The construction of two lanthanide coordination polymers based on 5-hydroxyisophthalate and bipyridine

Two lanthanide coordination polymers, [Tm₂·(5-IPA)₄·(2,2′-Hbipy)₂]·3H₂O (1, 5-H₂IPA?=?5-hydroxyisophthalic acid, 2,2′-bipy?=?2,2′-bipyridine) and [Er·(5-HIPA)₃·(4,4′-bipy)₃·(H₂O)₂]·3H₂O (2, 4,4′-bipy?=?4,4′-bipyridine), have formed by hydrothermal synthesis. Complex 1 exhibits a 2-D coordination network containing parallelepiped-shaped voids occupied by guest 2′2-bipy molecules. Complex 2 possesses a 1-D linear chain structure. The 1-D chains are linked by 4,4′-bipy molecules to form a 3-D supramolecular framework. IR spectroscopy, elemental analysis, and thermogravimetric analysis were also investigated.     

Synthesis,crystal structure,and fluorescence of a 2-D coordination polymer

A 2-D coordination polymer with mixed ligands, [Zn₂(BDC)(4,4′-bipy) (HCOO)₂] (1) (BDC, 1,4-benzenedicarboxylate; 4,4′-bipy, 4,4′-bipyridine), has been synthesized by solvothermal reaction. Compound 1 provides the first coordination polymer structure constructed by bridging BDC, 4,4′-bipy, and formate. Both BDC and 4,4′-bipy link zincs alternatively, resulting in a zigzag coordination chain; adjacent chains are further linked by formates to form an infinite extended 2-D folding screen layer. The synthesis mechanism and fluorescence property are discussed.     

Syntheses,structures, and fluorescent properties of two uranium coordination polymers with carboxylic acids

Two U(VI)-containing coordination polymers, (UO₂)₂O₂(Suc)(2,2′-bipy)₂ (1) and UO₂(BC)₂(DMF) (2) (2,2′-bipy?=?2,2′-bipyridine, H₂Suc?=?succinic acid, HBC?=?benzoic acid, DMF?=?N,N-dimethylformamide), have been synthesized and characterized via elemental analysis, infrared spectroscopy, UV-Vis spectroscopy, and single-crystal X-ray diffraction. Structural analyses show that 1 is a 1-D chain coordination polymer in which U(VI) ions are connected by succinic acid ligand and the 1-D chain is connected into a 3-D supramolecular network by C?H···O hydrogen bonds between carbon of 2,2′-bipyridine and uranyl oxygen. For 2, monomeric entities are further assembled into a 1-D supramolecular network by C–H···O hydrogen bonds between carbon of DMF molecule and coordinated carboxylate oxygen. Thermogravimetric analyses and photoluminescent properties of 1 and 2 are discussed.     

Synthesis and characterization of Pb(II) compounds constructed from N-tosyl-L-glutamic acid

{[Pb(tsgluo)]?·?H₂O} _n (1), [Pb₂(tsgluo)₂(phen)₂] (2), and [Pb₂(tsgluo)₂(bipy)₂] (3) (H₂tsgluo?=?N-p-tolylsulfonyl-L-glutamate, phen?=?1,10-phenanthroline, bipy?=?2,2′-pyridine) have been synthesized in the absence or presence of phen or 2,2′-bipy and structurally characterized by elemental analysis, IR, and X-ray crystallography. Single-crystal X-ray analyses reveal that tsgluo exhibits two coordination modes to link lead ions. Complex 1 gives a 2-D layer structure while 2 and 3 exhibit monomolecular structures; 3 is further connected into a double-chain structure by hydrogen bonds. Phen and 2,2′-bipy are very important for the crystal structure. Fluorescence of the compounds is also discussed.     

