Salen Type Sandwich Triple-Decker Tri- and Di-nuclear Lanthanide Complexes

Four N,N′-bis(salicylidene)-1,2-(phenylene-ediamine) (H₂L) trinuclear lanthanide complexes, namely, [Ln₃L₃(CH₃OH)₂(NO₃)₃]·(CH₂Cl₂)·(CH₃OH)·(H₂O)₂ [Ln = Tb (1), Ho (2), Er (3) and Lu (4)], have been isolated by the reactions of H₂L and Ln(NO₃)₃·6H₂O. And one N,N′-bis(salicylidene)-1,2-(phenylene-ediamine) dinuclear neodymium complex [Nd₂L₃(CH₃OH)] (5) has been harvested from the reaction of H₂L with Nd(OAc)₃·4H₂O. X-ray crystallographic analysis reveals that complexes 1?4 are of triple-decker trinuclear sandwich structure, while complex 5 is of a triple-decker dinuclear sandwich structure, expanding upon the recent reports of the multinuclear pure lanthanide complexes.     

Oxidation of Benzene Catalyzed by 2,2′-Bipyridine and 1,10-Phenantroline Cu(II) Complexes

The use of mononuclear Cu(II) 2,2′-bipyridine and 1,10-phenantroline complexes as catalysts in the oxidation of benzene, using hydrogen peroxide and tert-butyl hydroperoxide as oxidant in CH₃CN/H₂O solution is presented. The reactions were carried out at 25 and at 50 °C. The complexes [Cu(bipy)₃]Cl₂ · 6H₂O (1), [Cu(bipy)₂Cl]Cl · 5H₂O (2), [Cu(bipy)Cl₂] (3), [Cu(phen)₃]Cl₂ · 7H₂O (4), [Cu(phen)₂Cl]Cl · 5H₂O (5), [Cu(phen)Cl₂] (6) were able to oxidize benzene into phenol, hydroquinone and p-benzoquinone. Highest conversion (22%) was obtained using [Cu(Phen)Cl₂] (6) as catalyst.     

Salen Type Homo-multinuclear Yb3 and Yb4 Complexes and Their NIR Luminescence

Two discrete salen type homo-multinuclear Yb₃ and Yb₄ complexes, namely, [Yb₃L₃(OAc)₃]·3CH₃OH·H₂O (1) and [Yb₄L₂(OAc)₄(μ₃-OH)₂(H₂O)₂](ZnCl₄)·3CH₃OH (2) (H₂L = N,N′-bis(2-oxy-3-methoxybenzylidene)-1,2-phenylenediamine) have been synthesized by reactions of H₂L and different ytterbium salts. X-ray crystallographic analysis reveals that complex 1 exhibits a triple-decker Yb₃ sandwich structure with a ratio of H₂L:Yb = 1:1, while complex 2 exhibits a defect-dicubane Yb₄ core with a ratio of H₂L:Yb = 1:2. The NIR luminescence of complexes 1 and 2 have been investigated and discussed.     

The Inclusion of Organometallic Derivatives of Cyclotriphosphazenes Inside SiO2 Matrix and Their Conversion to Nanostructured Metal-Oxides and Phosphates

