Halide anions driven self-assembly of haloperfluoroarenes: Formation of one-dimensional non-covalent copolymers

The supramolecular organization in six solid assemblies involving iodo- and bromoperfluoroarene derivatives is described. Single crystal X-ray analyses show that the formation of the supramolecular architectures is controlled by I⁻?Br–Ar_F, I⁻?I–Ar_F, Br⁻?I–Ar_F, and Cl⁻?I–Ar_F halogen bondings thus proving the X⁻?X′–Ar_F supramolecular synthon, where X can be the same as or different from X′, is particularly robust. In five of the described architectures halide anions form two halogen bondings and form infinite chains wherein dihaloperfluoroarenes, which function as bidentate electron acceptors, and halide anions, which function as bidentate electron donors, alternate. This behaviour shows halide anions have a fair tendency to work as bidentate halogen bonding acceptors.     

Square-planar nickel(II) complexes with a tridentate Schiff base and monodentate heterocycles: self-assembly to dimeric and one-dimensional array via hydrogen bonding

Square-planar nickel(II) complex with tridentate ONO-donor 4-[(2-hydroxyphenyl)imino]-2-pentanone (H₂hpac) and imidazole (Himdz) are reported. The complex was synthesized in moderate yield by reacting Ni(O₂CCH₃)₂ · 4H₂O, H₂hpac and imidazole in 1 : 1 : 1 mole ratio and characterized by elemental analysis, IR, ¹H NMR spectroscopy. An X-ray structure determination of the complex has been completed. In the solid state, a one-dimensional assembly of the [Ni(hpac)(Himdz)] molecules is formed via intermolecular hydrogen bonds between the imidazole N–H groups and the coordinated hydroxyphenyl-O atoms.     

Novel Heterometallic Polymers Induced by Host-Guest Cations: X-ray Structures of [(18-crown-6)KAgWS4]n and [{ (18-crown-6)Ba(DMF)4}(Ag2W2S8)]n

Abstract

α-Keto acids have characteristic unpleasant smell and chemical instability, which makes the usages of the materials difficult for pharmaceutical purposes. However, the inclusion compounds of the acids with cyclodextrins have no or slight smell and are chemically stable. Especially, an inclusion compound of optically active s-α-keto-β-methylvaleric acids (S-KMV) kept its activity for at least 120 days at room temperature, unlike its salt of basic amino acid. We tried to investigate the solid state structure of the inclusion compounds S-KMV / β-CD by the use of CPMAS ¹³C NMR spectroscopy. The comparison of the spectra of S-KMV / β-CD and KMV·1/2Ca·H₂O suggested that the S-KMV molecule is not so tightly included inside the β-CD cavity, but as a result of rotational isomerism restriction, it exists in a single conformer.     

Self-assembly syntheses and crystal structures of triorganotin(IV) pyridinecarboxylate: 1D polymers and a 42-membered macrocycle

A series of new triorganotin(IV) pyridinecarboxylates with 6-hydroxynicotinic acid (6-OH-3-nicH), 5-hydroxynicotinic acid (5-OH-3-nicH) and 2-hydroxyisonicotinic acid (2-OH-4-isonicH) of the types: [R₃Sn (6-OH-3-nic)·L]_n (I) (R = Ph, L = Ph·EtOH, 1; R = Bn, L = H₂O·EtOH, 2; R = Me, L = 0, 3; R = n-Bu, L = 0, 4), [R₃Sn (5-OH-3-nic)]_n (II) (R = Ph, 5; R = Bn, 6; R = Me, 7; R = n-Bu, 8), [R₃Sn (2-OH-4-isonic·L)]_n (III) (R = Bn, 9, L = MeOH; R = Me, L = 0, 10; R = Ph, 11, L = 0.5EtOH) have been synthesized. All the complexes were characterized by elemental analysis, TGA, IR and NMR (¹H, ¹³C, ¹¹⁹Sn) spectroscopy analyses. Among them, except for complexes 5 and 6, all complexes were also characterized by X-ray crystallography diffraction analysis. Crystal structures show that complexes 1-10 adopt 1D infinite chain structures which are generated by the bidentate O, O or N, O and the five-coordinated tin centers. Significant O-H?O, and N-H?O intermolecular hydrogen bonds stabilize these structures. Complex 11 is a 42-membered macrocycle containing six tin atoms, and forms a 2D network by intermolecular N-H?O hydrogen.     

