Crystal Structure Of Coordination Polymer Research Articles

Synthesis and antimicrobial activity of vancomycin–conjugated zinc coordination polymer nanoparticles against methicillin-resistant staphylococcusaureus

Due to the overuse of antimicrobial drugs, Methicillin-resistant Staphylococcus aureus (MRSA) has caused a serious burden worldwide. Herein, we report a novel one-pot hydrothermal route to synthesize a vancomycin-encapsulated Zn-BTC-coordination polymer. FTIR and PXRD confirmed the composites and crystal structure of coordination polymer. The VAC-Zn-BTC-coordination polymer had a mean diameter, polydispersity index (PDI), zeta potential, and encapsulation efficiency of 59.6 ± 2.98 nm, 0.295 ± 0.0147, −11 ±-0.55 mV and 68.24 ± 3.412%, respectively at physiological pH. The safety of MTT in vitro in Human embryonic kidney 293 cells (HEK-293), adenocarcinomic human alveolar basal epithelial cells (A-549), and Michigan Cancer Foundation-7 (MCF-7) cell lines and the hemolytic assay of VAC-Zn-BTC-coordination polymer was evaluated. The in vitro results of the MTT assay were revealed to be safe in all three cell lines and non-hemolytic, thus indicating their biosafety. Molecular dynamics simulations (MDS) showed that higher binding and interaction energies were seen. The VAC release from the VAC-Zn-BTC-coordination polymer was slower than the powder VAC after 48 h. The VAC-Zn-BTC-coordination polymer revealed a lower MIC value of 1.02 μg/mL against MRSA with a 10-fold antimicrobial enhancement. The bactericidal time-kill kinetics assay showed that VAC-Zn-BTC-coordination polymer combinations showed good bactericidal effects over 24 h compared to bare VAC powder. These findings suggest that VAC-Zn-BTC-coordination polymer could be used as excellent potential for the improvement and management of bacterial contagions instigated by MRSA.

Synthetic Strategy for Incorporating Carboxylate Ligands into Coordination Polymers under a Solvent-Free Reaction

Solvent-free synthesis is a powerful approach for obtaining elusive crystal structures of coordination polymers (CPs) and metal–organic frameworks (MOFs). However, carboxylic acids were hardly empl...

Metal(II) Ion Dependence of the Structures and Properties of Square-Grid Coordination Polymers of Tetrabromobenzenedicarboxylate and Pyrazine as Bridging Ligands

Abstract In this study, we report the synthesis and crystal structures of coordination polymers employing tetrabromobenzenedicarboxylate (Br4bdc2−) and pyrazine (pyz). Uncoordinated pyz molecules are stabilized between the layers by both hydrogen H-bonding and π–π stacking interactions in [M(Br4bdc)(pyz)(H2O)2](pyz), where M = Co(II) and Zn(II). In addition, water molecules are incorporated between the layers in [Cu(Br4bdc)(pyz)(H2O)2](H2O) owing to Jahn–Teller distortion of the Cu(II) ions, which prevents π–π stacking interactions between the pyz and Br4bdc2−. Depending on the metal(II) centers, structural changes that occur during the heating and hydration processes exhibit different behavior. Co(II) compound slowly changes structure by heating and rapidly recovers the crystalline state in air. Conversely, Zn(II) compound assumes the amorphous phase by heating and slowly yields the crystalline phase in ambient conditions. Although the Cu(II) compound also shows structural changes by heating, the dehydrated phase exhibits hydrophobic characteristics. Ion conductivity measurements of the as-synthesized forms show conductivities of 1.9 × 10−6 Scm−1, 4.6 × 10−7 Scm−1, and 1.3 × 10−6 Scm−1, for the Co(II), Zn(II), and Cu(II) complexes at 90 °C and 95% relative humidity (RH), respectively. The relatively low values of the as-synthesized Co(II) and Zn(II) compounds are attributed to the H-bonding interaction and π–π stacking of pyz molecules, which prevent the dynamics of the pyz molecules needed for proton conduction.

