pH-controlled the formation of 4-sulfocalix[4]arene-based 1D and 2D coordination polymers

Three manganese/4-sulfocalix[4]arene complexes, namely, {H[(C₂₈H₂₀O₁₆S₄)Mn(H₂O)₄Mn_0.5(H₂O)₂]}_n ·6nH₂O (1), {NH₄[(C₂₈H₂₀O₁₆S₄)Mn(H₂O)₄Mn_0.5(H₂O)₂]}_n · 5nH₂O (2), [(C₂₈H₂₀O₁₆S₄)Mn₂(H₂O)₈]_n · 6nH₂O (3), have been synthesized under different pH conditions. Complex 1, which exhibits a one-dimensional (1D) structure, is formed at [H⁺] = 2.0 mol L⁻¹. Reaction at pH 4 leads to another one-dimensional (1D) coordination polymer of 2. At pH 5, a two-dimensional (2D) coordination polymer of complex 3 is formed, showing clearly structural effects on pH response.     

A palladium(II) complex of 4′-(4-pyridyl)-2,2′:6′,2″-terpyridine: Lattice control through an interplay of stacking and hydrogen bonding effects

The complex [Pd(1)Cl]Cl where 1 =  4′-(4-pyridyl)-2,2′:6′,2″-terpyridine is reported. The single crystal structure of [Pd(1)Cl]Cl · 3H₂O · DMF features rows of columns of [Pd(1)Cl]⁺ cations which are supported by Pd⋯Pd interactions (3.367(1) and 3.440(1) Å) and separated by hydrogen-bonded 4.8² nets of water molecules and Cl⁻ ions.     

A novel 3D silver(I) coordination polymer exhibiting unprecedented μ3- and μ4-bonding modes of 2-aminopyrazines

The unprecedented μ₃- and μ₄-bonding modes of NH₂pyz (NH₂pyz = 2-aminopyrazine) are observed for the first time in a novel 3D Ag(I) coordination polymer [Ag₇(NHpyz)₆(ClO₄)]_n (1) which was obtained by reaction of Ag₂O, NH₂pyz and NaClO₄ in H₂O/CH₃OH/NH₃ media under ultrasonic treatment. Compound 1 is a 3D framework with infinite 1D Ag belts incorporating diverse Ag···Ag interactions. Moreover, 1 exhibits photoluminescence maximized at 494 nm upon 300 nm excitation at room temperature, which may be mainly assigned to ligand-to-metal charge transfer (LMCT) mixed with metal-centered (d-s/d-p) transitions. Semiconducting behavior of 1 was also measured at room temperature with σ value of 6.78 × 10^?6 S cm^?1.     

Novel 3-dimensional sixfold interpenetrating diamondoid networks of copper(I) coordination polymers of polypyridyl ligands – Syntheses,characterization and crystal structures

Two new coordination polymers [Cu(L¹)₂]_n(ClO₄)_n·2nH₂O (1), [Cu(L²)₂]_n(ClO₄)_n·2nH₂O (2) of polydentate imine/pyridyl ligands, L¹ and L² with Cu(I) ion have been synthesized and characterized by single crystal X-ray diffraction studies, elemental analyses, IR′ UV–vis and NMR spectroscopy. They represent 3-dimensional, sixfold interpenetrating diamondoid network structures having large pores of dimension, 35 × 21 Å² in 1 and 38 × 19 Å² in 2, respectively.     

Two corrugated 2D bilayer (63)(658) topological coordination polymers: Synthesis,structure, and water-induced reversible transformation

Two stable supramolecular microporous polymers with double-layer structures, [Co(AIP)(BPY)_0.5 · H₂O]_n · 2nH₂O (1) and [Ni(AIP)(BPY)_0.5 · H₂O]_n · 2nH₂O (2), were constructed from AIP (5-aminoisophthalate) and BPY (4,4′-bipyridine) under hydrothermal conditions. Both of them exhibit rarely reported (3,4)-connected (6³)(6⁵8) topology and interesting water-induced reversible transformation properties that are confirmed by PXRD studies.     

Structural characterization of ferromagnetic bridged-acetato and -dichlorido copper(II) complexes based on bicompartmental 4-t-butylphenol

The reaction of Cu(II) salts with 2,6-bis[bis(2-pyridylmethyl)aminomethyl]-4-t-butylphenol (L^t-Bu-OH) afforded two bridged-phenoxido/hydroxido complexes. The dinuclear bridged acetate species [Cu₂(μ-L^t-Bu-O)(μ-CH₃COO)](PF₆)₂ (1) and the 1D polymeric doubly-bridged-chlorido {[Cu₂(μ-L^t-Bu-OH)(μ-Cl)₂](ClO₄)₂·4H₂O}_n (2). The two complexes were structurally characterized. Both complexes revealed ferromagnetic interactions; moderate in complex 1 (J = + 30.8 cm^− 1) and very weak (J = + 2.25 cm⁻¹) in 2.     

