Syntheses,crystal structures,and luminescent properties of two cadmium(II) complexes based on bis(imidazole) and dicarboxylate

Two complexes, [Cd(ip–OH)(H₂biim)(H₂O)][Cd(ip–OH)(H₂biim)(H₂O)₃]·8(H₂O) (1) and [Cd(Himdc)(H₂biim)] _n (2) (H₂ip–OH?=?5-hydroxylisophthalic acid, H₂biim?=?2,2’-biimidazolate, H₃imdc?=?4,5-imidazoledicarboxylic acid), have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. 1 is a 3-D supramolecular network constructed by 0-D and 1-D motifs through hydrogen bonds and π?π interactions. Complex 2 is a 1-D zigzag polymeric coordination chain and the chains are connected to form a 3-D supramolecular network by hydrogen bonds. The complexes were characterized by elemental and thermogravimetric analyses. Fluorescence was also investigated.     

Reduction of tri(hetero)arylcarbinols to tri(hetero)arylmethanes

Summary A series of seven new tri(hetero)arylmethanes has been prepared by reduction of the corresponding carbinols using a mixture of lithium aluminium hydride/aluminium trichloride. The yields are excellent (77–98%) except in the case of the tri(2-benzothienyl)derivative (41%).¹H NMR spectra are discussed.

---

Reduktion von Tri(hetero)arylcarbinolen zu Tri(hetero)arylmethanen

Zusammenfassung Durch die Reduktion der entsprechenden Carbinole mit Lithium-aluminiumhydrid/Aluminiumchlorid wurden sieben neue Tri(hetero)arylmethane in sehr guten Ausbeuten (77–98%) hergestellt. Eine Ausnahme bildet das Tri-(2-benzothienyl)-Derivat mit 41%. Die¹H-NMR-Spektren werden diskutiert.

     

A new luminescent 3-D metal-organic framework of diamond-like network possessing 8-fold interpenetration

A new 3-D coordination polymer [Zn(L)₂] (1) (HL?=?4-(pyridin-4-ylmethoxy)benzolic acid) was synthesized under hydrothermal conditions with Zn(OAc)₂?·?2H₂O and HL and characterized by single crystal X-ray diffraction (XRD). Compound 1 displays a 3-D 8-fold interpenetrating structure with diamondoid framework containing large adamantanoid cages. Meanwhile, it exhibits intense fluorescence at 402?nm in the solid state. In addition, powder XRD and thermogravimetric (TG) analysis for 1 are also reported.     

Zinc(Ⅱ) coordination architectures based on 5-(1H-tetrazol-1-yl)-isophthalic acid:Synthesis,structures and luminescent properties

With different pyridine-analogs as auxiliary ligands,three novel Zn(Ⅱ) complexes(1-3) based on 5-(1Htetrazol-1-yl) isophthalic acid(H_2L) have been synthesized and structurally characterized.Single crystal X-ray diffraction analyses of complexes 1-3 show the presence of tetrazolyl group,as well as the coordination behavior of the auxiliary ligands as critical factors determining the structures of such Zn(Ⅱ)-carboxyIate coordination architectures.In addition,the resulting complexes all exhibit luminescence properties in the solid state at room temperature.     

Two transition metal supramolecular compounds based on 2-(4-isopropylbenzoyl)benzoic acid: syntheses,crystal structures,and luminescent properties

Two new supramolecular compounds, [Zn₂(L)₃(4,4′-bpy)(OH)]_n (1) and [Cd(L)₂(2,2′-bpy)(H₂O)]·2H₂O (2) (HL?=?2-(4-isopropylbenzoyl)benzoic acid, 4,4′-bpy?=?4,4′-bipyridine, 2,2′-bpy?=?2,2′-bipyridine), have been hydrothermally synthesized and characterized by elemental analysis, infra-red spectroscopy, thermal gravimetric analyzes, and single-crystal X-ray diffraction. 1 exhibits 1-D chain and 2 is 0-D mononuclear. They are both linked into 2-D supramolecular layers by non-covalent interactions. Luminescence properties were also investigated.     