Coexistence of two halide hydrate clusters in a crystal of 1,1′-(benzene-1,3-diyldimethanediyl)-bis(3,5,7-triaza-1-azoniatricyclo[3.3.1.13,7]decane) dibromide trihydrate. X-ray structure,Hirshfeld surface and thermal analysis

The title compound, C₂₀H₃₂N₈²⁺·2Br⁻·3H₂O, was obtained by the reaction of 1,3,5,7-triazatricyclo[3.3.1.1^3,7]decane with 1,3-bis(bromomethyl)benzene in acetonitrile. The asymmetric unit contains a unique 1,1′-(benzene-1,3-diyldimethanediyl)bis(3,5,7-triaza-1-azoniatricyclo[3.3.1.1^3,7]decane)dication, two bromide anions and three water molecules. The 3,5,7-triaza-1-azoniatricyclo[3.3.1.1^3,7]decane (C₆N₄H₁₂)⁺ moieties lie on the same side of the molecule, and the pseudo torsion angle (H₁₂N₄C₆)CH₂⋯CH₂(C₆N₄H₁₂) is −5.25 (18)°. The molecular dication C₂₀H₃₂N₈⁺ is charge-balanced by a pair of crystallographically independent halide hydrate clusters, and the cation and clusters are interlinked by CH⋯O and CH⋯Br hydrogen bonds. The Hirshfeld surface analysis and fingerprint plots reveal that the packing in compound 2 is directed mainly by H⋯H (56.7%) and H⋯Br/Br⋯H (21.3%) contacts. The thermal analysis showed between 30 and 180 °C the gradual loss of three water molecules, which represents the loss of one and two crystalline water molecules from the two types of clusters, respectively. A second noticeable weight loss between 180 and 230 °C is observed, depictive of the thermal decomposition of the dication of the title compound.     

Crystal structure of tetraethylammonium fluoride-water (4/11), 4(C2H5)4N+F− · 11H2O,a clathrate hydrate containing linear chains of edge-sharing (H2O)4F− tetrahedra and bridging water molecules

Crystals of 4(C₂H₅)₄N⁺F^– · 11H₂O are orthorhombic, space groupPna2₁, witha=16.130(3),b=16.949(7),c=17.493(7) Å, andZ=4. The structure was shown to be a clathrate hydrate containing infinite chains of edge-sharing (H₂O)₄F^– tetrahedra extending parallel to thea axis. The chains are laterally linked by bridging water molecules to form a three-dimensional hydrogen-bonded anion/water framework. The ordered (C₂H₅)₄N⁺ cations occupy the voids in two open channel systems running in theb andc directions. FinalR _F =0.091 for 2278 observed MoK data measured at 22°C. Supplementary Data: relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82010 (20 pages).Dedicated to Professor H. M. Powell.     

Synthesis and Characterization of the 1 : 1-Adducts of In(C6F5)3 with Acetonitrile,Glyme, and DMAP (DMAP = 4-(N,N-dimethylamino)pyridine), and [PNP][In(C6F5)4] (PNP = bis(triphenylphosphinanyliden)immonium) – the Crystal Structure of [PNP][In(C6F5)4]

In(C₆F₅)₃ · CH₃CN and In(C₆F₅)₃ · glyme were synthesized from InCl₃ and Cd(C₆F₅)₂ in CH₃CN or glyme in 43% and 35% yield, respectively. Replacement of CH₃CN or (C₂H₅)₂O by DMAP yielded the corresponding 1 : 1-adduct. [PNP][In(C₆F₅)₄] was best prepared from the corresponding cesium salt which was best synthesized from the reaction of stoichiometric amounts of In(C₆F₅)₃ · CH₃CN, (CH₃)₃ SiC₆F₅ and CsF in good yield. [PNP][In(C₆F₅)₄] crystallizes in the triclinic space group P 1, a = 1104.9(4) pm, b = 1442.4(6) pm, c = 1833.8(8) pm, α = 110.87(2)°, β = 92.04(3)°, γ = 96.55(3)°, Z = 2.     