Spectroscopic studies on bis(1-amidino-O-alkylurea) copper(II) sulfate complexes where alkyl = methyl,ethyl, n-propyl or n-butyl: EPR evidence for binuclear complexes

Four new Cu(II) Complexes viz. [Cu(II)(1-amidino-O-methylurea)₂]SO₄·2H₂O (1), [Cu(II)(1-amidino-O-ethylurea)₂](SO₄)₂·2H₂O (2), [Cu(II)(1-amidino-O-n-propylurea)₂] SO₄·2H₂O (3), [Cu(II)(1-amidino-O-n-butylurea)₂]₂(SO₄)₂·2H₂O (4) have been synthesized and characterized. EPR spectrum of complex 4 at RT consisted of fine-structure transitions (ΔMs = ±1) with zero-field splitting (ZFS) of 0.0485 cm^?1 and a half-field signal (ΔMs = ±2) at ca. 1600 G, revealed formation of binuclear complex (S = 1). Whereas EPR spectrum of complex 2 in DMSO showed a mixture of mononuclear and binuclear complex in the ratio 0.75:1.0 with ZFS of 0.0385 cm^?1. From the temperature dependence of the EPR signal intensity, the isotropic exchange-interaction constant J was evaluated.     

Three Ag(I)–cyanide coordination polymers with metal bonds tuned by N-heterocyclic ligands

Hydrothermal reactions of AgNO₃, K₃[Fe(CN)₆] with N-heterocyclic ligands afforded three novel Ag(I)–cyanide coordination polymers, [Ag₂(CN)₂(tpt)]_n (1), {[Ag(CN)(bpe)_0.5][Ag(CN)]}_n (2) and [Ag(CN)(btmb)_0.5]_n (3) (tpt = 2,4,6-tris(4-pyridyl)-1,3,5-triazine, bpe = 1,2-bis(4-pyridyl)ethane, btmb = 1,2-bis(1,2,4-triazol-1-ylmethyl)benzene). In complex 1, two Ag(CN) linear chains are bridged by bidentate tpt ligand to form a ladder-like structure, which are further connected by AgAg metal bond to generate a 2D polymeric network. Complex 2 is an interesting 3D supramolecular architecture assembled by 2D [Ag¹(CN)(bpe)_0.5]_n network and linear [Ag²(CN)]_n chain combined by strong AgAg metal bond. Complex 3 is a 1D ladder-like double-chain polymer constructed from Ag–cyanide linear chains and btmb spacer, which is further extended to a 2D supramolecular network by Ag–Ag weak interaction. The Ag–Ag metal interactions play important roles in the construction of three coordination polymers. Complexes 1 and 2 are respectively thermally stable at 300 and 180 °C. Complexes 1 and 3 emit strong blue luminescence.     

A rare (3, 6, 10)-connected net containing both Zn2(COO)4 and Zn4(COO)8 units

A novel coordination polymer [Zn₃(btrc)₂(L1)]_n (1) (H₃btrc = 1, 2, 4-benzenetricarboxylic acid; L1 = 1, 3-bis(4-pyridyl)propane) has been synthesized under hydrothermal conditions. Single crystal X-ray diffraction study reveals that polymer 1 presents an unusual example of (3, 6, 10)-connected net with (4·6·7) (5²·6⁶·7⁷) (4¹⁶·5¹²·6⁴·7¹³) topology symbol, where btrc^3?, Zn₂(CO₂)₄, and Zn₄(CO₂)₈ units act as three-, six-, and ten-connecting nodes, respectively. In addition, the IR spectra, luminescence properties and thermogravimetric analysis of this polymer are investigated in this study.     

Two 2-D 4-connected lanthanide coordination framework based on benzimidazole-5,6-dicarboxylate and acetate mixed ligands

Two 2-D polymers, [Ln(bidc)(Ac)·H₂O]_n (Ln = Tb(1), Dy(2) H₂bidc = benzimidazole-5,6-dicarboxylic acid, HAc = acetic acid), have been successfully synthesized under hydrothermal conditions at 150 °C and characterized by elemental analysis, infrared spectra and single-crystal X-ray diffraction. Single crystal X-ray diffraction analyses reveal that the two compounds are isomorphous and exhibit one new (4,4)-connected 2-nodal (4⁴·6²)(4⁴·6²) layer-like net, stabilized by the interchain hydrogen bonding N–H?O, O–H?O and π?π stacking interactions between two benzimidazole rings. 2-D layers are further connected by the interlayer O–H?O hydrogen-bonding interactions to form a 3-D supermoleculaer network. Moreover, the luminescent property of compound 1 and thermogravimetric analyses of the two complexes 1–2 are discussed in detail.     