Syntheses,structures, and luminescent properties of Zn(II) and Cd(II) complexes: 3-D supramolecules based on 2,6-bis(imino)pyridine ligands constructed by hydrogen bonding interactions

Six 5-coordinate 2,6-bis(imino)pyridine metal complexes, [2,6-(ArN=CMe)₂C₅H₃NMCl₂ · nCH₃CN] (Ar = 4-MeC₆H₄, M = Zn, n = 0.5, Zn1, M = Cd, n = 1, Cd1; Ar = 2,6-Et₂C₆H₃, M = Zn, n = 0.5, Zn2, M = Cd, n = 0.5, Cd2; Ar = 2,4,6-Me₃C₆H₂, M = Zn, n = 1, Zn3, M = Cd, n = 1, Cd3), were synthesized in acetonitrile by the reactions of the corresponding bis(imino)pyridines with ZnCl₂ or CdCl₂ · 2.5H₂O, respectively. The structures of Zn1–Zn3 and Cd1–Cd3 were determined by the single-crystal X-ray diffraction. In all complexes, the ligand is tridentate with further coordination by two chlorides, resulting in a distorted trigonal bipyramid. All complexes self-assemble through hydrogen bonding interactions to form a 3-D supramolecular structure. At 298 K in dichloromethane, all complexes have blue luminescent emissions at 405–465 nm, which can be attributed to ligand-centered π* → π transitions. The zinc and cadmium centers play a key role in enhancing fluorescent emission of the ligands.     

Synthesis, structures and luminescent properties of Co(II) and Ni(II) metal-organic frameworks with semirigid diphthalic ligands

A series of transition metal coordination polymers [Co(H₃L)₂(4,4′- bpy)(H₂O)₂]_n?n(4,4′-bpy) (1), [Ni(H₂L)(4,4′-bpy)(H₂O)₂]_n (2), [Co₂(L)(phen)₂(H₂O)₄]_n?(H₂O)_2n (3), and [Ni₂(L)(phen)₂(H₂O)₄]_n?(H₂O)_2n (4) have been assembled from a semirigid multicarboxylate ligand 3,3′-(1,4-phenylenebis(oxy))diphthalic acid (H₄L) with the help of 4,4′-bipyridine (4,4′-bpy) ligand or 1,10-phenanthroline (phen) ligand. X-ray single crystal diffraction analysis reveals that complex 1 crystallizes in the space group of P − 1 and displays a one-dimensional (1D) chain structure constructed from 4,4′-bpy ligand and H₃L ligand, which was further interlinked to form a three-dimensional network via hydrogen bonds. In complex 2, Ni(II) atoms are coordinated by L ligand in monodentate fashion to form alternate left- and right-helices, which are further bridged together by the coordination interactions between Ni(II) atoms and 4,4′-bpy, leading to a 2-fold (4, 4)-connected interpenetrating network. Isostructural complexes 3 and 4 belong to the space group P − 1 and display a 1D chain structure constructed from phen and L ligands, which was further interlinked to form a 2D plane via π–π interactions. In addition, their thermal and luminescent properties were also investigated.     

Two Cd(II) complexes derived from mercapto-triazole ligands: syntheses,crystal structures,and luminescent properties

Two cadmium complexes, {[Cd(a-ptt)(ptt)]·H₂O} _n (1) and [Cd(a-Hmtt)₂(SO₄)H₂O]·CH₃OH (2), have been prepared based on 4-amino-3-(4-pyridine)-5-mercapto-1,2,4-triazole (a-Hptt) and 4-amino-3-methyl-5-mercapto-1,2,4-triazole (a-Hmtt), respectively. In 1, amino-triazole ligand a-Hptt can partly be deaminated and transformed into 3-(4-pyridine)-5-mercapto-triazole (Hptt) under hydrothermal conditions. X-ray diffraction analysis reveals that 1 exhibits an unusual 2-D lampshade-type layer structure in which the amino ligand a-ptt and the deamination ligand ptt display exo-tridentate bridging and bidentate bridging, respectively. Complex 2 is mononuclear and further assembled into a 3-D supramolecular architecture via non-covalent interactions. Complexes 1 and 2 were characterized by elemental analyses, IR, and thermogravimetric analyses. Furthermore, solid-state luminescent properties of 1 and 2 have also been investigated.     

