Syntheses and structures of three coordination polymers based on 4-methylbenzenethiolates of Zn(II) and Cd(II) and bipyridine

Using 4-methylbenzenethiolates of Zn or Cd as precursors and 4,4′-bipyridine (4,4′-bpy) as bridges, we have synthesized three new Zn(II)/Cd(II) coordination polymers, {[Cd(4,4′-bpy)₂(NCS)₂] · 2(SC₆H₄CH₃-4)₂} _n (1), {[Zn(4,4′-bpy)(SC₆H₄CH₃-4)₂] · DMF} _n (2) and {[Zn(4,4′-bpy)(SC₆H₄CH₃-4)₂] · H₂O · 0.5CH₃OH} _n (3). Compound 1 is a 2-D sheet-like square polymer in which four 4,4′-bpy ligands and two isothiocyanate ligands complete the octahedral Cd(II) coordination sphere. Compounds 2 and 3 have similar coordination around Zn(II), but have different polymer structures. In 2, Zn(II) centers are linked via a bidentate 4,4′-bipyridine to form 1-D twisted arched chains, which is a new structural type for Zn(II). Compound 3 has 1-D zigzag chains. The 2-D sheets in 1 and 1-D chains in 2 and 3 are assembled via intermolecular C–H ··· π and C–H ··· S interactions into 3-D supramolecular networks. C–H ··· S interactions are a vital factor in constructing the sulfur-containing coordination polymers. Different coordination modes and packing schemes in 1–3 show that the guest molecule has a critical influence on formation of polymers.     

Silver(I) 3-D-supramolecular coordination frameworks constructed by the combination of coordination bonds and supramolecular interactions

Room temperature reactions of the ternary adducts of AgNO₃, bipodal ligand [4,4′-bipyridine (4,4′-bpy) or trans-1,2-bis(4-pyridyl)ethylene (tbpe) or 1,2-bis(4-pyridyl)ethane (bpe)] and organic ligand [4-aminobenzoic acid (4-aba) or 4-hydroxybenzoic acid (4-hba) or terephthalate ion (tph)] afford new 3-D supramolecular coordination polymers (SCPs), namely, {[Ag(4,4′-bpy) · H₂O](4-ab) · 2H₂O} (1), {[Ag(tbpe)]0.5(4-hb) · 3H₂O} (2), [Ag₂(L)₂ · (tph)] (L = 4,4′-bpy, tbpe) (3,4) and {[Ag₂(bpe)₂ · (tph)] · 2H₂O} (5). The bipodal ligand coordinates to silver forming a 1-D cationic chain (A), while the organic ligand and solvent form a 1-D anionic chain (B) via hydrogen bonds. The chains construct layers which are connected via hydrogen bonds and π–π stacking forming a 3-D network structure. The presence of the carboxylate, amino and hydroxyl groups in the organic ligands significantly extend the dimensionality via hydrogen bonds. All the SCPs 1–5 exhibit strong luminescence.     

Syntheses,structures, and properties of supramolecular complexes with bipyridine and amino-Schiff-base derived from salicylaldehyde with glycine

The reactions of stoichiometric amounts of Cu(CH₃COO)₂ · 2H₂O or Ni(CH₃COO)₂ · 2H₂O with KHL (potassium salt of salicylideneglycine) and 4,4′-bipy or 2,2′-bipy ethanol afforded [Cu₂(L)₂(μ-4,4′-bipy)(4,4′-bipy)₂] · 2H₂O (1) (L = salicylideneglycine) and Ni(OAc)₂(2,2′-bipy) (H₂O)₂ (2), respectively. The structure of 1 contains two Cu(II)'s, bridged by 4,4′-bipy; each copper is square pyramidal. Complex 2 contains a Ni(II) in highly distorted octahedral geometry. The two complexes were constructed into 3-D interwoven networks by typical H-bonding (i.e., O?H ··· O and N?H ··· O) and some other intra- or intermolecular weak interactions (i.e., C?H ··· O).     

