imidazole):(oxalic acid)_0.5 was prepared and structurally characterized by X-ray crystallography. The title compound crystallizes in the triclinic, space group P-1, with a = 4.4373(9) ?, b = 12.882(3) ?, c = 15.319(3) ?, α = 99.91(3)°, β = 94.53(3)°, γ = 98.72(3)°, V = 847.7(3) ?³, Z = 2. Two N,N′-butylenebis(imidazole) and two oxalic acid molecules form an annulus via intermolecular hydrogen bonds, with internal dimensions of about 7.1 × 11.1 ?. Neighboring annuluses were connected by N–H···O and C–H···O interactions to form 1D double chain structure. Adjacent double chains stacked just above each other along the a-axis direction, this arrangement of the double chains leads the extended supramolecular architecture to show a three-dimensional porous network.     

Synthesis and Structural Characterization of Four Zinc Complexes Containing 3,5‐Dimethylpyrazole and Carboxylate Ligands

Four new zinc(II) complexes Zn₂(μ‐dmpz)₂(Hdmpz)₂(L1)₂ ( 1 ) (Hdmpz = 3,5‐dimethylpyrazole, HL1 = 2‐methyl‐2‐phenoxypropanoic acid), Zn(Hdmpz)₂(L2)₂ ( 2 ) [HL2 = 2‐hydroxy‐5‐(phenyldiazenyl)benzoic acid], Zn₂(μ‐dmpz)₂(Hdmpz)₂(L3)₂ ( 3 ) [HL3 = 3,4‐(methylenedioxy)benzoic acid], and Zn₂(μ‐dmpz)₂(Hdmpz)₂(L4)₂ ( 4 ) [HL4 = 3‐(4‐methoxyphenyl)acrylic acid] were prepared and structurally characterized by different techniques including elemental analysis, IR spectroscopy, and single‐crystal X‐ray diffraction analysis. The X‐ray studies suggested that all these complexes except compound 2 are centrosymmetric dinuclear complexes with a tetrahedral arrangement around each zinc ion, whereas compound 2 is a mononuclear complex. The pyrazole ligand is coordinated in both terminal as well as a bridging fashion in the dinuclear moiety, whereas the pyrazole ligand in compound 2 is coordinated only in monodentate terminal fashion with its neutral nitrogen group. In all four complexes the carboxylate functions behave as monodentate ligands. All complexes show intramolecular hydrogen bonding of N–H ··· O between N–H of pyrazole and nonbonded oxygen atom of carboxylate. Furthermore, rich intermolecular weak interactions such as classical hydrogen bonds, C–H ··· O, C–H ··· N, C–H ··· π, and CH₃–π interactions exist and complexes 1 – 4 display a set of 3D superamolecular frameworks. In addition, the four compounds are thermally stable below 150 °C.