Crystal structure and characterization of two cadmium(II) coordination polymers with a multidentate N-donor tecton 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole

Two new cadmium(II) complexes [Cd_1.5(L)Cl₂(H₂O)]_{2 n} (1) and [CdL₂] _n (2) with a multidentate N-donor building block 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole (HL) have been prepared and characterized by elemental analysis, infra-red spectra, powder X-ray diffraction (XRD), and single-crystal XRD. 1 is a 2-D layered coordination polymer constructed from linkage of [Cd₃(μ-Cl)₄] trinuclear units with HL spacers, while 2 shows a 2-D layer structure. 3-D supramolecular architectures are further assembled in 1 and 2 via hydrogen-bonding contacts. Both 1 and 2 are thermally stable to 450?°C, and 2 showed strong fluorescent emission bands.     

Chains,helices, sheets and unusual 3D nets: Diverse structures of the flexible,ditopic ligand 1,2-bis(3-(4-pyridyl)pyrazolyl)ethane

The flexible ditopic ligand 1,2-bis(3-(4-pyridyl)pyrazol-1-yl)ethane (L^4Et) displays remarkable versatility in the complexes that it forms with transition metals with products ranging from 1D chains to interpenetrating 3D networks. The L^4Et ligand itself crystallises in the space group P2₁, adopting a helical twist, although it is found in a variety of other conformations in its complexes. Coordination polymers containing the L^4Et ligand vary from almost straight, parallel 1D chains of [Ag₂(L^4Et)₂(ClO₄)₂(DMF)]·DMF (1), through interdigitating helical complexes containing tetrahedral Zn(II), [Zn(NCS)₂(L^4Et)]·DMF·H₂O (2) to 2D sheets of [Cu(L^4Et)₂(H₂O)₂](PF₆)₂·xH₂O (3) and the three-fold interpenetrating 3D network of [Co(L^4Et)₂(NCS)₂] (4). The 3D network adopts an unusual 3D 4-connected dmp (6⁵.8) topology. Dimensionality can be limited by the use of chelating co-ligands, demonstrated by the formation of the dinuclear complex [{Cu(py-2,6-CO₂)(H₂O)}₂(L^4Et)] (5).     

Bis(2-(1H-imidazol-2-yl)-pyridine)copper(II): Effects of counteranions on the molecular and supramolecular structures

The synthesis and physical properties of bis(2-(1H-imidazol-2-yl)-pyridine)copper(II) with chloride, nitrate and perchlorate as counteranions have been described. Microanalysis, magnetic susceptibility, conductivity and various spectroscopic measurements have been used for the characterization of the complexes. The crystal structures of all three complexes have been determined. Intermolecular hydrogen-bonding interactions and the resulting self-assembly patterns for each of the species have been scrutinized. The chloride containing complex crystallizes as a trihydrate, where the metal ion is in a tetragonally elongated cis-N₄Cl₂ coordination sphere. This complex provides a three-dimensional honeycomb-like structure through N–H?Cl, O–H?Cl and O–H?O hydrogen bonds. In the nitrate containing species, one of the two counteranions coordinates to the metal centre to provide an irregular N₄O₂ coordination sphere, while the other counteranion, with the help of a lattice water molecule, assembles a ladder-like structure via N–H?O and bifurcated O–H?O,O hydrogen bonds. A one-dimensional polymeric species has been formed when perchlorate is the counteranion. Here one of the two perchlorates acts as a bridge between the metal centres that are in tetragonally elongated trans-N₄O₂ coordination spheres. This polymeric chain, together with the second perchlorate and a water molecule, form a ribbon-like structure due to N–H?O and O–H?O hydrogen bonds.     