Three isomeric copper(II) coordination polymers based on a bis-triazole-bis-amide ligand: Assembly,structures, and luminescent properties

Three copper(II) isomers, [Cu(dtcd)(DNBA)₂]_n (1–3) (HDNBA = 3,5-dinitrobenzoic acid, dtcd = N,N-di(4H-1,2,4-triazole)cyclohexane-1,4-dicarboxamide), were synthesized in a one-pot reaction, and structurally characterized. Polymer 1 shows a 1-D single chain in which dtcd connect adjacent Cu²⁺ ions, while DNBA^? is monodentate. In 2, every two Cu²⁺ ions are linked by carboxylate of a DNBA^? in a chelate-bridging mode into a binuclear unit, which is further connected by dtcd ligands into a 1-D double chain. In 3, dtcd connect Cu²⁺ ions via triazole nitrogens to generate 1-D single chains, which are further extended into a 2-D network by the amide oxygens of a dtcb from an adjacent chain. The pH plays an important role in product distribution of 1–3. The coordination behaviors of dtcd and DNBA^? also influence the final structures. Luminescent properties of 1–3 have been investigated.     

Synthesis and spectral characterization of zinc(II) and cadmium(II) complexes of acetone-N(4)-phenylsemicarbazone: Crystal structures of acetone-N(4)-phenylsemicarbazone and a cadmium(II) complex

Seven Zn(II) and Cd(II) complexes of ON donor acetone-N(4)-phenylsemicarbazone (HL) have been synthesized and physico-chemically characterized by partial elemental analyses, molar conductance measurements, infrared, electronic and ¹H NMR spectral studies. The semicarbazone binds the metal as a neutral bidentate ligand in all the complexes. The crystal structures of acetone-N(4)-phenylsemicarbazone and [Cd(HL)₂Cl₂] have been determined by X-ray diffraction studies. The coordination geometry around cadmium(II) in the complex [Cd(HL)₂Cl₂] is distorted octahedral.     

Architectural diversity of six coordination compounds based on (S)-(+)-mandelic acid and different N-donor auxiliary ligands: syntheses,structures, and luminescent properties

Six transition metal coordination compounds with H₂mand and different N-donor ligands, [Co(Hmand)₂(2,2′-bipy)]·H₂O (1), [Ni(Hmand)₂(2,2′-bipy)]·H₂O (2), [Ni(Hmand)₂(bpe)] (3), [Zn(Hmand)₂(2,4′-bipy)(H₂O)]·2H₂O (4), [Zn(Hmand)(bpe)(H₂O)]_n[(ClO₄)]_n·nH₂O (5), and [Zn(Hmand)(4,4′-bipy)(H₂O)]_n[(ClO₄)]_n (6), were synthesized under different conditions (H₂mand = (S)-(+)-mandelic acid, bpe = 1,2-di(4-pyridyl)ethane, 4,4′-bipy = 4,4′-bipyridine, 2,4′-bipy = 2,4′-bipyridine, 2,2′-bipy = 2,2′-bipyridine). Their structures were determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, infrared spectra, thermogravimetric analysis, powder X-ray diffraction, and circular dichroism. Compounds 1 and 2 are isostructural (0-D structures), which are extended to supramolecular 1-D chains by hydrogen bonding. Compound 3 exhibits 1-D straight chain structures, which are further linked via hydrogen bond interactions to generate a 3-D supramolecular architecture. Compound 4 displays a discrete molecular unit. Neighboring units are further linked by hydrogen bonds and π–π interactions to form a 3-D supramolecular architecture. Compound 5 displays a 2-D undulated network, further extended into a 3-D supramolecular architecture through hydrogen bond interactions. Compound 6 possesses a 2-D sheet structure. Auxiliary ligands and counteranions play an important role in the formation of final frameworks, and the hydrogen-bonding interactions and π–π stacking interactions contributed to the formation of the diverse supramolecular architectures. Compounds 1, 2, 4, 5, and 6 crystallize in chiral space groups, with the circular dichroism spectra exhibiting positive cotton effects. Furthermore, the luminescent properties of 4–6 have been examined in the solid state at room temperature, and the different crystal structures influence emission spectra significantly.     

Synthesis and structural characterisation of cobalt(II) and iron(II) chloride complexes containing bis(2-pyridylmethyl)amine and tris(2-pyridylmethyl)amine ligands

Treatment of (2-C₅H₄N)CH_{2 3}N (TPA) with one equivalent of MCl₂ in n-BuOH at elevated temperatures affords the six-coordinate complexes [(TPA)MCl₂] (M = Co (1), Fe (2)) and, in the case of CoCl₂, the five-coordinate chloride salt [(TPA)CoCl]Cl (3). Conversely, addition of an excess of CoCl₂ in the latter reaction leads to [(TPA)CoCl]₂[CoCl₄] (4) as the only isolable product. Interaction of one equivalent of (2-C₅H₄N)CH_{2 2}NH (DPA) and MCl₂ under similar reaction conditions to that described above affords the dimeric species [(fac-DPA)MCl(μ-Cl)]₂ (M = Co (5), Fe (6)), while the bis(ligand) halide salts [(fac-DPA)₂M]Cl₂ (M = Co (7), Fe (8)) are accessible on addition of two equivalents of DPA. In the presence of air, 6 undergoes oxidation to give [ (fac-DPA)FeCl_{2 2}(μ-O)] (9). Single-crystal X-ray diffraction studies are reported for 1, 2 · MeCN, 3, , 7 · 3MeCN, 8 · 3MeCN and 9.     