Ligand concentration-dependent supramolecular complexes with uncoordinated carbonyl groups based on a new pyrazole carboxylic acid ligand

One new pyrazole-based ligand, 1-carboxymethyl-3,5-dimethyl-1H-pyrazole-4-carboxylic acid (H₂cmdpca), has been synthesized and characterized. Structural analysis reveals that H₂cmdpca crystallizes in the monoclinic system and adopts a 3-D supramolecular network via the interaction of intermolecular hydrogen bonds. The reactions of Cd(II) ions with H₂cmdpca and 4,4′-bipyridine (4,4′-bpy) afforded three metal complexes, [Cd(4,4′-bpy)(Hcmdpca)₂(H₂O)₃]·H₂O (1), [Cd(4,4′-bpy)(Hcmdpca)₂(H₂O)]·3H₂O (2), and [Cd(4,4′-bpy)(Hcmdpca)₂(H₂O)] (3). Structural analyses reveal that these complexes are all monoclinic and 1, 2, and 3 exhibit mononuclear, 1-D chain, and 1-D with binuclear loop structures, respectively, which are further assembled into 3-D supramolecular frameworks through non-covalent interactions. 1 and 2 are true supramolecular isomers, while 2 and 3 are “pseudo-supramolecular” isomers. In addition, the thermal stability and luminescent properties of the complexes are also investigated.     

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 and crystal structures of 3D supramolecular compounds: [ M (4,4′-bipy)2(H2O)4] · (4,4′-bipy)2 · (3,5-daba)2 · 8H2O ( M =Zn,Mn)

Two new supramolecular compounds [M(4,4′-bipy)₂ (H₂O)₄] ·?(4,4′-bipy)₂ ·?(3,5-daba)₂ ·?8H₂O (M=Zn(1) or Mn(2), 4,4′-bipy =?4,4′-bipyridine, 3,5-daba =?3,5-diaminobenzoic acid anion) were synthesized and characterized by elemental analysis and X-ray crystal diffraction. In [M(4,4′-bipy)₂(H₂O)₄]²⁺, the M(II) is coordinated by two nitrogen atoms from two 4,4′-bipy molecules and four oxygen atoms from four waters to form an octahedral configuration. There exist uncoordinated 4,4′-bipy molecules, 3,5-diaminobenzolate counterions and water guests in the compounds. The 3D structures of the title supramolecular compounds are constructed by rich hydrogen bonds among [M(4,4′-bipy)₂(H₂O)₄]²⁺, uncoordinated 4,4′-bipy molecules, water molecules and 3,5-daba, containing a diverting hexa-member water ring.     

Synthesis,characterization and property study of new coordination polymers constructed from flexible dicarboxylates and bidentate nitrogen mixed ligands

Five new coordination polymers, [Cd(1,2′-cy)_0.5(bix)H₂O]_n (1), [Cd₂(1,2′-cy)₂(1,10′-phen)₂(H₂O)₂] (2), {[Co(1,2-cy)(2,2′-bipy)(H₂O)₂]·2H₂O}_n (3) {[Cd(succ)(1,10′-phen)H₂O]·H₂O}_n (4), and {[Cd(succ)(2,2′-bipy)H₂O]·2H₂O}_n (5) (1,2-cy = 4-cyclohexene-1,2-dicarboxylate, succ = succinic acid, bix = 1,4-bis(imidazol-1-ylmethyl)benzene, 1,10′-phen = 1,10-phenanthroline, 2,2′-bipy = 2,2′-bipyridine), have been synthesized and characterized by single-crystallographic X-ray diffraction. Complex 1 shows a two-dimensional covalent layer structure. Complex 2 exhibits a two-dimensional supramolecular layer network composed from discrete fundamental units. Complex 3 exhibits a one-dimensional covalent chain-like structure, which further extends to a two-dimensional supramolecular structure with hydrogen bonding and π-π interactions respectively. Complexes 4 and 5 show three-dimensional supramolecular networks composed from one-dimensional chain-like covalent structures. Furthermore, the magnetic property of complex 3 and fluorescent properties of complexes 1, 2, 4 and 5 have also been studied.     