Supramolecular networks of Mn(III)-Schiff base complexes assembled by nitrate counterions: X-ray crystal structures of 1D chains and 2D networks

A series of Mn(III) nitrate complexes have been synthesized from dianionic hexadentate Schiff bases obtained by condensation of 3-methoxy-2-hydroxybenzaldehyde with different diamines. The complexes have been characterised by elemental analysis, ESI mass spectrometry, IR and ¹H NMR spectroscopy. Magnetic studies and molar conductivity measurements were also performed. Complexes [MnL¹(H₂O)₂]₂·2NO₃·2CH₃OH (1), [MnL²(H₂O)₂]₂·2NO₃·2CH₃OH (2) and [MnL⁵(H₂O)₂]₂·2NO₃·6H₂O (5) were crystallographically characterised. The X-ray structures show an octahedral geometry around the metal with the Schiff base in the equatorial plane acting as tetradentate and water or methanol molecules in the axial positions. The octahedron entities are linked in pairs by μ-aquo bridges between neighbouring axial water molecules and also by π-π stacking interactions, establishing dimeric and polymeric structures. Nitrate anions are accommodated in the cavities of the framework and form hydrogen bonds with the aqua ligands and the methanol or crystal water, leading to infinite supramolecular aggregates of the complexes. Comparison of chloride, perchlorate and nitrate complexes indicate that the nature of the anions is the key factor directing the structural topologies.     

Crystal Structure and DFT Studies of a Triazole Derivative： 4- （ 2-Hydrobenzylideneamino ） -3- （ 1,2,4-triazol-4-ylmethyl） 1H-1, 2,4-triazole-5 （4H） -thione

A novel triazole derivative 4-(2-hydrobenzylideneamino)-3-(1,2,4-triazol-4-ylmethyl)-1H-1,2,4-triazole-5(4H)-thione(1) was synthesized and characterized using elemental analysis, FTIR, and 1H NMR, and its crystal structure was determined via X-ray single crystal diffraction analysis. Crystal data: monoclinic, P2(1)/c, a=0.83335(9) nm, b=1.49777(16) nm, c=1.14724(12) nm, β =107.990(2)°, D=1.470 Mg/m3, and Z=4. The geometries and the vibrational frequencies were determined using the density functional theory(DFT) method at the B3LYP/ 6-31G level. To demonstrate the accuracy of the reaction route of compound 1, one of the important intermediates was also tested using the same method. The structural parameters of the two compounds calculated using the DFT study are close to those of the crystals, and the harmonic vibrations of the two compounds computed via the DFT method are in good agreement with those in the observed IR spectral data. The thermodynamic properties of the title compound were calculated, and the compound shows a good structural stability at normal temperature. The test results of biological activities show that it has a certain bactericidal ability.     

Solvothermal Synthesis and Crystal Structure of the New Layered Thioantimonate(III) [Ni(C4H13N3)2]9Sb22S42 · 0.5H2O: Interconnection of the SbS3, SbS4, and SbS5 Primary Building Units Yielding the Very Large Sb30S30 Heteroring

The novel thioantimonate(III) [Ni(dien)₂]₉Sb₂₂S₄₂ · 0.5H₂O was synthesised under solvothermal conditions by reacting elemental Ni, Sb and S in an aqueous solution of diethylenetriamine (dien) (80%). The compound crystallises in the triclinic space group P1¯, a = 8.997(2) Å, b = 15.293(3) Å, c = 34.434(7) Å, α = 85.51(3)°, β = 84.16(3)°, γ = 83.54(3)°, V = 4672.7 (16) ų, Z = 1. The layered [Sb₂₂S₄₂^18—] anion in [Ni(dien)₂]₉Sb₂₂S₄₂ · 0.5H₂O is composed of nine SbS₃ trigonal pyramids, one SbS₄ and one SbS₅ unit. The interconnection of these units by sharing common S atoms yields Sb‐S heterorings of different sizes. Besides the smaller Sb₂S₂ and Sb₃S₃ rings a very large Sb₃₀S₃₀ heteroring is observed. The structure directing effect of the [Ni(dien)₂]²⁺ cations is obvious as they are located above and below the pores of the anion. The nine [Ni(dien)₂]²⁺ cations exhibit different conformations. All Ni²⁺ cations are in an octahedral environment of six N atoms of two dien ligands. The anions and cations are stacked perpendicular to [100] in an alternating fashion.     