Organometallic derivatives of the cyclotriphosphazene N₃P₃[OC₆H₄CH₂CN·TiClCp₂]₆ (1), N₃P₃(O₆H₅)₅[OC₆H₄N·W(CO)₅] (2), N₃P₃[OC₆H₄CH₂CN·Mo(CO)₅]₆ (3), [N₃P₃(O₆H₅)₅(OC₅H₄N·CpRu(PPh₃)₂)][PF₆] (4), [N₃P₃(O₂C₁₂H₈)₂OC₅H₄N·Ag(PPh₃)][OSO₂CF₃] (5), N₃P₃[OC₆H₅]₅ [OC₅H₄N·Cu][PF₆] (6) and N₃P₃[OC₆H₄CH₂CN·CuCl]₆[PF₆]₆ (7),were incorporated inside SiO₂ through the sol–gel method. The metal–organic nanocomposites of the general formula N₃P₃[OC₆H₄CH₂CN·TiClCp₂]₆·nSiO₂ (G ₁ ), N₃P₃[OC₆H₄N·W(CO)₅]·nSiO₂ (G ₂ ), N₃P₃[OC₆H₄CH₂CN·Mo(CO)₅]₆·nSiO₂ (G ₃ ), N₃P₃(O₆H₅)₅OC₅H₄N·CpRu(PPh₃)₂][PF₆]·nSiO₂ (G ₄ ), [N₃P₃(O₂C₁₂H₈)₂OC₅H₄N·Ag(PPh₃)][OSO₂CF₃]·nSiO₂ (G ₅ ), N₃P₃[OC₆H₅]₅[OC₅H₄N·Cu][PF₆]·(SiO₂) _n (G ₆ ), and N₃P₃[OC₆H₄CH₂CN·CuCl]₆[PF₆]₆·(SiO₂) _n (G ₇ ), were characterized by IR spectroscopy; ¹²C, ³¹ P and ²⁹Si MAS NMR measurements as well as UV–Visible diffuse reflectance spectra, indicating the presence of the respective organometallic derivatives of the cyclotriphosphazene incorporated into SiO₂. Pyrolysis of these nanocomposites under air at 800 °C gives rise to nanostructured metal-oxides and metal phosphates incorporated into amorphous SiO₂, with the presence in some cases of complexes phase mixtures. From some precursors, we obtained metal-oxides/phosphates nanoparticles separated from the SiO₂ nanoparticles instead the oxides/phosphates nanoparticles inside the SiO₂ matrix. Additionally and for comparison purposes, we used the compound N₃P₃[NH(CH₂)₃Si(OEt)₃]₆ as gelator. Nanocomposites (G′ ₁ ), (G′ ₂ ) and (G′ ₃ ) exhibited mainly morphological differences while in some cases composition differences when using TEOS as gelator. Some simple metal-containing compounds as (O₃SCF₃)Ag(PPh₃)(HOC₅H₄N), [CuCl₂·NC₅H₄OH] and [CuCl₂·NCCH₂C₆H₄OH]—which are useful models of the most complexes (G ₅ ), (G ₆ ) and (G ₇ ) were also prepared and incorporated in amorphous silica. Their pyrolytic products were compared with those of more complex cyclotriphosphazene analogous. Interestingly, the pyrolysis of the nanocomposite [(O₃SCF₃)Ag(PPh₃)(HOC₅H₄N)][SiO₂] _n affords the firstly-reported materials containing Ag₂O along with SiO₂ nanoparticles.     

Synthesis,Crystal Structure and Luminescent Property of a New Zn(II) Coordination Polymer with Twofold Interpenetrated pcu Topology

A new Zn(II) coordination polymer; namely, [Zn(FA)(bmix)_0.5] _n ·nH₂O (1, H₂FA = fumaric acid, bmix = 1,4-bis(2-methyl-1H-imidazol-1-ylmethyl)benzene) was synthesized with fumaric acid and flexible 2-methylimidazole-based ligands with Zn(II) salts under hydrothermal conditions. Single-crystal X-ray diffraction reveals that 1 features a twofold interpenetrating three-dimensional pillar-layered framework based on paddle-wheel shaped [Zn₂(COO)₄] subunits. The structure may be simplified to a 6-connected pcu topological network. Luminescent investigation reveals that 1 exhibits intense ligand-centered fluorescence at room temperature.     

Hydrothermal Syntheses and Photoluminescent Properties of Two Zinc(II) Coordination Polymers Based on 4,6-di(1<Emphasis Type="Italic">H</Emphasis>-imidazol-1-yl)-1,3,5-triazin-2-ol

Two new Zn(II) coordination polymers based on the tridentate ligand 4,6-di(1H-imidazol-1-yl)-1,3,5-triazin-2-ol (Hdit), namely, {[Zn(dit)₂(H₂O)₂]·4H₂O}_n (1) and [Zn(dit)(CH₃COO)]_n (2), have been successfully constructed by varying the metal salts. Compound 1 shows 1D zigzag chain structure, and compound 2 is a 3D binodal (3,5)-connected architecture with {4²·6⁶·8²}{4²·6} topology. The photoluminescent spectra indicate that at room temperature, compounds 1 and 2 emit violet and blue luminescence, respectively.     