Synthesis, Crystal Structures, and Photocatalytic Activity of Two Nickel(II) Coordination Polymers with Flexible Bis(benzimidazol-1-yl)alkane and Polycarboxylate Ligands

Two ternary Ni(II) coordination polymers (CPs) named as: {[Ni2(L1)2(1,8-NDC)2(H2O)2]·2H2O}n (1), {[Ni2(L2)1.5(FA)(H2O)3]·3.75H2O}n (2), (L1 = 1,6-bis(5,6-dimethylbenzimidazol-1-yl)hexane, L2 = bis(5,6-dimethylbenzimidazol-1-yl)methane, 1,8-H2NDC = 1,8-naphthalenedicarboxylic acid, H4FA = 4,4′-(hexafluoroisopropylidene)diphthalic acid) were hydrothermally synthesized and characterized through physicochemical and spectroscopic methods. CP 1 features a 1D double straight-line chain and further extends into a 2D layers via π–π stacking interactions, while CP 2 shows a unique 2D (5,4,4)-connected network. The thermal stabilities, luminescence properties and photocatalytic activities of CPs 1–2 for methylene blue decomposition were also presented in detail. Two luminescent Ni(II) coordination polymers (CPs) were synthesized under hydrothermal condition. The crystal structure of CP 1 features a 1D double straight-line chain and further extends into a 2D layers via π–π stacking interactions, while CP 2 shows a unique 2D (5,4,4)-connected network. The photocatalytic experiments in the presence of catalysts CP 1 indicated higher degradation efficiency for MB solution than CP 2, and ·OH radical plays a key effect in the efficient degradation of MB.

Crystal Structure of Coordination Polymers Based on Scandium and 2,5-Pyrazinedicarboxylic Acid

In the interaction of scandium chloride hexahydrate and 2,5-pyrazinedicarboxylic acid (H2pzc) dihydrate in different solvent mixtures two novel coordination polymers are obtained under solvothermal conditions: [Sc2(dmf)2(H2O)2(pzc)3] (1) and [Sc2(H2O)2(pzc)3]·2CH3CN·H2O (2) (dmf is N,N-dimethylformamide). Crystal structures of compounds 1 and 2 are determined by single crystal X-ray diffraction and supported by elemental and thermogravimetric data and IR spectroscopy. The phase purity of the samples prepared is confirmed by powder X-ray diffraction. It is shown that the coordination environment of the scandium cation and the 2,5-pyrazinedicarboxylate ligand denticity change depending on the composition of a solvent mixture. Compound 1 has a layered structure while in the structure of 2 there is a three-dimensional framework.

Кристаллическая структура координационных полимеров на основе скандия и 2,5-пиразиндикарбоновой кислоты

При взаимодействии гексагидрата хлорида скандия и дигидрата 2,5-пиразиндикарбо­новой кислоты (H2pzc) в различных смесях растворителей в сольвотермальных условиях получены два новых координационных полимера: [Sc2(dmf)2(H2O)2(pzc)3] (1) и [Sc2(H2O)2(pzc)3]⋅2CH3CN⋅H2O (2) (dmf — N,N-диметилформамид). Кристаллические структуры соединений 1 и 2 установлены методом рентгеноструктурного анализа монокристаллов и подтверждены данными элементного и термогравиметрического анализов и ИК спектроскопии. Фазовая чистота полученных образцов доказана с помощью метода рентгеновской дифракции на порошках. Показано, что в зависимости от состава смеси растворителей изменяется координационная сфера катиона скандия и дентатность 2,5-пиразиндикарбоксилатного лиганда. Соединение 1 имеет слоистую структуру, тогда как в структуре 2 реализуется трехмерный каркас.

Coordination polymers from dithiolato complexes and alkali metal cations: How a crystallizing and coordinating solvent influences the dimensionality