Cadmium‐1,3,6,8‐tetrakis(4‐carboxylphenyl)pyrene Framework as a Thermometer for Fluorescence Sensing of Temperature

Compounds exhibiting tunable fluorescence emission upon adjusting the temperature are considered smart materials. Herein a three‐dimensional structure of {[Cd(TBAPy)(H₂O)₂] · 4(H₂O)}_n ( 1 ) constructed from Cd^II and 1,3,6,8‐tetrakis(4‐carboxylphenyl)pyrene (TBAPy^4–) ligand was synthesized and characterized. Temperature‐dependent fluorescence studies showed the emission intensities for compound 1 decrease as temperature increasing. The emission intensity is linearly related to temperature in the range of 100 to 300 K. This findings demonstrate that compound 1 is a good candidate for temperature sensitive sensor over a wide temperature range. Such a fluorescence behavior is closely related to the highly conjugated organic ligand with a pyrene core.     

Conformational effect of 2,6-bis(imidazol-1-yl)pyridine on the self-assembly of 1D coordination chains: spontaneous resolution, supramolecular isomerism, and structural transformation

The achiral 2,6-bis(imidazol-1-yl)pyridine (L) was used as the ditopic organic tecton for the formation of coordination polymers with Zn(II) ions. Hydrothermal reaction between L and ZnX2 (X=Br, Cl) afforded spontaneous resolved double helical motifs in ZnLCl2.0.5H2O (1) and ZnLBr2.0.25H2O (2). In the homochiral crystals of 1a and 2a, the helices are of M-helicity, whereas, in 1b and 2b, they are of P-helicity. In contrast, solvothermal reaction between L and ZnCl2 in dried DMF afforded achiral ZnLCl2 (3a), which exhibits a zigzag polymeric motif. An achiral polymorph 3b which contains 21 helical chains was obtained in wet DMF. The formation of different 1D motifs was related to the conformations of L. All these compounds were characterized by infrared spectroscopy, elemental analyses, and single-crystal X-ray diffraction. As revealed by thermal gravimetric analysis and powder X-ray diffraction study, the homochiral motif in 1 was stable even upon removal of guest water molecules. Contrastingly, structural transformation from 3a or 3b to 1 is possible upon hydration.     

Synthesis and structure of a novel three-dimensional metal selenite containing multidirectional intersecting double helical chains: [Fe2(H2O)4(SeO3)2]

A novel three-dimensional metal selenite [Fe₂(H₂O)₄(SeO₃)₂] (1) has been hydrothermally synthesized and characterized by the elemental analyses, IR spectrum, TG analysis and the single crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic system, space group P21/n, with a=6.5283(13) Å, b=8.8754(18) Å, c=7.6798(15) Å, (=98.82(3)β, V=439.71(15) Å3, and Z=2. Compounds 1 exhibits interesting three-dimensional structure constructed from {FeO₆} octahedra and {SeO₃} pyramids linked via the corner- and/or edge-sharing mode. The most interesting structural feature of compound 1 is that the existence of multidirectional intersecting double helical chains in one compound.     

The Hydrogen-Bonded Framework of the First Anti-Zeotype: [{(H2NEt2)2}2(CuCl4)][AlCl4]

A two-coordinate cationic link between [CuCl₄]³⁻ tetrahedra by means of two inversion-related dialkylammonium cations yields the hydrogen-bonded A₂X anti-cristobalite framework [{(H₂NEt₂)₂}₂(CuCl₄)]⁺. This novel cationic framework is constructed around space-filling and templating [AlCl₄]⁻ anions resulting in large pores (16.6×6.7 Å).     