Synthesis,structure, and properties of trinuclear pivalate {Zn2Eu} complexes with N-donor ligands

New luminescent heterometallic complexes of Eu³⁺ and Zn²⁺ were synthesized: Zn₂Eu(NO₃)(Piv)₆(L)₂ (Piv is pivalate anion, L = MeCN (1), 2,3-lutidine (2), 2,2′-bpy (3)) and [Zn₂(Piv)₃(2,2′-bpy)₂][ZnEu(NO₃)₃(Piv)₃(2,2′-bpy)] (4). In the case of 2,2′-bpy, the order of mixing of the reagents ([Zn(Piv)₂] _n , Eu(NO₃)₃·6H₂O, and 2,2′-bpy) affects the composition of the final reaction product: the reaction of [Zn(Piv)₂] _n and Eu(NO₃)₃·6H₂O (in the ratio Zn : Eu = 3 : 1) in MeCN affords complex 1 and the subsequent addition of 2,2′-bpy (Zn : L = 1 : 1) affords complex 3. Complex 4 is formed in the reaction of [Zn(Piv)₂] _n and 2,2′-bpy (Zn : L = 1 : 1) in MeCN followed by the addition of Eu(NO₃)₃·6H₂O (Zn : Eu = 3 : 1). The luminescence spectra of compounds 1–4 (Zn : Eu = 3 : 1) exhibit metal-centered luminescence of Eu³⁺. The most efficient ligand-antenna is 2,2′-bpy, which is due to the optimum position of the triplet level of this ligand.     

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.     

Two- and three-dimensional photoluminescent Cd(II)-carboxylate coordination frameworks bridged by benzenepentacarboxylate and N-donor ligands

Reactions of Cd(OAc)₂·H₂O, benzenepentacarboxylic acid (H₅bpc), 2,2′-bpy/4,4′-bpy, and Et₃N yield two new coordination polymers [Cd₅(bpc)₂(2,2′-bpy)₄(H₂O)₄] (1) and [Cd₅(bpc)₂(4,4′-bpy)₂(H₂O)₄]·3H₂O (2). Complex 1 is a 2-D structure based on six-connected Cd-carboxylate layers. Adjacent layers are linked by π–π interactions and hydrogen bonds to generate a layered supramolecular network. Complex 2 is a 3-D coordination framework. The bpc ligands adopting μ ₇-bridging mode connect Cd(II) ions to form a 3-D open framework with elliptic channels, in which the coordinated 4,4′-bpy ligands fill to support the whole framework. Complex 2 exhibits strong photoluminescence at room temperature.     

New nano-particle La(III) supramolecular compound as a precursor for preparation of lanthanum oxybromide-, hydroxide-, and oxide-nanostructures

Nano-particles of a new La(III) supramolecular compound [La(4,4′-bipy)(H₂O)₂(NO₃)_3.75Br_0.25] · (4,4′-Hbipy) (1), have been synthesized from reaction of 4,4′-bipy with La(NO₃)₃ and NaBr by the sonochemical method. For the first time LaOBr, La(OH)₃ and La₂O₃ nano-structures were prepared from [La(4,4′-bipy)(H₂O)₂(NO₃)_3.75Br_0.25] · (4,4′-Hbipy) (1) by calcination at 400, 500, and 700°C, respectively. The structure of 1 was determined by X-ray crystallography and the nano-structures were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). Thermal stabilities of nano and crystal samples of 1 were studied and compared with each other.     

Supramolecular networks constructed by cationic copper(II) complexes incorporating hybrid water–anionic polymeric assemblies

Two complexes, [Cu₂(TFSA)(2,2′-bpy)₄]?·?TFSA?·?8H₂O (1) and {[Cu(4,4′-bpy)(H₂O)₂]?·?TFSA?·?6H₂O} _n (2) (H₂TFSA?=?tetrafluorosuccinic acid, 2,2′-bpy?=?2,2′-bipyridine, and 4,4′-bpy?=?4,4′-bipyridine), have been synthesized and structurally characterized by X-ray structural analyses. Complex 1 is a binuclear molecule bridged by TFSA ligands; 2 is a 1-D chain bridged by 4,4′-bpy ligands. The asymmetric units of the two complexes are composed of cationic complexes [Cu₂(TFSA)(2,2′-bpy)₄]²⁺ (1) and [Cu(4,4′-bpy)(H₂O)₂]²⁺ (2), free TFSA anion, and independent crystallization water molecules. A unique 2-D hybrid water–TFSA anionic layer by linkage of {[(H₂O)₈(TFSA)]^2?} _n fragments consisting of 1-D T6(0)A2 water tape and TFSA anionic units by hydrogen bonds in 1 was observed. Unique 2-D hybrid water–TFSA anionic layer generated by the linkage of {[(H₂O)₆(TFSA)]^2?} _n fragments consisting of cyclic water tetramers with appended water molecules and TFSA anionic units, and 1-D metal–water tape [Cu–H₂O?···?(H₂O)₆?···?H₂O^?] _n in 2 were found. 3-D supramolecular networks of the two complexes consist of cationic complexes and water–TFSA anionic assemblies connected by hydrogen bonds.     