This article describes the influence of different solvents on the versatility of coordination-networks, formed from alkali metal coordination complex and transition metal bis(dithiolato) complex [M(btdt)2]1− (M = Cu(III) and Au(III); btdt = 2,1,3-benzenethiadiazole-5,6-dithiolate) in compounds 1–7: {[Na(CH3OH)4][Cu(btdt)2]}n (1), {[Na(THF)4][Cu(btdt)2]}n (2), {[Na(CH3COCH3)2][Cu(btdt)2]}n (3), {[Na(DMF)2][Cu(btdt)2]}n (4), {[Na(CH3CN)2][Cu(btdt)2]}n (5) {[Na(THF)2][Na(THF)(OH2)] [Au2(btdt)4]}n (6) and {[Na(CH3COCH3)2][Au(btdt)2]}n (7). The coordination polymers 1–5, based on copper(III)-bis(dithiolene) complex [CuIII(btdt)2]1−, are synthesized by the recrystallization of a dark-brown coloured precipitated precursor (P1) having a black appearance from the different solvents. The precursor P1 was obtained by the reaction of one mole equivalent of CuCl2·2H2O with two mole equivalents of H2btdt in MeOH, treated with an excess amount of NaOH in an open air atmosphere. For the preparation of compounds 6 and 7, AuCl3·2H2O was treated with H2btdt in MeOH containing NaOH to obtain precipitated precursor P2, which was recrystallized from THF and acetone to produce single crystals of 6 and 7 respectively. In the crystal structures of coordination polymers 1–7, where sodium coordination complex is a cationic component, the dimensionality of the networks of the resulting coordination polymers has greatly been influenced by the nature of hybridization of central carbon atom of the sodium-coordinated solvent, which happens to be the recrystallizing solvent. In order to investigate the influence of the counter cation on the structural diversity and dimensionality, we have compared the supramolecular chemistry of these sodium metal based coordination polymers 1–7 with that of our previously reported potassium-based coordination polymers {[K(CH3COCH3)3][Cu(btdt)2]}n and {[K(CH3CN)2][Cu(btdt)2]}n. All these compounds have been characterized unambiguously by single crystal X-ray crystallography and routine spectroscopy (IR, UV-visible and NMR). Interestingly, copper compounds 1 and 3–5 exhibit two quasi-reversible reduction responses at −0.13 V and −1.10 V vs Ag/AgCl respectively in DMF solutions.

Synthesis, Characterization and Crystal Structure of Coordination Polymers Developed as Anion Receptor

Reaction of diamide ligand, namelyN,N’-2,6-bis (4-pyridylmethyl) pyridine dicarboxamide (L) with cadmium nitrate and cadmium perchlorate has given rise to the formation of two types coordination polymers. Compound (CP1-Cd) with formula molecule {[Cd (L)2(H2O)2](NO3)2·6H2O}nis a one-dimensional coordination polymer while compound (CP2-Cd), with formula molecule {[Cd (L)2(H2O)2](ClO4)2·31⁄2H2O.CH3OH}n, is a two dimensional coordination polymer. These coordination polymers were preparedviaslow evaporation methods and completely characterized by combination of solid state techniques such as Fourier Transform Infrared (FTIR) spectroscopy, elemental analysis and X-ray crystallography. This study revealed that coordination polymers derived fromN,N’-2,6-bis (4-pyridylmethyl) pyridine dicarboxamide can accommodate anions with different sizes, showing good potential as anion receptor.

Crystal Structure of Coordination Polymers Based on A Heterometallic Carboxylate Complex

Three new metal-organic frameworks [Zn(Hibdc)2]·DMF (1), (H2NMe2)[Li2Zn3(H2O)(dmf)(Hbtc)3(btc)]·6DMF·H2O (2), and [Li2Zn2(H2O)2(bpp)(bpdc)3]·7DMF (3) are obtained in the interaction of heterometallic carboxylate complex [Li2Zn2(piv)6(py)2] with isophthalic (H2ibdc) and trimesic (H3btc) acids and in the presence of both 4,4′-biphenyldicarboxylic acid (H2bpdc) and 4,4′-bispyridylpropane (bpp). The structure of the obtained compounds is determined by the single crystal X-ray diffraction analysis. In the reactions studied the structure of the initial {Li2Zn2} fragment is not retained. A complicated fragmentation of this four-nuclear block occurs, including the formation of binuclear heterometallic dimers {LiZn}.