Novel 1D Cu(I) coordination polymers formed by the combination of Cu(I) halides and 4-(2-pyridyl)pyrimidine

Three novel 1D Cu(I) coordination polymers [Cu₄X₄(pprd)₂]_n (X = Cl(1), Br(2) and I(3); pprd = 4-(2-pyridyl)pyrimidine) were systematically synthesized by Cu(I) halides and the pprd ligand, and they have been characterized by X-ray, IR, and TG-DTA analyses. The molecular structure of complex 1 essentially resembles to that of complex 2. In complexes 1 and 2, four Cu(I) atoms are bridged by four Cl or Br anions to form an eight-membered Cu₄X₄ framework in the twist-chair form. Furthermore, the Cu₄X₄ frameworks are coordinated by the chelate and bridging sites of two pprd ligands to form a unique 1D two-stepped Cu(I) coordination polymer, in which two stairs are formed by the Cu₄X₄ core and two heteroaromatic planes of pprd. In the crystal packing structures, it is interesting that two heteroaromatic planes of pprd are stacking along the b-axis for complex 1 and the a-axis for complex 2. In contrast, four Cu(I) atoms in complex 3 are bridged by four I atoms to form a Cu₄I₄ stepped cubane tetramer. Additionally, the Cu₄I₄ stepped cubane cores are linked by the chelate and bridging sites of two pprd ligands to form an infinite 1D zigzag-chain Cu(I) coordination polymer. The thermal decomposition behaviors for Cu(I)–X/pprd complexes 1, 2 and 3 were determined by thermogravimetric analysis (TG-DTA). Although the thermal decomposition behaviors of complex 1 were unidentified, those of complexes 2 and 3 were assigned. The mass loss at the first stage of thermal decomposition for polymeric [Cu₄X₄(pprd)₂]_n was identical to the formation of oligomeric [Cu₄X₄(pprd)] by the elimination of one pprd molecule. The mass loss at the next stage was decided to the formation of Cu₄X₄ by the elimination of another pprd molecule.     

Mixed-ligand metallosupramolecular complexes with Brn-terephthalic acid (n = 1 or 4) and a versatile bent dipyridyl tecton: Structural modulation by substituent effect of the ligand and metal ion

This work presents a series of Zn^II, Cd^II, Co^II, and Pb^II supramolecular complexes assembled from a bent dipyridyl derivative 2,5-bis(3-pyridyl)-1,3,4-oxadiazole (3-bpo) and different dicarboxyl co-ligands 2-bromoterephthalic acid (H₂BTA) and tetrabromoterephthalic acid (H₂TBTA). All products have been prepared under similar conditions and characterized by IR, microanalysis, and TG–DTA techniques. Single-crystal X-ray diffraction indicates that these complexes display mononuclear, 1-D, and 2-D coordination motifs, and diverse higher-dimensional extended networks are further constructed via additional secondary interactions such as H-bonding and aromatic stacking. Notably, in situ hydrolysis reaction of 3-bpo is observed in the Pb^II complex with H₂TBTA, affording another dipyridyl-type ligand N,N′-bis(3-picolinoyl)hydrazine (3-bph). These results evidently reveal the significant substituent effect of terephthalic acid in structural direction of these metallosupramolecular systems that are also regulated by the selection of metal ions.     

Crystal structure of the 1 : 4 complex between 18-crown-6 and a polyfunctional guest: 2-hydroxymethyl-4-(1,1,3,3-tetramethylbutyl)phenol

Single crystal X-ray analysis of the 1 : 4 complex between 18-crown-6 and 2-hydroxymethyl-4-(1,1,3,3-tetramethylbutyl)phenol is reported. Crystals of the complex are triclinic witha = 11.929 (2),b = 18.655(2),c = 8.313(1)Å, = 93.14(1), = 94.02(1), = 100.89(1)^o, andD _c = 1.111 g cm^–3 forZ = 1. TheR index is 0.057 for 5935 reflections measured at 293 K. The complex lies on a center of symmetry, the macroring has the Ci symmetry (g ⁺ g ⁺ aag ^– aag ^– ag ^– g ^– aag ⁺ aag ⁺ a). The CH₂-OH group at theortho position to the phenolic OH lies near the benzene ring plane; this conformation differs from the one found for uncomplexed phenol-alcohol molecules. The packing is characterized by layers of hydrogen bonded entities parallel toac; alongb the layers are stabilized by van der Waals interactions.