Multidentate N-donor Ligand Research Articles

Cobalt complexes with multi-dentate N-donor ligands: Redox, X-ray photoelectron spectroscopic and theoretical study

Five CoII complexes were prepared with different multi-dentate N-donor ligands (5-Nitro-1,10-phenanthroline, 1,10-phenanthroline, 2,2′:6′,2″-terpyridine, 2,2′-dipyridyl or 4,4′-dimethoxy-2,2′-bipyridine). Complexation was confirmed with the blue-shift of stretching frequency of the CN moiety of the ligands as measured by ATR FTIR and by XPS spectra. The average XPS binding energies (BE) of the main and satellite structures of Co 2p3/2 photoelectron lines for CoII were ca. 780.3 eV and 785.0 eV respectively. The diffusion controlled formal reduction potential E0′ of the CoII/III redox couple measured in aqueous medium ranged between 0.08 and 0.58 V versus NHE. Ihe CoII/I redox couple measured in DMF ranged between between −1.1 and −1.7 V vs HFc/HFc+. Directly proportional relationships were established between the E0′ of both the CoII/III and CoII/I redox couples and the BE of the main CoII 2p3/2 photoelectron lines and DFT calculated energies and charges. These relationships all illustrate the electronic influence of the different N-donor ligands on the effective charge of the central cobalt(II) ion the ligands are coordinated to, can be quantised by the different experimental redox and XPS BE values and DFT calculated electronic descriptors.

Two Ag(I)-Containing Supramolecular Coordination Polymers Constructed from the Multidentate N-donor Ligand 1-((1H-1,2,4-triazol-1-yl)methyl)-3,5-bis(3-pyridyl)-1,2,4-triazole Based on Hydrogen-Bonding and π–π Interactions: Syntheses, Crystal Structures, Optical Band Gaps and Luminescent Properties

Two Ag(I)-based coordination polymers, namely [Ag2(3,3′-tmbpt)(o-Hbdc)2]·H2O (1) and [Ag8(3,3′-tmbpt)4(1,2,4-Hbtc)4(H2O)] (2) (3,3′-tmbpt = 1-((1H-1,2,4-triazol-1-yl)methyl)-3,5-bis(3-pyridyl)-1,2,4-triazole, o-H2bdc = 1,2-benzenedicarboxylic acid and 1,2,4-H3btc = 1,2,4-benzenetricarboxylic acid), have been synthesized. Single-crystal X-ray diffraction analyses, elemental analyses, infrared spectra, powder X-ray diffraction analyses and thermogravimetric analyses have been carried out to characterize the structures of 1 and 2. Compound 1 shows a (3,4)-connected 2D layered structure with a Schlafli symbol of (42·6)(42·63·8). The intermolecular O–H···O hydrogen-bonding interactions extend the 2D layer into a 3D supramolecular architecture. Compound 2 exhibits a (3,3)-connected double-layered structure with a Schlafli symbol of (4·8·10)2(82·10)2. The intermolecular C–H···O hydrogen-bonding interactions link the double-layers to form a 3D supramolecular architecture. Moreover, there are intramolecular and intermolecular π–π interactions in 1 and 2, which stabilize the whole 3D supramolecular architectures. The band gaps of 1 and 2 are 3.19 and 3.09 eV, respectively, indicating the potential of 1 and 2 as semiconductive materials with wide band gaps. Moreover, 1 and 2 emit intense blue-green light, which may be potential photoactive materials. Two Ag(I)-based 3D supramolecular coordination polymers constructed from a multidentate N-donor ligand and two aromatic polycarboxylate anions via hydrogen-bonding and π–π interactions have been synthesized and characterized. The band gaps and photoluminescent properties of the compounds have been studied.

Syntheses, Crystal Structures, Characterization, Optical Band Gaps and Photoluminescence of Two Zn(II) Coordination Polymers

Two novel coordination polymers based on Zn(II) ions, 1-((1H-1,2,4-triazol-1-yl)methyl)-3-(4-pyridyl)-5-(3-pyridyl)-1,2,4-triazole (3,4′-tmbpt), and two aromatic polycarboxylate anions, namely [Zn(3,4′-tmbpt)(m-bdc)(H2O)]·H2O (1) and [Zn2(3,4′-tmbpt)(btc)(OH)] (2) (m-H2bdc = 1,3-benzenedicarboxylic acid and H3btc = 1,3,5-benzenetricarboxylic acid), have been synthesized. The structures of 1 and 2 have been characterized by single-crystal X-ray diffraction analyses, elemental analyses, infrared spectra, powder X-ray diffraction analyses and thermogravimetric analyses. Compound 1 shows a 2D layered structure, which is extended by the hydrogen bonding interactions to form a 3D supramolecular architecture. Compound 2 exhibits a 3D twofold interpenetrating framework with a Schlafli symbol of (63)(69·8). Diffuse reflection spectra of 1 and 2 indicate that the band gaps of 1 and 2 are 3.42 and 3.63 eV, respectively. The results indicate that compounds 1 and 2 may be potential semiconductive materials with wide band gaps. Moreover, 1 and 2 display intense blue-green emission and appear to be potential photoactive materials. Two new coordination polymers based on a multidentate N-donor ligand, Zn(II) ions, and two aromatic polycarboxylate anions have been synthesized and characterized. The optical band gaps and photoluminescent spectra of the compounds have been investigated.