Hydrothermal syntheses and structural characterization of two organic–inorganic hybrid compounds based on Lindqvist polyanions

Two organic–inorganic hybrid polyoxometalates {[V₂W₄O₁₉{Cu(2,2′-bipy)₂}₂] · (4,4′-bipy)} _n (1) and [Co(2,2′-bipy)₃][W₆O₁₉] · H₂O (2) (2,2′-bipy = 2,2′-bipyridine, 4,4′-bipy = 4,4′-bipyridine), constructed by Lindqvist polyanions and transition metal coordination cations, have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, UV spectra, thermogravimetric (TG) analyses, X-ray photoelectron spectroscopy (XPS), and single- crystal X-ray diffraction. Compound 1 is a neutral molecule and consists of a di-V^V substituted Lindqvist-type polyanion [V₂W₄O₁₉]^4?, two supporting copper cations [Cu(2,2′-bipy)₂]²⁺ and one free 4,4′-bipy. Neutral molecules of 1 are extended to a 2-D grid-like network by π–π stacking interactions between pyridine groups. The molecular structure of 2 contains one [W₆O₁₉]^2? cluster polyanion and a [Co(2,2′-bipy)₃]²⁺. Inductively coupled plasma (ICP) analysis and XPS spectrum of 1 prove the presence of V^V. TG curves of 1 and 2 indicate two weight loss steps.     

Design,synthesis and magnetic properties of a ladderlike complex constructed by secondary building units

A secondary building unit (SBU), [Ni(2,2′-bipy)(5-npa)(H₂O)] _n [where 2,2′-bipy = 2,2′-bipyridine, 5-npa = 5-nitroisophthalic dianion], was synthesized as starting material of a polystep reaction. A ladderlike complex (LLC) Ni(II) coordination polymer, {[Ni(2,2′-bipy)(5-npa)(4,4′bipy)_0.5]·(H₂O)} _n , was constructed by polystep reaction using this SBU. In LLC, two SBUs were cross-linked by 4,4′-bipy [where 4,4′-bipy = 4,4′-bipyridine] forming a 1-D ladderlike structure. The magnetic properties of the LLC and SBU are discussed.     

A one-dimensional organic–inorganic hybrid constructed by saturated Keggin polyoxoanions and [CuI(4,4′-bipy)] n n + chains

A one-dimensional (1-D) organic–inorganic hybrid compound {(H₃O)[Cu^I(4,4′-bipy)]₃[SiW₁₂O₄₀]} · 1.5H₂O (1) has been synthesized from hydrothermal reaction of Keggin polyoxometalate, cupric nitrate and 4,4′-bipyridine (4,4′-bipy). Single crystal X-ray diffraction shows 1-D zigzag chains built up of saturated Keggin polyoxoanions and infinite [Cu^I(4,4′-bipy)] _n ^{n +} units. Zipper-like arrangement of adjacent zigzag chains by hydrogen-bonding interactions leads to a 2-D layer and π–π interactions of 4,4′-bipy ligands from adjacent layers further result in the 3-D structure of 1. All Cu atoms in 1 are three-coordinated with “T-type” geometries, indicating they are univalent in the resultant compound. This result has further been confirmed by the absence of signal in the EPR spectrum of 1.     

Supramolecular structures of CdX2-containing coordination compounds constructed by C–H ··· X synthons

Three CdX₂-containing (X = Cl, Br) compounds [CdBr₂(Him)₂] _n (Him = imidazole) (1), [CdCl₂(2,2′-bipy)] _n (2,2′-bipy = 2,2′-bipyridine) (2), and [CdCl₂(phen)] (phen = phenanthroline) (3) have been synthesized through hydrothermal technique. Compound 1 adopts 1-D coordination chain, which is connected to form a 3-D supramolecular network by inter-chain N–H ··· Br and C–H ··· Br hydrogen bonds. Compound 2 also adopts 1-D coordination chain, which is connected to form 3-D supramolecular network by intra- and inter-chain C–H ··· Cl hydrogen bonds; 3 is discrete, linked to form 2-D supramolecular sheets by intra- and inter-molecular C–H ··· Cl hydrogen bonds. The different volume and coordination ability of organic ligands result in the different coordination structure and supramolecular synthons. All these compounds exhibit strong fluorescence emissions at room temperature.     

Hydrothermal Synthesis,Conversion Reaction,and Crystal Structure of 2-D 2-bromo-1,4-benzenedicarboxylate Copper(II) Complex with 2,2′-bipyridine

A fully deprotonated 2-bromo-1,4-benzenedicarboxylate copper(II) complex, [Cu(bbdc)(2,2′-bipy)](H₂O) (bbdc= 2-bromo-1,4-benzenedicarboxylate dianion, 2,2′-bipy=2,2′-bipyridine), was synthesized under hydrothermal conditions. This compound also can be prepared from the partly deprotonated [Cu(Hbbdc)₂(2,2′-bipy)] under basic and hydrothermal conditions. The crystal structure consists of infinite chains of [Cu₂(μ₄-bbdc)]²⁺ building blocks connected by bis-monodentate bbdc ligands and exhibits an extended 2-D architecture. Electronic supplementary material Electronic supplementary material is available for this article at and accessible for authorised users.     