Novel silver(I) compounds assembled from hybrid ligands based on linear or T-shaped coordination environment

Two novel 1D compounds {[Ag₃(Hbptc)(bpa)₂]·H₂O}_n (1) and [Ag₂(H₂bptc)(bpp)₂]_n (2) (H₄bptc = 3,3′,4,4′-benzophenonetetracarboxylic acid, bpa = 1,2-bis(4-pyridyl)ethane and bpp = 1,3-bis(4-pyridyl)propane) were synthesized and structurally characterized. The crystal structures of compounds exhibit two kinds of ladder-like chains based on linear or T-shaped coordination environment of Ag(I). Fluorescence spectra of compounds 1 and 2 indicate the unusual intensity of fluorescent emission upon photoexcitation which may be attributed to ligand-to-metal charge transfer and Ag–Ag interactions.     

Syntheses,structures and luminescent properties of two new two-fold interpenetrating 2D coordination polymers based on 4′-(4-carboxyphenyl)-4,2′:6′,4″-terpyridine

Two new coordination polymers, [Zn₂(cptpy)₂Cl₂]_n·0.5nH₂O (1) and [Cd₂(cptpy)₄]_n·3.5nH₂O (2) (Hcptpy = 4′-(4-carboxyphenyl)-4,2′:6′,4″-terpyridine), were synthesized under hydrothermal conditions and characterized by elemental analysis, IR and single crystal X-ray diffraction. Compound 1 shows a new two-fold interpenetrating 3-connected 2D framework with the hcb topological net and the Schläfli symbol of 6³. Compound 2 displays a two-fold interpenetrating (4,4)-connected 2D framework with the sql topological net and the Schläfli symbol of {4⁴ · 6²}. Interestingly, compounds 1 and 2 were obtained in the similar reaction conditions. The structural diversity of compounds 1 and 2 may illustrate the marked effect of the metal ion of the reaction solution. Additionally, photoluminescence properties of compounds 1–2 have been investigated.     

Construction of two mercury(II) coordination frameworks involving in situ tetrazole ligand synthesis

Two novel mercury(II)-organic polymeric complexes [HgCl(pzta)]_n (1) and [Hg₃Cl₂(pzta)₄(H₂O)₂]_n (2) [pzta = pyrazinyl tetrazolate] were obtained by in situ synthesis of pyrazinyl tetrazolate from the reaction of pyrazinecarbonitrile with sodium azide in the presence of mercury(II) salts. Complex 1 is a 3D coordination polymer with a 3,5-connected hms [(6³)(6⁹ · 8)] net consisting of mildly undulate (6, 3) sheets and bridging chlorine ligands; while complex 2 is also a 3D supramolecular network built from 2D layers with the 4-connected sql {4⁴ · 6²} net that are assembled via hydrogen bonds and π?π stacking interactions. Last but not least, photofluorescent properties of the two complexes have also been investigated.     

Conformational isomerism of a flexible fluorinated bis-pyridinecarboxamide ligand in the structural direction of two distinct layered CuII coordination polymers

Reaction of a flexible pyridinecarboxamide ligand N,N′-[(2,3,5,6-tetrafluoro-1,4-phenylene) bis(methylene)]bis(pyridine-4-carboxamide) (H₂tfpbbp) with Cu^II chloride or perchlorate affords two coordination polymers {[Cu(H₂tfpbbp)(tfpbbp)(H₂O)] · 2DMF · 4H₂O}_n (1) and {[Cu(H₂tfpbbp)₂(ClO₄)₂] · 3H₂O}_n (2). Both complexes have 2-D (4,4) layered networks extended by the exo-bidentate bridging ligands, which however consist of distinct [Cu–ligand]₄ meshes owing to the conformational difference of ligands. Their spectroscopic, thermal, and fluorescence properties have also been investigated.     

Three d10 coordination polymers based on rigid ligands with flexible functional groups: Syntheses,structures and luminescence

Three coordination polymers, namely, {[Zn(L)(BPY)]·DMF·H₂O}_n (1), {[Zn(L)(TPY)]·0.5H₂BDC·H₂O}_n (2), {[Cd(L)(H₂O)₂]·DMF}_n (3), have been synthesized based on a rigid linear carboxylate ligand (H₂L = 2′,5′-dimethoxy-[1,1′:4′,1″-terphenyl]-4,4″-dicarboxylic acid) and different lengths of pyridine ligands (TPY = 4,3′:5′,4″-terpyridine; BPY = 4,4′-bipyridine). These complexes have been characterized by single crystal X-ray diffraction, infrared spectroscopy, thermogravimetry, elemental analysis, and powder X-ray diffraction measurements. Complex 1 is a 6-connected 3-fold interpenetrating pcu net with point symbol {4¹² ∙ 6³}, 2 and 3 can be simplified as 4-connected sql nets with point symbol {4⁴ ∙ 6²}. In addition, their photoluminescent properties are also investigated in detail.     