Two cadmium(II) addition compounds with 3-hydroxy-2,7-naphthalenedisulfonate containing aromatic diamines and their 3-D net

{[CdCl(2,2′-bipy)₂(H₂O)]⁺·[Cd(3-O^?-2,7-NDS)(2,2′-bipy)₂]^?·3H₂O} (1) and {[Cd(phen)₃]²⁺·2[Cd(3-O^?-2,7-NDS)(phen)₂]^?·8.5H₂O} (2) (3-OH-2,7-NDS?=?3-hydroxy-2,7-naphthalenedisulfonate, phen?=?1,10-phenanthroline, and 2,2′-bipy?=?2,2′-bipydine) were prepared and characterized by X-ray single-crystal diffraction. Compound 1 contains a discrete coordination cation [CdCl(2,2′-bipy)₂(H₂O)]⁺ and a coordination anion [Cd(3-O^?-2,7-NDS)(2,2′-bipy)₂]^?; 2 contains a discrete coordination cation [Cd(phen)₃]²⁺ and two coordination anions [Cd(3-O^?-2,7-NDS)(phen)₂]^?. There are numerous weak interactions among the coordination cation, coordination anion, and free water molecules, such as O–H?···?O hydrogen bonds, π?···?π stacking, and Cl^??···?π interactions in 1 and π?···?π stacking and C–H?···?π interactions in 2. The cations and anions as building blocks are connected to construct different 3-D supramolecular architectures via weak intermolecular interactions. Particularly, the capsule structure of 1 was observed.     

Five metal imidazole dicarboxylate-based compounds comprising M3(MIDC)2 entities (M = Zn2+, Co2+, Mn2+): syntheses,structures and properties

Five metal imidazole dicarboxylate-based compounds, {[Zn₃(MIDC)₂(4,4′-bipy)₃](4,4′-bipy)·8H₂O}_n (1), {[Co₃(MIDC)₂(4,4′-bipy)₃](4,4′-bipy)·6H₂O}_n (2), {[Co₃(MIDC)₂(py)₂(H₂O)₂]}_n (3), {[Mn₆(MIDC)₄(py)₅(H₂O)₄]}_n (4), and {[Mn₃(MIDC)₂(Phen)₃(H₂O)₂]}_n (5) (H₃MIDC = 2-methyl-1H-imidazole-4,5-dicarboxylic acid; 4,4′-bipy = 4,4′-bipyridine; py = pyridine; Phen = 1,10-phenanthroline), have been synthesized under hydrothermal conditions and characterized by elemental analyses, IR spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction. We control the coordination modes of H₃MIDC via hydrazine and obtained a series of coordination compounds containing honeycomb-like [M₃(MIDC)₂]_n layers. We also investigated the effects of different neutral terminal or bridging ligands on [M₃(MIDC)₂]_n layers. Coplanar [M₃(MIDC)₂]_n layers and 4,4-bipy were used to construct 3-D frameworks of 1 and 2. Puckered [M₃(MIDC)₂]_n layers were found in 3–5; 4 is the first [M₃(L)₂]_n layer structure with two crests and troughs during each period (L = imidazole-4,5-dicarboxylic acid or its analog). Compound 5 is the first puckered [M₃(L)₂]_n layer structure decorated by chelating neutral ligands. Compound 1 exhibits weak blue photoluminescence in the solid state at room temperature. Variable-temperature magnetic susceptibility measurements of 2–5 indicate strong antiferromagnetic interactions.     