Synthesis,characterization, and cytotoxicity of mixed-ligand complexes of platinum(II) with 2,2′-bipyridine and 4-toluenesulfonyl-L-amino acid dianion

Five new platinum(II) complexes (1–5) with 4-toluenesulfonyl-L-amino acid dianion and 2,2′-bipyridine (bipy) have been synthesized and characterized by elemental analysis, IR, UV, ¹H-NMR, ¹³C-NMR, and mass spectra. The crystal structure of 1 has been determined by X-ray diffraction analysis. Cytotoxicity was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and sulforhodamine B (SRB) assays. The results indicate that 1–5 exert cytotoxic effects with selectivity against tested carcinoma cell lines; 5 displays better cytotoxicity against BGC-823, Bel-7402, and KB cell lines, while 1 has better cytotoxicity against KB cell line. The 4-toluenesulfonyl- L-amino acid dianions have important effects on cytotoxicity; when 4-toluenesulfonyl-L-amino acid dianions are 4-toluenesulfonyl-L-glycine and 4-toluenesulfonyl-L-phenylalanine, the complexes show better cytotoxicity.     

Syntheses and characterizations of zinc(II) and copper(II) complexes with reduced Schiff base derived from salicylaldehyde and D,L-selenomethionine

New zinc(II) and copper(II) complexes with a reduced Schiff-base ligand derived from D,L-selenomethionine and salicylaldehyde have been synthesized and characterized by elemental analysis, magnetic susceptibility, IR, and NMR measurements. The single-crystal X-ray structure of the Cu(II) complex reveals that this complex is a carboxylate-bridged dimer of dinuclear copper(II) subunits and all metal centers are five-coordinate with O₄N donor sets in distorted square-pyramidal geometries. The Cu(II) complex consists of a 1-D coordination polymer.     

Synthesis,structure, and character of two rare earth carboxylic acid complexes

Two rare earth carboxylic acid complexes, [Sm(MeBA)₃(2,2′-bipy)]₂·2(2,2′-bipy) (MeBA = 3-methylbenzoic acid; 2,2′-bipy = 2,2′-bipyridine) (1) and [Pr(MeBA)₃(H₂O)₂]_n?n(4,4′-bipy) (4,4′-bipy = 4,4′-bipyridine) (2), have been synthesized under hydrothermal conditions and structurally determined by single-crystal X-ray diffraction. Compound 1 is a dimer and further assembles into an infinite chain, two-dimensional net and three-dimensional supramolecular structure via weak π–π and C–H···π interactions. Some 2,2′-bipy coordinates with Sm and some exist by non-covalent C–H···π interactions. Compound 2 is a 1D infinite chain structure, with adjacent 1D chains connected into a 2D layer structure by O–H···N hydrogen bonds. The two complexes were characterized by elemental analyses, IR, photoluminescence, and TGA. In order to illustrate subtle structural characteristics of intermolecular interactions and magnetic sensitivity of the complex, 2D-IR correlation spectra (2D-IR COS) under magnetic perturbation for 1 were performed.     

Syntheses,structures, and properties of two new hybrid Dawson-based polyoxotungstates [Mn(2,2′-bipy)3]H2 [Mn(2,2′-bipy)2][P2W18O62] and [Co(H2biim)3)]2H2[P2W18O62] · 8H2O

Two new hybrid Dawson-based polyoxotungstates, [Mn(2,2′-bipy)₃]H₂[Mn(2,2′-bipy)₂][P₂W₁₈O₆₂] (1) and [Co(H₂biim)₃)]₂H₂[P₂W₁₈O₆₂] · 8H₂O (2) (2,2′-bipy = 2,2′-bipyridine, H₂biim = 2,2′-biimdazole), have been prepared under hydrothermal conditions and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra, thermogravimetric analyses (TGA), X-ray photoelectron spectroscopy (XPS), and photoluminescence spectra. Compound 1 is a 1-D zigzag chain constructed from alternate Dawson-type heteropolyanions [α-P₂W₁₈O₆₂]^6? and metal coordination cations [Mn(2,2′-bipy)₂]²⁺, in which the 1-D chains are extended into a 3-D framework through C–H ··· π and π–π stacking interactions. Compound 2 is a discrete structure consisting of [α-P₂W₁₈O₆₂]^6? and two [Co(H₂biim)₃)]²⁺ cations, forming a 3-D supramolecular framework via N–H ··· O hydrogen bonds and C–H ··· π interactions. Photoluminescence properties of 1 and 2 have been investigated at room temperature.     