Three coordination polymers constructed from a multidentate N-donor ligand, polycarboxylate anions and Zn(II)/Ag(I)/Mn(II) ions: synthesis, structures, characterization and pH-dependent photoluminescence

Three new coordination polymers, namely {[Zn(5-OH-bdc)(2,4′-tmbpt)]·5H2O}n (1), [Ag3(L)(2,4′-tmbpt)2]n (2), and [Mn3(L)2(2,4′-tmbpt)2]n (3), have been prepared under hydrothermal condition (2,4′-tmbpt = 1-((1H-1,2,4-triazol-1-yl)methyl)-3-(4-pyridyl)-5-(2-pyridyl)-1,2,4-triazole, 5-OH-H2bdc = 5-hydroxy-1,3-benzenedicarboxylic acid, and L = 5-(4-carboxybenzyloxy)isophthalic acid). The structures of compounds 1–3 have been determined by single-crystal X-ray diffraction analysis. The structures of 1 and 3 have been characterized by elemental analysis, infrared spectra, powder X-ray diffraction analysis and thermogravimetric analysis. Compound 1 displays a 2D 4-connected sql net with the Schlafli symbol of (44·62), which is further connected by the intermolecular hydrogen bonds to generate a 3D supramolecular architecture. Compound 2 is a 3D two fold interpenetrating framework with the Schlafli symbol of (3·6·7)(32·83·9)(3·64·72·8·9·10). Compound 3 is a 3D (3,6,6)-connected framework with the Schlafli symbol of (3·62)(34·66·85)(33·68·83·10). The pH-dependent photoluminescent spectra of compound 1 have been investigated, and the pH-dependent photoluminescent mechanism has been discussed and proved by UV–Vis absorption spectra. Three compounds based on a multidentate N-donor ligand, Zn(II)/Ag(I)/Mn(II) ions and polycarboxylic acids have been synthesized under the hydrothermal conditions. The structures of these compounds have been characterized comprehensively. The pH-dependent photoluminescent spectra of compound 1 have been investigated. Moreover, the pH-dependent photoluminescent mechanism has been discussed and proved by UV–Vis absorption spectra.

Four high-dimensional compounds constructed from V-shaped multidentate organic ligands and octamolybdates: Syntheses, crystal structures and properties

By using a V-shaped multidentate N-donor ligand, four new octamolybdate-based inorganic-organic hybrids, formulated as [Cu4(H3X)4(H2O)2(β-Mo8O26)2]·7H2O (1), [Cu2(H2X)(β-Mo8O26)0.5]·H2O (2), [Co(H3X)2(H4Mo8O28)] (3) and [Ni(H3X)2(H4Mo8O28)] (4) (H2X = 2,6-dimethyl-3,5-bis(pyrazol-3-yl)pyridine), have been synthesized successfully under hydrothermal conditions and characterized by single crystal X-ray diffraction analyses, elemental analyses and IR spectra. Compounds 1 and 2 with helical chains exhibit three-dimensional (3D) frameworks with (3,4)-connected {83}2{85;10} and (3,4,6)-connected {4;62}2{42;64}2{42;68;82;103} topologies, respectively. Compounds 3 and 4 are isostructural, in which [H4Mo8O28]4− clusters act as bidentate ligands to join 1D {[M(H3X)2]4+}n (M = Co or Ni) chains to generate a 2D layer. Moreover, the luminescent properties of compounds 1 and 2 have been investigated. The electrochemical study displays that compound 3 could be used as electrocatalysts in the electrical reduction of nitrite.

Correction: Isopolymolybdate-based inorganic-organic hybrid compounds constructed by multidentate N-donor ligands: syntheses, structures and properties.

Correction for 'Isopolymolybdate-based inorganic-organic hybrid compounds constructed by multidentate N-donor ligands: syntheses, structures and properties' by Haiyang Guo et al., Dalton Trans., 2019, DOI: 10.1039/c9dt00119k.

Isopolymolybdate-based inorganic-organic hybrid compounds constructed by multidentate N-donor ligands: syntheses, structures and properties.