A novel one-dimensional copper(II) imino nitroxide polymer

A copper(II) complex [Cu(im2-py)(4,4′-bipy)(NO₃)](NO₃)·1.5H₂O (im2-py?=?2-(2′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl; 4,4′-bipy?=?4,4′-bipyridyl) has been synthesized by reaction of Cu(NO₃)·3H₂O with im2py and 4,4-bipyridyl in methanol solution. Its crystal structure has been determined by X-ray diffraction. The structure shows that each copper ion is coordinated by a bidentate imino nitroxide radical, two 4,4′-bipyridyl ligands and a nitrate group to form a distorted square pyramidal environment. The crystal structure consists of chains of copper ions linked by 4,4′-bipyridyl.     

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.     

Two transition metal supramolecular compounds based on 2-(4-isopropylbenzoyl)benzoic acid: syntheses,crystal structures,and luminescent properties

Two new supramolecular compounds, [Zn₂(L)₃(4,4′-bpy)(OH)]_n (1) and [Cd(L)₂(2,2′-bpy)(H₂O)]·2H₂O (2) (HL?=?2-(4-isopropylbenzoyl)benzoic acid, 4,4′-bpy?=?4,4′-bipyridine, 2,2′-bpy?=?2,2′-bipyridine), have been hydrothermally synthesized and characterized by elemental analysis, infra-red spectroscopy, thermal gravimetric analyzes, and single-crystal X-ray diffraction. 1 exhibits 1-D chain and 2 is 0-D mononuclear. They are both linked into 2-D supramolecular layers by non-covalent interactions. Luminescence properties were also investigated.     

Three rare heteromultinuclear 3d-4f salamo-like complexes constructed from auxiliary ligand 4,4′-bipy: Syntheses,structural characterizations,fluorescence and antimicobial properties

Three rare heteromultinuclear complexes, _∞[NiL(4,4′-bipy)Pr (NO₃)₃]·(CH₃)₂CHOH ( 1 ), [{CuLSm (NO₃)₃}₂(4,4′-bipy)]·CH₃OH ( 2 ) and [{CuL (CH₃CH₂OH)Eu (NO₃)₃] ( 3 ) with a symmetrical salamo-like hexadentate ligand H₂L have been synthesized, and characterized by FT-IR, UV–vis and X-ray crystallography. Complex 1 is a 1D coordination polymer constructed from heterobimetallic [Ni(L)Pr (NO₃)₃] units which are connected by the exo-dentate ligand 4,4′-bipy bearing nitrogen-donor atoms. Complex 2 is a heterotetranuclear dimer based on [Cu(L)Sm (NO₃)₃] moieties which are linked through the exo-dentate 4,4′-bipy hasing nitrogen-donor atoms. Complex 3 is a heterodinuclear structure, Cu (II) atom is five-coordinate possessing a distorted square pyramidal geometry, and Eu (III) atom is a deca-coordinate adopting a distorted bicapped square antiprism. In addition, fluorescence and antimicobial properties of the ligand H₂L and its complexes 1 – 3 have also been discussed.     

Two new Pb(II) coordination polymers, [Pb2(μ-4,4′-bipy) (μ-2-sb)2(DMF)] n and {[Pb2(μ-4,4′-bipy) (μ-2-sb)2(H2O)2] · H2O} n (4,4′-bipy = 4,4′-bipyridine and 2-H2sb = 2-sufobenzoic acid)

Two new 2D Pb₂(μ-4,4′-bipy)(μ-2-sb)₂ coordination polymers, [Pb₂(μ-4,4′-bipy)(μ-2-sb)₂(DMF)] _n (1) and {[Pb₂(μ-4,4′-bipy)(μ-2-sb)₂(H₂O)₂] · H₂O} _n (2), have been synthesized, characterized and studied by X-ray crystallography. The structural studies show the Pb atoms to have seven- and eight-coordinate holodirected geometries.     

A new ZnII two-dimensional coordination polymer, {[Zn(μ-4,4′-bipy)(1,4-ndc)(H2O)2] · (H2O)} n (4,4′-bipy= 4,4′-bipyridine and 1,4-ndc=1,4-naphthalenedicarboxylate)

A 2D Zn^II(μ-4,4′-bipy) coordination polymer with 1,4-naphthalenedicarboxylate, {[Zn(μ-4,4′-bipy)(1,4-ndc)(H₂O)₂] · (H₂O)} _n , has been synthesized, characterized and studied by X-ray crystallography. The structural studies show the Zn atoms have six-coordinate geometry with a distorted octahedral environment. The 2D structure is grown by hydrogen bonds into a hybrid three-dimensional network.