The Cu-catalyzed asymmetric conjugate addition with chiral diphosphite ligands derived from D-(-)-tartaric acid

A series of diphosphite ligands, which were derived from D-(-)-tartaric acid, have been synthesized and successfully applied in the Cu-catalyzed asymmetric conjugate addition of organozincs to enones. There was a synergic effect between the stereogenic centers of the D-(-)-tartaric acid skeleton and the axially H₈-binaphthyl moieties of ligand 2c. And ligand 2c shows a comparative catalytic performance to ligand 1-N-benzylpyrrolidine-3,4-bis[(S)-1,1′-H₈-binaphthyl-2,2′-diyl]phosphite-L-tartaric acid1d derived from L-(+)-tartaric acid. Therefore, for cyclic enones, both enantiomers of the addition products can be obtained in high enantioselectivity (ees up to 96%) by simply selecting ligands 1d or 2c derived from D-(-)-tartaric acid or L-(+)-tartaric acid. Moreover, the sense of enantiodiscrimination of the products was mainly determined by the configuration of the binaphthyl phosphite moieties.     

Stereospecific interactions through π -conjugated systems of sulfur-bridged dinuclear Co(III)-Pd(II) and Co(III)-Pt(II) complexes of optically active penicillaminates

The reaction of trans(N)-[Co(D-pen)₂]^? (pen = penicillaminate) or trans(N)-[Co(L-pen)₂]^? with [MCl₂(L)] (M = Pd or Pt, L = 2,2′-bipyridine (bpy) or 4,4′-dimethyl-2,2′-bipyridine (dmbpy)) stereoselectively gave an optically active S-bridged dinuclear complex, [M(L){Co(D-pen)₂}]Cl · 3H₂O or [M(L){Co(L-pen)₂}]Cl · 3H₂O. The mixture of equimolar amounts of these two enantiomers in H₂O crystallizes as [M(L){Co(D-pen)₂}]_0.5[M(L){Co(L- pen)₂}]_0.5Cl · nH₂O (1cCl · 7H₂O: M = Pd, L = bpy, n = 7; 2cCl · 7H₂O: M = Pd, L = dmbpy, n = 7; 3cCl · 6H₂O: M = Pt, L = dmbpy, n = 6), in which the enantiomeric complex cations are included in the ratio of 1 : 1. In the crystals of 1cCl · 7H₂O, [Pd(bpy){Co(D-pen)₂}]⁺ (1a) and [Pd(bpy){Co(L-pen)₂}]⁺ (1b) are arranged alternately while overlapping the bpy planes along the a axis, and the π electronic systems of bpy moieties interact with each other. This is quite a contrast to the optically active 1aCl · 3H₂O or 1bCl · 3H₂O, which exist as monomers without intermolecular interactions. In crystals of 2cCl · 7H₂O and 3cCl · 6H₂O, similarly, the two enantiomeric complex cations interact with each other through the dmbpy frameworks. However, the interplane distances between the stacked π systems in these dmbpy complexes are considerably longer than in the bpy complexes. Such structural characteristics significantly reflect their diffuse reflectance spectra.     

Syntheses,structures, thermal stabilities and bacteriostatic activities of four lanthanide complexes