Кристаллическая структура координационных полимеров, полученных на основе гетерометаллического карбоксилатного комплекса

При взаимодействии гетерометаллического карбоксилатного комплекса состава [Li2Zn2(piv)6(py)2] с изофталевой кислотой (H2ibdc), тримезиновой кислотой (H3btc) и в присутствии как 4,4'-бифенилдикарбоновой кислоты (H2bpdc), так и 4,4'-биспири­дилпропана (bpp) получены три новых металл-органических координационных полимера [Zn(Hibdc)2]·DMF (1), (H2NMe2)[Li2Zn3(H2O)(dmf)(Hbtc)3(btc)]·6DMF·H2O (2) и [Li2Zn2(H2O)2(bpp)(bpdc)3]·7DMF (3). Структура полученных соединений установлена методом рентгеноструктурного анализа монокристаллов. В изучаемых реакциях структура исходного фрагмента {Li2Zn2} не сохраняется. Происходит сложная фрагментация этого четырехъядерного блока, в том числе с образованием биядерных гетерометаллических димеров {LiZn}.

Synthesis, Crystal Structure and Luminescent Properties of 2D Zinc Coordination Polymers Based on Bis(1,2,4-triazol-1-yl)methane and 1,3-Bis(1,2,4-triazol-1-yl)propane

Two new two-dimensional zinc(II) coordination polymers containing 2,5-thiophenedicarboxylate and bitopic ligands bis(1,2,4-triazol-1-yl)methane (btrm) or 1,3-bis(1,2,4-triazol-1-yl)propane (btrp) were synthesized. Synthesized compounds were characterized by IR spectroscopy, elemental analysis, powder X-ray diffraction, and thermal analysis. Crystal structures of coordination polymers were determined and their structural peculiarities are discussed. The differences in structural features, thermal behavior, and luminescent properties are discussed.

Self-assembly and crystal structures of coordination polymers constructed by 4′-hydroxyisoflavone-3′-sulfonates with Cs(I) and Rb(I)

Four coordination polymers, [CsL1(H2O)2]·H2O (1), [CsL2(H2O)2]·H2O (2), [Rb2(L2)2(H2O)2]·2H2O (3) and [RbL3(H2O)] (4), were synthesized by Cs(I), Rb(I) and 4′-hydroxyisoflavone-3′-sulfonates L1–L3 [L1 = 7-methoxy-4′-hydroxyisoflavone-3′-sulfonate, L2 = 7-ethoxy-4′-hydroxyisoflavone-3′-sulfonate, L3 = 7-ethoxy-4′,5-dihydroxyisoflavone-3′-sulfonate]. The crystal structures of 1–4 were determined by single-crystal X-ray diffraction. The influences of 4′-hydroxyisoflavone-3′-sulfonate ligands and Cs+, Rb+ on their structural features and self-assembly were investigated. The sulfonates of L1–L3 not only coordinate with Cs+ or Rb+ directly, but also bridge the organic region and the inorganic region in 1–4. Non-covalent interactions such as coordination interaction, π–π stacking interaction and hydrogen bonding assembled 1–4 into 3-D networks together with the electrostatic interactions between Cs+, Rb+ and the sulfonate anions.

Synthesis, Crystal Structure and Thermal Stability of 1D Linear Silver(I) Coordination Polymers with 1,1,2,2-Tetra(pyrazol-1-yl)ethane

Two new linear silver(I) nitrate coordination polymers with bitopic ligand 1,1,2,2-tetra(pyrazol-1-yl)ethane were synthesized. Synthesized compounds were characterized by IR spectroscopy, elemental analysis, powder X-ray diffraction and thermal analysis. Silver coordination polymers demonstrated a yellow emission near 500 nm upon excitation at 360 nm. Crystal structures of coordination polymers were determined and structural peculiarities are discussed. In both of the structures, silver ions are connected via bridging ligand molecules to form polymeric chains with a five-atomic environment. The coordination environment of the central atom corresponds to a distorted trigonal bipyramid with two N atoms of different ligands in apical positions. The Ag–N bond distances vary in a wide range of 2.31–2.62 Å, giving strongly distorted metallacycles. Thermolysis of coordination polymers in reductive atmosphere (H2/He) leads to the formation of silver nanoparticles with a narrow size distribution.

Crystal structures of coordination polymers from CaI2 and proline.