Syntheses, Structures and Magnetic Properties of Two Novel Cu(II) Diphosphonate Coordination Polymers with N-Heterocyclic Auxiliary Ligand

By introducing the second organic N-heterocyclic ligand 2,2′-bipyridine (2,2′-bipy), two binuclear examples of Cu(II)-diphosphonate coordination polymers based on 1-hydroxyethylidenediphosphonic acid (H₅L=CH₃C(OH)(PO₃H₂)₂), [Cu₂(H₄L)₂(H₃L)(2,2′-bipy)₂] 1 and [Cu(H₃L)(2,2′-bipy)] 2, have been hydrothermally obtained and characterized by powder X-ray diffraction, elemental analysis, IR, TG-DSC. The single-crystal X-ray diffractions show that both the two compounds possess zero-dimensional binuclear structures built through a single O–P–O bridge for 1 and a double O–P–O bridge for 2 in syn–anti fashion. Then H-bond and π–π interactions further expand the two zero-dimensional binuclear structures into three-dimensional supramolecular frameworks. Fluorescent measurements reveal that the maximum emission peaks of 1–2 centered at 423.5 nm for 1 and 423 nm for 2, respectively, are mainly caused by intraligand π*–π emission state of N-heterocyclic ligand 2,2′-bipy (λ _ex = 233 nm). The further magnetic study shows the two coordination polymers exhibit ferromagnetic behaviors derived from O–P–O bridges in syn–anti mode between the metal centers.     

Two Supramolecular Microporous Metal–Organic Frameworks Templated by Keggin Polyoxometalates

Two new Keggin polyoxometalates (POM)-templated supramolecular metal–organic frameworks (MOF) with micropores, Cu₃(L)₆[H₃(PMo₁₂O₄₀)₂]·6H₂O (1) and Cu₃(L)₆[H₅(SiW₁₂O₄₀)₂]·6H₂O (2) (L?=?1,2-bis(imidazol-1-ylmethyl)ethane), have been prepared under hydrothermal conditions and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra and cyclic voltammetry. These two isostructural compounds are constructed by two distinct moieties, a Keggin polyanion and a linear [Cu(L)₂]⁺ subunit. The [Cu(L)₂]⁺ subunits further form a microporous MOF through supramolecular interactions. The Keggin polyanions act as templates inducing the micropores. The electrochemical and electrocatalytic behavior of compounds 1 and 2 bulk-modified carbon paste electrodes (1-, 2-CPE) was studied.     

Uranyl Coordination Polymers Incorporating η5-Cyclopentadienyliron-Functionalized η6-Phthalate Metalloligands: Syntheses,Structures and Photophysical Properties

The reaction of two η⁵-cyclopentadienyliron(II)-functionalized terephthalate and phthalate metalloligands, namely [(η⁵-C₅H₅)Fe^II(η⁶-1,4-HO₂CC₆H₄CO₂H)][(η⁵-C₅H₅)Fe^II(η⁶-1,4-HO₂CC₆H₄CO₂)][PF₆] and [(η⁵-C₅H₅)Fe^II(η⁶-1,2-HO₂CC₆H₄CO₂H)][(η⁵-C₅H₅)Fe^II(η⁶-1,2-HO₂CC₆H₄CO₂)][PF₆]—hereafter [H₂ CpFeTP][HCpFeTP][PF₆] and [H₂ CpFeP][HCpFeP][PF₆], respectively—with [UO₂(NO₃)₂]·6H₂O under hydrothermal conditions yielded four new coordination polymers; (1) [(UO₂)F(HCpFeTP)(PO₄H₂)]·2H₂O, (2) [(UO₂)₂(CpFeTP)₄]·5H₂O, (3) [(UO₂)₂F₃(H₂O)(CpFeP)], and (4) [H₂ CpFeP][UO₂F₃]. The use of metalloligands has proven to be a viable route towards the incorporation of a secondary metal center into uranyl bearing materials. Depending upon the protonation state, the iron sandwich metalloligands may vary from zwitterionic neutral or monoanionic coordinating species as observed in compounds 1–3, or a positively charged species that hydrogen bonds with anionic [UO₂F₃]^? chains as observed in 4. Further, the hydrolysis of the charge balancing PF₆ ^? anion increases the diversity of UO₂ ²⁺ coordinating species by contributing both F^? and PO₄ ^3? anions (1, 3, 4). The luminescent properties of 1–4 were also studied and revealed the absence of uranyl emission, suggestive of a possible energy transfer from the uranyl cation to the iron(II) metal center.     