One-dimensional nanoporous M2L2 rhombohedral molecular square with strong blue fluorescent emission

The hydrothermal reactions of Zn(ClO₄)₂ · 6H₂O and Cd(ClO₄)₂ · 6H₂O with the ligand N,N^′-bis(pyridylcarbonyl)-4,4^′-diaminodiphenyl ether (L) afford two one-dimensional (1D) coordination polymers, ([CdL(ClO₄)₂ · (H₂O)₂] · 2H₂O) (1) and [ZnL(ClO₄)₂ · (H₂O)₂] · 2H₂O, (2) having a nanoporous M₂L₂ rhombohedral molecular square with an approximately accessible cavity of 12.9 × 12.9 (1) and 12.7 × 12.7 (2) Å without any interpenetrations. Both 1 and 2 are isostructural and display very strong blue fluorescent emission in the solid state at room temperature.     

Syntheses,structures and luminescence of two cadmium entangled coordination polymers based on bis(imidazole) and biscarboxylate ligands

Two entangled coordination polymers [Cd₂(bib)(bdc)₂]_n (1) and [Cd₂(bib)(bda)₂]_n (2) were synthesized by the hydrothermal reaction (bib = 1,4-bis(2-methyl-imidazol-1-yl)butane, bdc = 1,2-benzenedicarboxylate, bda = 1,4-benzenediacetate). 1 exhibits an unusual 6-connected self-catenated 3D network based on Cd₂(COO)₂ dimer with the point symbol of (4⁴·6¹⁰·8). 2 exhibits a 3-fold interpenetrating 3D pcu network based on Cd₂(COO)₂ dimer. The different conformations of bib ligands (the anti–anti–anti conformation in 1 and gauche–anti–gauche conformation in 2) play the key role in the construction of different structures in 1 and 2. The luminescence and thermal stability were investigated.     

A lamella 2D silver(I) coordination polymer constructed from in situ generated 2-mercaptobenzoic acid

The reaction of Ag₂O and 2,2′-dithiodibenzoic acid (dtba) under ultrasonic condition gave rise to a novel metal–organic coordination polymer [Ag₄(2-mba)₂·(H₂O)₂]_n (1) (2-H₂mba = 2-mercaptobenzoic acid) involving in situ generated 2-mba ligand. Complex 1 shows a lamella 2D structure with a 6³-hcb net which is comprised of fused Ag₆ hexagonal rings. Moreover, 1 exhibits photoluminescence maximized at 468 nm upon 330 nm excitation at room temperature, which may be assigned to a ligand-to-metal charge transfer (LMCT) transition. Semiconducting behavior was also measured at room temperature with σ value of 3.24 × 10^?5 S cm^?1.     

An unprecedented (4, 8)-connected self-penetrating Cu(I)-MOF constructed from the rare [Cu4I2]2 + cationic cluster and in situ generated tetrazole ligand

The in situ hydrothermal reaction of CuI, NaN₃ and 4-(1H-imidazol-1-yl)benzonitrile leads to a new three-dimensional pillared-layer Cu(I)-MOF, [Cu₂(μ₃-I)(μ₅-IPT)]_n (1) (HIPT = 5-[4-(imidazol-1-yl)phenyl]tetrazolate). Interestingly, the structure of 1 exhibits an unprecedented binodal (4, 8)-connected three-dimensional self-penetrating framework first constructed from [Cu₄I₂]^2 + cationic clusters as 8-connected nodes and in situ generated IPT ligands as 4-connected nodes. Moreover, 1 is strongly luminescent with green emission (λ_em = 545 nm) in the solid-state.     

Self-assembly of novel supramolecular silver(I) compound based on mixed ligands bipy/TST3−, H3TST = 2,4,6-tris (4-sulfophenylamino)-1,3,5-triazine

The novel supramolecular silver(I) compound with formula [Ag₆(TST)₂(bipy)₆(H₂O)₂]_n · 3nH₂O (1) based on assembly of Ag(I) and mixed ligand bipy/TST³⁻, bipy = 2,2′-bipyridine, H₃TST = 2,4,6-tris(4-sulfophenylamino)-1,3,5-triazine, has been prepared by hydrothermal method. In the solid-state structure of 1, two-dimensional layered polymeric structures extended with subunits [Ag₆(TST)₂(bipy)₆(H₂O)₂] interact each other in the form of π–π attractions between bipy, forming a three-dimensional supramolecular architecture. Compound 1 represents a Ag-containing polymeric compound possessing room-temperature luminescence.