Completing our reports concerning the reaction products from calcium halides and the amino acid proline, two different solids were found for the reaction of l- and dl-proline with CaI2. The enanti-opure amino acid yields the one-dimensional coordination polymer catena-poly[[aqua-μ3-l-proline-tetra-μ2-l-proline-dicalcium] tetra-iodide 1.7-hydrate], {[Ca2(C5H9NO2)5(H2O)]I4·1.7H2O} n , (1), with two independent Ca(2+) cations in characteristic seven- and eightfold coordination. Five symmetry-independent zwitterionic l-proline mol-ecules bridge the metal sites into a cationic polymer. Racemic proline forms with Ca(2+) cations heterochiral chains of the one-dimensional polymer catena-poly[[di-aquadi-μ2-dl-proline-calcium] diiodide], {[Ca(C5H9NO2)2(H2O)2]I2} n , (2). The centrosymmetric structure is built by one Ca(2+) cation that is bridged towards its symmetry equivalents by two zwitterionic proline mol-ecules. In both structures, the iodide ions remain non-coordinating and hydrogen bonds are formed between these counter-anions, the amino groups, coordinating and co-crystallized water mol-ecules. While the overall composition of (1) and (2) is in line with other structures from calcium halides and amino acids, the diversity of the carboxyl-ate coordination geometry is quite surprising.

Synthesis and Crystal Structure of Coordination Polymers of Yttrium and Holmium with Hydrogen Succinate and Benzene-1,3-disulphonate

Synthesis and crystal structures of two coordination polymers [Y(1,3-BDS)(HSA)(H2O)4] n and [Ho(1,3-BDS)(HSA)(H2O)4] n (1,3-BDS = Benzene-1,3-disulphonate and H2SA = Succinic acid) having one-dimensional zig-zag polymeric structure and containing yttrium and holmium in +3 oxidation state are reported. Coordination polymers [Y(1,3-BDS)(HSA)(H2O)4] n and [Ho(1,3-BDS)(HSA)(H2O)4] n are isostructural as deduced from single crystal X-ray diffraction analysis and contain distorted square antiprism geometry around metal ions. Two molecules of benzene-1,3-disulphonate and uninegative hydrogen succinate each coordinate to metal ions in unidendate bridging mode to generate a linear zig-zag polymeric chain. Four water molecules are also coordinated to each metal ion. Charge-assisted hydrogen bonds involving coordinated water molecules and sulphonate and carboxylate groups generate strong intramolecular and inter-chain interactions leading to two-dimensional polymer expansion.

Syntheses and crystal structures of coordination polymers of a porphyrin ligand bearing two pyridyl and two carboxyl moieties

In this work, we designed and synthesized a porphyrin-based ligand, 5,15-bis(4-carboxyphenyl)-10,20-dipyridyl porphyrin, DCDPP (H4L), which bears two carboxyl and two pyridyl moieties. Coordination of Mn(II) and Zn(II) acetates with DCDPP afforded two novel coordination polymers, [MnHL]n (1) and [ZnH2L]n·nCH3COOH (2), respectively. Single crystal X-ray diffraction analyses revealed that complex 1 exhibits 2D coordination networks, which are further linked through hydrogen bonds to form a 3D network structure. In complex 2, 1D zigzag coordination chains were generated and further linked through hydrogen bonds to form a 2D structure. Interestingly, the carboxyl moieties in these complexes are noncoordinated, and the pyridyl moieties are either coordinated or noncoordinated, and the noncoordinated carboxyl and pyridyl moieties are involved in intermolecular hydrogen bonds, which are favorable for forming the hydrogen-bonded networks.

Syntheses, studies and crystal structures of coordination polymers and dinuclear complexes of mercury(II) halides and thiocyanate with a symmetrical Schiff base ligand

A series of mercury(II) compounds, [Hg2(μ-L)(SCN)4]n (1), [Hg2(μ-L)(μ-Cl)2Cl2]n (2), [Hg2(μ-L)Br4].[Hg2(μ-L)(μ-Br)2Br2]n (3) and [Hg2(μ-L)I4] (4) {L=N,N′-(bis-(pyridin-2-yl)benzylidene)-1,2-ethanediamine} have been prepared and characterized by using microanalytical, spectroscopic, thermal and X-ray crystallographic results. In solid states 1 and 2 have 2D and 1D coordination polymer structure, respectively. Solid state 3 consists of both 1D coordination polymers and dinuclear units. Solid state 4 is only composed of dinuclear units. In the polymeric structures, each mercury(II) center is five coordinated with trigonal bipyramidal geometry in 1D and square pyramidal environment in 2D coordination polymers. Coordination geometry around Hg centers in dinuclear units is tetrahedral. HOMO and LUMO of the title compounds and also the energy gap among them have been studied by using the density functional theory (DFT/B3LYP) method with the LANL2DZ pseudo-potential.