Synthesis and Crystal Structures of a Lanthanum(III) 1D Polymer and a Mixed-Ligand Cerium(III) Binuclear Complex Derived from Pyridine-2,6-dicaboxylic Acid

Lanthanum(III) and cerium(III) complexes of pyridine-2,6-dicaboxylic acid (H₂Pydc) have been prepared and their crystal structures were determined by X-ray crystallography. The single crystal analysis reveals that the lanthanum(III) complex, 1 is polymeric consisting of {[La(Pydc)₂(H₂O)₂]·4H₂O} _n units linked through carboxylate oxygen atoms and exhibiting nine coordination number. Intermolecular O–H···O hydrogen bonds produce R ₁ ¹ (6), R ₄ ⁴ (16) and R ₄ ⁴ (20) rings, which lead to three-dimensional polymeric chains. The crystal structure of the cerium(III) complex, 2 [{Ce(Pydc)₃}{Ce(Pydc)(HO–CH₂CH₂–OH)(H₂O)₃}·6H₂O)] shows that the complex is a mixed-ligand binuclear system in which one cerium coordinated to three Pydc molecules, while the other cerium is bound to one Pydc, one oxygen atom of the other Pydc, one ethylene glycol and three water molecules. Each of the two Ce(III) ions is nine coordinated. Intermolecular O–H···O hydrogen bonds produce R ₂ ² (8) and R ₂ ² (20) rings, which lead to three-dimensional polymeric chains. The complexes were further investigated using elemental analysis, FTIR spectroscopy and thermogravimetric analysis.     

Three-Dimensional Structure of Barium–Cupric Nitrilotriacetate and One-Dimensional Structure of Cobalt–Cupric Nitrilotriacetate: Template Effect of Cations on the Formation of Coordination Polymers

Three mixed-metal nitrilotriacetates [Ba(H₂O)₃Co(nta)Cl]_n (1), [Ba(H₂O)₃Ni(nta)Cl]_n (2), and [Ba(H₂O)₃Cu(nta)Cl]_n (3) (H₃nta = nitrilotriacetic acid) were prepared by the reaction of M²⁺ ions (M = Co, Ni, and Cu), K₃nta, and Ba²⁺ ions in water. The reaction of complexes 1 and 2 with CuSO₄·5H₂O afforded [Co(H₂O)₆]_n[Cu₂(nta)₂]_n·2nH₂O (4) and [Ni(H₂O)₆]_n[Cu₂(nta)₂]_n·2nH₂O (5), respectively. The reaction mechanism was elucidated. The crystal structure analyses indicate that the Ba²⁺ ions formed one-dimensional (1D) zigzag chains in complex 3, and the chains were connected by Cu(nta)^? anions to form a three-dimensional network. On the other hand, in complexes 4 and 5, the Cu(nta)^? anions formed 1D zigzag chains, and the [Co(H₂O)₆]²⁺ (or [Ni(H₂O)₆]²⁺) cations existed as isolated units.     

Ancillary Ligand-Mediated Syntheses,Structures and Fluorescence of Three Zn/Cd(II) Coordination Polymers Based on Nitrobenzene Dicarboxylate

The Zn/Cd(II)-nbdc carboxylate motifs mediated by various dipyridyl-typed ligands afforded three new coordination compounds, namely, [Zn(nbdc)(bpa)_0.5(H₂O)]·H₂O (1), [Zn₂(nbdc)₂(bpp)₂]·H₂O (2), and [Cd(nbdc)(bpe)_0.5(H₂O)₂] (3) (H₂nbdc = 4-nitrobenzene-1,2-dicarboxylic acid, bpa = 1,2-bi(4-pyridyl)ethane, bpe = 1,2-di(4-pyridyl)ethylene, and bpp = 1,3-bis(4-pyridyl)propane), which were synthesized by hydrothermal reaction and characterized by elemental analysis, IR, thermal analysis (TGA), and fluorescent analysis. The single-crystal X-ray diffractions reveal that three complexes display a diverse range of connectivity topology from 1D to 3D, which is dependent on the type of dipyridyl-typed ligands and metal centers. Complex 1 is the 1D chain featuring Zn-carboxylate binuclears extended further by bpa coligands. Complex 2 is the 2D thick-layer containing double-stranded chains cross-linked further by bpp coligands. Complex 3 is the 3D framework with (6³)(6⁵.8) ins topology featuring Cd-carboxylate chiral layers pillared by bpe coligands. The thermal stabilities and fluorescence properties for complexes 1–3 are investigated.     