三(2-苯并咪唑亚甲基)胺合锰的结构和量化计算

合成了三 ( 2 苯并咪唑亚甲基 )胺合锰 (II) (C48H5 0 N1 4 O4Mn2 Cl4) ,采用X射线单晶衍射方法测定了晶体结构 ,并进行了量子化学计算 .晶体属于单斜晶系 ,空间群P2 1 /C ,晶胞参数 :a =1 4 2 38( 7)nm ,b =2 4 80 2 ( 3)nm ,c =1 6 977( 7)nm ,β =92 51( 4)° ,V =5 9893nm3 ,Z =4 用重原子法及傅里叶合成方法解出结构 ,最终R值为 0 0 7 Mn2 处于变形三角双锥配位环境中 .量子化学计算表明配体具有负电荷空穴 ,使其易于与金属离子配位     

Synthesis,structures, and luminescent properties of two cadmium polymers of 4-carboxyl phenoxyacetate and 2-(2-pyridyl)benzimidazole

Two-dimensional complexes of [Cd(cpoa)(o-pbim)] _n (1) and {[Cd₃(cpoa)₃(o-pbim)₂] · 2H₂O} _n (2) (cpoa²⁻ = 4-carboxyphenoxy acetate, o-pbim = 2-(2-pyridyl)benzimidazole) are synthesized under hydrothermal condition. Single crystal X-ray diffraction analysis shows that complex 1 contains a mono-nuclear unit, whereas complex 2 contains a trinuclear unit. The structural difference of 1 and 2 can be attributed to the various coordination modes of asymmetrically semi-flexible cpoa²⁻ ligand. The luminescent properties of these two compounds are also investigated.     

Crystal structures,selective fluorescent sensing and photocatalytic properties of cobalt(II) and copper(II) coordination architectures with 2,4,5-tri(4-pyridyl)-imidazole

Abstract

Solvothermal reaction of M^II (M?=?Co, Cu) ions with 2,4,5-tri(4-pyridyl)-imidazole (Htpim) gave two MOFs, [Co_1.5(tpim)(FA)₂(H₂O)]_n (1) and [Cu₂(Htpim)(tpim)(FA)(NO₃)₂(DMF)]_n (2) (HFA?=?formic acid, DMF?=?N,N-dimethylformamide). Single-crystal X-ray diffraction analyses indicated that 1 exhibits a 3D {4³.4¹²} topology framework assembled by hexanuclear [Co₆(FA)₈(H₂O)₄] units and tpim ligands, while 2 presents a 2-D double layer {4.6²}₂{4².6⁴.8².10²}{6².8} network. Hereinto, an inorganic acid was not only used to adjust the pH value of reaction system but also to act as an oxidizing agent to participate in in situ organic reactions. Moreover, 1 displays high sensitivity in the detection of nitrobenzene as a fluorescent sensor and exhibits a relatively good photocatalytic activity toward the degradation of rhodamine B in aqueous solution under UV irradiation.     

Syntheses,characterization and luminescent properties of two lead(II) fumarate metal-organic frameworks

It is of interest that the hydrous 3D metal-organic framework (MOF) {[Pb₂(fum)₂(H₂O)₄] · 2H₂O}_n (1) has been synthesized by the reaction of the fum dianion with the lead(II) ion (fum = fumarate) in the presence of pyrazole, while the anhydrous 3D MOF [Pb(fum)]_n (2) is obtained by the reaction of the fum dianion with the lead(II) ion in the presence of pyrazine. These complexes were further characterized by FT-IR spectroscopy, thermogravimetric analysis (TG), X-ray analysis and solid state photoluminescence spectra. The arrangement of the ligands displays a coordination gap around the Pb atom, occupied possibly by a stereoactive lone pair of electrons on lead(II), with the coordination around both the eight-coordinated lead atom in 1 and six-coordinated lead atom in 2 exhibiting a hemidirected geometry. The fum ligand shows different ligation behavior toward the lead(II) ions in these complexes. These compounds exhibit photoluminescence with the maximum emission located in the UV region.     