Synthesis and properties of ZnII and CdII complexes with chiral N-derivatives of aminoacetic acid based on natural monoterpenes (+)-3-carene and (−)-α-pinene. Crystal structure of coordination polymer [Zn(HL)Cl·2H2O] n

Chiral sodium salts of N-derivatives of aminoacetic acid based on (+)-3-carene (HLNa) and (−)-α-pinene (HLNa) were synthesized. Complexes Zn(HL)Cl (1), Cd(HL)Cl·0.5H2O (3), Zn(HL′)Cl·0.5H2O (4), and Cd(HL′)Cl·0.5H2O (5) were obtained. The single crystals of the coordination polymer [Zn(HL)Cl·2H2O] n (2) were grown. According to the X-ray diffraction analysis, the crystal structure of 2 consists of 1D chains built of Zn(HL)Cl and water molecules. The coordination polyhedron ClN2O2 is a distorted square pyramid. The HL− ligand performs the chelating tetradentate-bridging function, and the COO− group binds two adjacent Zn atoms. The IR spectroscopy data for compounds 1 and 3–5 indicate the coordination of the COO−, NOH, and NH functional groups. The excitation and photoluminescence (PLM) spectra of the solid samples of compounds HLNa, HL’Na, 1, and 3–5 were recorded at room temperature. The compounds exhibit blue PLM. The intensity of PLM of the CdII complexes is higher than that of the ZnII complexes, which is a characteristic feature of PLM of the studied compounds.

Synthesis and crystal structures of coordination polymers, networks and complexes of an adamantane shaped phosphorus–nitrogen cage ligand and cuprous chloride

Reactions of cuprous chloride with the phosphorus–nitrogen cage ligand 2,4,6,8,9,10-hexamethyl-2,4,6,8,9,10-hexaaza-1,3,5,7-tetraphosphaadamantane, P 4(NCH 3) 6, in acetonitrile form distinct solids depending on the ligand-to-metal ratio. Three structurally characterized compounds include: a solvated 3-D network of formula [P 4(NCH 3) 6] 2(CuCl) 3(CH 3CN) 2; a “ladder-type” polymer {[μ 2-P 4(NCH 3) 6] 2(CuCl) 2} ∞; and a monomeric complex [P 4(NCH 3) 6] 2CuCl. Thermal decomposition of the solvated network results in formation of two more materials [P 4(NCH 3) 6] 2(CuCl) 3, and [P 4(NCH 3) 6](CuCl) 2 that are not isolated from solution reactions. The variety of products isolated based solely on ligand-to-metal ratio suggest that this system participates in solution equilibria common to many phosphorus(III) ligands and multiple solubility equilibria.

Syntheses, characterization, and crystal structures of coordination polymers: {NH4 · [Ln(OVA)4]} n (Ln=Pr, Nd, Gd, and Ho; OVA=2-hydroxy-3-methoxybenzoate)

The title complexes {NH4 · [Ln(OVA)4]} n (Ln = Pr, Nd, Gd, and Ho; OVA = 2-hydroxy-3-methoxybenzoate) were synthesized in water and characterized by FT-IR, elemental analysis, TGA, and X-ray single-crystal diffraction analysis. Two distinct structure types were isolated. Structure type I with formula {NH4 · [Ln(OVA)4]} n (Ln = Pr, Nd, Gd) contains Ln–COO− quadruply-bridged helical 1-D chains, with all carboxylates bridging. The structure type II with formula {NH4 · [Ho(OVA)4]} n contains bridging and chelating carboxylates, resulting in Ho–COO− double helical 1-D chains. The passage from type I to type II structure is ascribed to the lanthanide contraction. These 1-D chains are extended to 3-D supramolecular architecture by hydrogen bonds.