Tris-Alkoxylphenylterpyridine Cobalt(II) Complexes: Synthesis, Structure, and Magnetic and Mesomorphic Behaviors

Two novel cobalt(II) complexes [Co(L1)₂](BF₄)₂·CH₃CN·0.5H₂O (1) and [Co(L2)₂](BF₄)₂ (2) (L1 = 4′-(3,4,5-trimethoxy-phenyl)-[2,2′:6′,2″]terpyridine, L2 = 4′-(3,4,5-tris-hexadecyloxy-phenyl)-[2,2′:6′,2″]terpyridine) have been synthesized, and their structural, magnetic and mesomorphic properties were characterized by single crystal X-ray diffraction (XRD) analysis, temperature-dependent magnetic susceptibility, POM, DSC, and powder XRD analysis. The molecular structure of the complex 1 with short alkyl substituents exhibited that the metal ion has an N₆ coordination sphere of distorted octahedral geometry and various intermolecular π–π interactions are important factors influencing the crystalline array. The magnetic behaviour of 1 displayed a typical of gradual spin transition for cobalt(II) terpyridine complexes. On the other hand, the complex 2 possessing linear long alkyl chains showed a gradual spin transition between low-spin and high-spin with a thermal hysteresis loop (T _1/2↑ = 338 and T _1/2↓ = 327 K) triggered by the crystal-to-mesophase transition. The powder XRD and POM analyses were indicative of the liquid crystalline lamellar phase of 2.     

Hydrothermal Syntheses,Crystal Structure and Luminescent Properties of Two New Zn(II) Coordination Polymers

Two new zinc(II) coordination polymers; namely, [Zn(BDC)(L)_0.5]_n (1) and {[Zn(BDC)(L)]·3H₂O}(2), were successfully synthesized by the assembly of Zn(II) ion, 1.2-benzene-dicarboxylate acid (H₂BDC) and 1,4-bis(2-methylimidazole-3-ium-1-yl) biphenyl (L). A change in the pH values resulted in complexes with different compositions and dimensionalities. Formed at the lower pH, 1 exhibits a three-dimensional structure with mab topology. At a higher pH, 2 shows a two-dimensional structure, which contains one-dimensional helical chains. The luminescent properties for 1 and 2 were investigated in the solid state at room temperature.     

Three New Metal–Organic Polymers Based on Flexible 3-(4-(Carboxymethoxy) Phenyl) Propanoic Acid: Crystal Structures, Luminescent and Magnetic Properties

Three new metal–organic coordination complexes, [Zn₂L(bpp)₂Cl₂] _n (1), [ZnL(bipy)] _n (2), [NiL(bipy)(H₂O)] _n (3), have been synthesized through hydrothermal reactions of flexible 3-(4-(carboxymethoxy)phenyl) propanoic acid(H₂L) with different pyridyl-containing 1,3-bis(4-pyridyl)propane(bpp) or 4,4′-bipyridine(bipy) ligand, and they are characterized by elemetal analysis and single-crystal X-ray diffraction techniques. Complex 1 has a 2-D layer supramolecular network composed of 1-D distorted trapezoidal chains via C–H···π stacking interactions. Complex 2 displays a 2-D lattice-shaped layer structure. Complex 3 has three kinds of O–H···O intermolecular hydrogen bonds, exhibiting a 3-D supramolecular framework. The luminescent properties of complex 1 and 2 have indicated the mixture characteristic of intraligand and ligand-to-ligand charge transition. The magnetic property of 3 has shown the ferromagnetic coupling between Ni²⁺ ions.     

Structural, Theoretical and Multinuclear NMR Study of a New Polymeric Mercury(II) Complex with an Ambidentate Phosphorus Ylide

The reactions of phosphorus ylides of the type Ph₃P=C(H)C(O)R [R = 2,4-dichlorophenyl (L ¹ ) and 4-isopropylphenyl (L ² )] with HgX₂ [X = Cl (1, 4), Br (2, 5) and I (3, 6)] salts using methanol as a solvent are reported. Single crystal X-ray analysis carried out on L ¹ , 2 and 3 and reveals the presence of a novel polymeric structure for 2 and a centrosymmeteric dimeric structure for 3. The complexes have been studied by elemental analyses, IR, ¹H and ³¹P NMR spectroscopy. On the basis of DFT calculations, the formation of [Hg₂Br₆]^2? anions in 2 has a key role in the formation of the polymeric structure; and, the formation of [Hg₂L₂I₄] molecule thermodynamically is about 25 kcal/mol more favorable than the corresponding [Hg₂L₂Br₄] molecule.     