Four lanthanide complexes, [La₂(2,4-DClBA)₆(5,5′-DM-2,2′-bipy)₂(H₂O)₂]·2C₂H₅OH (1) and [Ln(2,4-DClBA)₃(5,5′-DM-2,2′-bipy)(C₂H₅OH)]₂ (Ln = Pr(2), Sm(3), Gd(4); 2,4-DClBA = 2,4-dichlorobenzoate; 5,5′-DM-2,2′-bipy = 5,5′-dimethyl-2,2′-bipyridine), were synthesized and characterized via elemental analysis, infrared spectra and thermogravimetric analysis (TG). The crystal structures of 1 and 2–4 are different; Each La³⁺ is nine-coordinate adopting a distorted mono-capped square antiprism, while the Ln³⁺ ions of 2–4 are all eight-coordinate with a distorted square antiprismatic molecular geometry. There are subtle changes in the local coordination geometry of the lanthanide–5,5′-DM-2,2′-bipy complexes. Binuclear 1 complexes are stitched together via two kinds of hydrogen bonding interactions (OH?O and CH?O) to form 1-D chains along the y axis, while the units of 2–4 are stitched together via CH?O to form 1-D chains along the x axis. TG analysis revealed thermal decomposition processes and thermal stabilities of the complexes. The bacteriostatic activities of the complexes were evaluated against Candida albicans, Escherichia coli, and Staphylococcus aureus.     

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.     

Copper(I) and copper(II) complexes with pyrazine-containing pyridylalkylamide ligands N-(pyridin-2-ylmethyl)pyrazine-2-carboxamide and N-(2-(pyridin-2-yl)ethyl)pyrazine-2-carboxamide

Four copper(II) complexes and one copper(I) complex with pyridine-containing pyridylalkylamide ligands N-(pyridin-2-ylmethyl)pyrazine-2-carboxamide (HL^pz) and N-(2-(pyridin-2-yl)ethyl)pyrazine-2-carboxamide (HL^pz?) were synthesized and characterized. The X-ray crystal structures of [Cu₂(L^pz)₂(4,4?-bipy)(OTf)₂] (1, OTf?=?trifluoromethanesulfonate, 4,4?-bipy?=?4,4?-bipyridine) and [Cu(L^pz)(py)₂]OTf·H₂O (2, py?=?pyridine) revealed binuclear and mononuclear molecular species, respectively, while [Cu(L^pz)(μ₂-1,1-N₃)]_n (3), [Cu(L^pz?)(μ₂-1,3-N₃)]_n (4), and [Cu(HL^pz)Cl]_n (5) are coordination polymer 1-D chains in the solid state.     

Synthesis,structural characterization,and photocatalytic study of transition metal coordination polymers constructed from mixed ligands

Three 3-D coordination polymers, [Cu(cca)(4,4′-bipy)]_n (1), [Co₃(pda)₃(1,10′-phen)₂]_n (2), and [Co(pda)(1,10′-phen)]_n (3), have been synthesized from 4-carboxycinnamic acid (cca), 1,4′-phenylenediacrylic acid (pda), 4,4′-bipyridine (4,4′-bipy), 1,10′-phenanthroline (1,10′-phen), and Cu and Co salts under different conditions. The X-ray crystal structures of these three complexes are presented. Complex 1 exhibits a threefold 3-D α-Po interpenetration network. Complex 2 with a 3-D framework with six-connected single α-Po framework constructed from Co₃ unit has been synthesized and characterized. Complex 3 shows a 3-D framework with bcu topology composed of 1-D rod-shaped secondary building units. Furthermore, the photocatalytic properties of 2 were studied. When excited by UV light, 2 exhibits photocatalytic activity, in 300?min, about 71% Rhodamine B decomposes.     

Syntheses,crystal structures and antibacterial activities of M(II) benzene-1,2,3-triyltris(oxy)triacetic acid complexes

Four metal(II) complexes with benzene-1,2,3-triyltris(oxy)triacetic acid (H₃L), {[Co_1.5(L)(H₂O)₆]·6H₂O}_n (1), {[Co_1.5(L)(4,4′-bipy)_1.5(H₂O)₄]·4H₂O}_n (2), {[Co(HL)(2,2′-bipy)(H₂O)₂]·1.5H₂O}_n (3), and {[Cu(HL)(phen)(H₂O)₂]·H₂O}_n (4) (4,4′-bipy = 4,4′-bipyridine; 2,2′-bipy = 2,2′-bipyridine; phen = phenanthroline), were prepared and structurally characterized. Complex 2 displays a 1-D structure, while 1, 3, and 4 reveal 0-D structures, which further extend to 3-D supramolecular networks by hydrogen bonding interactions, of which 1 and 4 contain double-helical chains, 2 includes meso-helices, and 3 comprises single-helices. Furthermore, the thermal stabilities and antibacterial activities of the complexes were studied.