Synthesis,structures, and fluorescence of two cadmium(II) coordination polymers with a semirigid bis-benzimidazole

Compounds [CdLCl₂] _n (1) and {[Cd(L)₂(ClO₄)]·ClO₄} _n (2), where L?=?1,3-bis(5,6-dimethylbenzimidazol-1-ylmethyl)benzene, have been synthesized by hydrothermal method, and characterized by element analysis, IR spectra, Powder XRD, and X-ray crystallographic diffraction. Cd(II) in 1 and 2 are both trigonal bipyramidal. Different cadmium salts of chloride and perchlorate lead to different configurations of [Cd₂L₂]²⁺, trans-form in 1 but trans and cis-forms in 2. The 1-D beaded chains of 1 are further linked to generate a 3-D supramolecular architecture by strong π–π stacking interactions as well as intermolecular C–H?···?Cl hydrogen bonds. In 2, the 1-D beaded chains are further assembled by intermolecular C–H?···?O hydrogen bonds to form a 2-D layer. Solid-state fluorescent properties of 1 and 2 were investigated at room temperature.     

Syntheses,structures, and photoluminescence of three cadmium(II) coordination polymers with flexible bis(benzimidazole) ligands

Three cadmium(II) coordination polymers, [CdBr₂(L₁)] _n (1), [CdI₂(L₂)] _n (2), and Cd₂Br₄(L₃)₂ (3), where L₁?=?1,3-bis(5,6-dimethylbenzimidazole)propane, L₂?=?1,4-bis(5,6-dimethylbenzimidazole)butane, and L₃?=?1,6-bis(5,6-dimethylbenzimidazole)hexane, have been synthesized by hydrothermal methods and characterized by elemental analyses, IR spectra, TGA, PXRD, and X-ray crystallographic diffraction. Complex 1 contains a 1-D helical chain in which CdBr₂ units are linked by L₁. For 2, each CdI₂ is connected by two different conformations of L₂ to form a 1-D zigzag chain. For 3, each CdBr₂ is linked by L₃ bridges to afford a binuclear structure. These results indicate that the spacer length of the ligands play important roles in assembly of Cd(II) coordination polymers. Thermogravimetric analyses and solid-state luminescent properties of the complexes have also been investigated.     

Syntheses,X-ray structures and properties of a dinuclear cadmium(II)azido and a polymeric cadmium(II)thiocyanato compounds containing bis(tridentate) congregators

One-pot reactions of cadmium(II) perchlorate/nitrate, Schiff bases (pbap/pfap) and pseudohalides (sodium azide/ammonium thiocyanate) in a 2:1:4 molar ratio in MeOH–MeCN solvent mixtures at room temperature result in a dinuclear compound [Cd₂(pbap)(OH₂)₂(N₃)₄] (1) [pbap = N-(1-pyridin-2-ylbenzylidene)-N-[2-(4-{2-[(1-pyridin-2-ylbenzylidene)amino]ethyl}piperazin-1-yl)ethyl]amine] and a polymeric compound [Cd₂(pfap)(μ_1,3-NCS)(μ_1,3-SCN)(NCS)₂]_n (2) [pfap = N-(1-pyridin-2-ylformylidene)-N-[2-(4-{2-[(1-pyridin-2ylformylidene)amino]ethyl}piperazin-1-yl)ethyl]-amine]. X-ray crystal structural analyses reveal a bis(tridentate) congregation behaviour of the hexadentate blocker (pbap/pfap) encapsulating two metal centers. Each cadmium(II) center in 1 and 2 is in a distorted octahedral geometry with CdN₅O and CdN₅S chromophores, respectively. In 1, the dinuclear units participate in intermolecular O–H?N hydrogen bonding between bound water O atoms and terminal azide N atoms, in combination with C–H?π interactions, resulting in a 3D supramolecular network with an intramolecular Cd?Cd distance of 6.473(2) Å. In the crystal lattice, the covalent 1D chain of 2 is further engaged in face-to-face π?π interactions from two terminal pyridine rings, which stabilizes the chain with an intradimer Cd?Cd separation of 6.640(5) Å. Both the complexes display intraligand ¹(π–π^∗) fluorescence and intraligand ³(π–π^∗) phosphorescence in glassy solutions.