Syntheses, Characterization and Crystal Structures of Diorganotin(IV) Selenites: 1D Helical Double-Chain Containing Eight-Membered Sn2O4Se2 Inorganic Ring

Three new diorganotin(IV) selenites, [Bu₂Sn(O₂SeC₆H₅OMe)₂]_n (1), [Me₂Sn(O₂SeC₆H₄CHMe₂)₂]_n (2), [Me₂Sn(O₂SeC₆H₄Et)₂]_n (3) have been synthesized and structurally characterized by elemental analysis, FT-IR, NMR (¹H, ¹³C and ¹¹⁹Sn) spectra, TGA, and X-ray crystallography. The X-ray reveals that complexes 1–3 are 1D infinite double-chain polymers. The molecular of complex 1 is further linked by intermolecular C–H···O interactions to form a 2D network polymer. Complex 3 is linked by C–H···O interactions to form a 3D organotin framework.     

Synthesis,Crystal Structures,Luminescence, Biological and Catalytic Properties of Two d10 Metal-Organic Coordination Polymers Constructed from Mixed Ligands

Two d¹⁰ metal-organic coordination polymers, [Cd₂(4-cpa)₄(bmip)₂]_n (1) and [Zn(4-cpa)₂(4,4′-bpy)]_n (2), [4-cpa = 4-chlorophenylacetate, bmip = 1,3-bis(2-methylimidazoly)propane, 4,4′-bpy = 4,4′-bipyridine], were hydrothermally synthesized and characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis (TGA), powder X-ray diffraction and single-crystal X-ray diffraction. Single-crystal X-ray diffraction studies indicated that both 1 and 2 display analogous wave-like infinite chain structures. The two coordination polymers are further extended into 3D supramolecular structures through π···π stacking interactions and C–H···O hydrogen bonds for 1 and π···π stacking interactions, C–H···π stacking interactions and C–H···O hydrogen bonds for 2. Both 1 and 2 emit the intense blue luminescence at room temperature. The 4-Hcpa ligand and complexes 1 and 2 have been screened for their herbicidal activities against Brassica napus L. and Echinochloa crusgalli L. The results are compared with the activity of quizalofop-P-ethyl. Both compounds exhibit high catalytic properties on degradation of methyl orange in Fenton-like process.     

Structural Variations in Coordination Polymers of Sodium and Cesium Dicarboxylates

The coordination polymer {[Na₂L(μ-H₂O)(H₂O)₃]·H₂O} _n (1) derived from 2,2′-(phenylmethylidene-bis(3,5-methyl-2-phenyleneoxy)] diacetic acid (H₂ L) has repeat units comprising of hexa-coordinate diaqua-bridged dinuclear sodium complex ions. These units are connected through intervening mononuclear complex parts having penta-coordinated sodium ions. The sodium ions adopt repeated hexameric chair-like arrangement in the polymer. The cesium salt of H₂ L namely [Cs(HL)(μ-H₂O)(H₂O)] _n (2) is a coordination polymer. In this case one acid group of the ligand is deprotonated and 2 form self-assembly by intermolecular hydrogen bonds between the free carboxylic acid groups. The fluoro-substituted ligand 2,2′-(2-fluorophenylmethyledene-bis(3,5-methyl-2-phenyleneoxy)] diacetic acid (H ₂ L _f ) forms disodium salt with a composition [{Na₂L_f(μ-H₂O)(H₂O)₃}·H₂O] _n (3); which is a two dimensional coordination polymer. On the other hand the corresponding cesium salt of H ₂ L _f has a composition [{(H₂O)Cs(μ-H₂O)(μ-L_f)Cs(H₂O)₂}] (4); which is also a 2-D coordination polymer. The cesium ions are six or nine coordinate in the polymer and the coordination polymer possesses unusual Cs···F–C coordination bond.     

Synthesis, Crystal Structures and Luminescent Properties of pH-Dependent Zn (II) Coordination Polymers

Two new coordination polymers [Zn(L)(bib)] _n (1) and [Zn(L)(bib)_0.5] _n (2) [L = 5-hydroxyisophthalic acid and bib = 1,4-bis(2-methyl-imidazol-1-yl)butane] have been synthesized and characterized. X-ray single crystal diffractions show that complex 1 is a 2D layered structure and complex 2 is a 3D 6-connected topological net. Complex 1 are further assembled into a 3D supramolecular structure by intermolecular hydrogen bonding. Complex 2 features a two-fold interpenetrated pcu topology. Moreover, the fluorescent properties of complexes 1 and 2 were studied in the solid state at room temperature.