Taking advantage of isopolymolybdate [(NH4)6Mo7O24·4H2O] as a POM building block with multidentate N-donor molecules (tris[(2-pyridyl)methyl]amine = TPMA, 1-(tetrazo-5-yl)-3-(triazo-1-yl)benzene = 1,3-ttb) as organic ligands, five different inorganic-organic hybrid compounds were synthesized and characterized by single-crystal X-ray diffraction, infrared spectroscopy (IR) and powder X-ray diffraction (PXRD). Compound 1 is a Mo(vi)-based structure in which the TPMA ligand shows a tridentate coordination mode, which bears an uncoordinated pyridyl arm, and can further react with transition metals. Compound 2 exhibits a Cu(ii)-based zero-dimensional (0D) structure consisting of the TPMA ligand and [β-Mo8O26] polyanion. Compounds 3 and 4 have the same molecular formula with slight structural differences; both have the Co(ii)-based one-dimensional (1D) chain structure. Compared to the β-Mo8O26 polyanion in compound 3, the [Mo8O28]8- units condense via sharing two common terminal O atoms to form infinite [Mo8O26]n4n- chains in compound 4. Compound 5 is a Cu(ii)-based two-dimensional (2D) layer structure consisting of TPMA and 1,3-ttb mixed ligands and [β-Mo8O26]. In addition, the electrochemical properties and photocatalytic activities for the degradation of two types of organic dyes were explored for several compounds.

A pH-controlled fluorescent sensor and logic gate based on a 1D → 2D → 3D Cd(II)-containing coordination polymer

Hydrothermal reaction of the multidentate N-donor ligand 1-((1H-1,2,4-triazol-1-yl)methyl)-3-(4-pyridyl)-5-(2-pyridyl)-1,2,4-triazole (2,4′-tmbpt), 5-hydroxy-1,3-benzenedicarboxylic acid (5-OH-H2bdc), and Cd(CH3COO)2·2H2O in the presence of NaOH afforded a coordination polymer [Cd(2,4′-tmbpt)2(5-OH-bdc)]·5H2O (1), which exhibits a 1D→2D→3D supramolecular architecture. The photoluminescent spectra of the compound in different aqueous solutions in the pH range of 1–14 have been investigated. The results indicate that compound 1 can be used as an efficient pH fluorescent sensor and molecular logic gate. The pH sensing mechanism of the compound has been discussed and proved by the UV–Vis spectra.

Metal ions directed assembly of two coordination polymers based on an organic phosphonate anion and a multidentate N-donor ligand

Two new coordination polymers [Cd(4,4′-tmbpt)(HL)(H2O)] (1) and [Cu(4,4′-tmbpt)(HL)]·H2O (2) (H3L = 2′-carboxybiphenyl-4-ylmethylphosphonic and 4,4′-tmbpt = 1-((1H-1,2,4-triazol-1-yl)methyl)-3,5-bis(4-pyridyl)-1,2,4-triazole) have been synthesized hydrothermally. The two compounds have the same metal to ligand ratio, but different metal ions. As a result, the two compounds display different 2D layer structures, which is mainly caused by the different coordination numbers of the different metal ions. The effects of the metal ions on the structures, the optical band gaps and photoluminescent and photocatalytic properties of the compounds have been studied.

Syntheses, structures, and properties of transition metal coordination polymers based on a long semirigid tetracarboxylic acid and multidentate N-donor ligands

Six transition metal coordination polymers based on a semirigid tetracarboxylic acid and the multidentate N-donor ligands have been synthesized by the hydrothermal method, namely, {[Co(H2obda) (μ2-H2O) (H2O)2]·2H2O}n (1), {[Co(obda)0.5(bpe) (H2O)2]·3H2O}n (2), {[Zn(H2obda) (H2O)4]·H4obda·6H2O}n (3), {[Zn(bpy) (H2O)4]·H2obda}n (4), {[Ni(bpy) (H2O)4]·H2obda}n (5) and {[Cu(H2obda) (bpy)2]}n (6) (H4obda = 1,4-bis(4-oxy-1,2-benzene dicarboxylic acid)benzene, bpe = 1,2-Bis(4-pyridyl)ethylene), bpy = 4,4′-bipyridine). Compounds 1–6 were structurally characterized by the elemental analyses, infrared spectra, and single crystal X-ray diffractions. Compounds 1–2 exhibit the 2D quadrilateral and polygonal layered grid structures, respectively; a 3D supramolecular structure of 2 has been build via π···π and hydrogen bonds interactions. Compounds 3–6 reveal the 1D zigzag and linear chains structures, respectively; furthermore, 3–5 display the diverse 3D supramolecular structures via hydrogen bonds, respectively. The 1-D infinite water chain in 3 has been found between the lattice water molecules. In addition, the thermogravimetric analyses of 1–6, magnetic property of 1, and photoluminescence of 3–4 have been investigated, respectively.

Synthesis, structure and properties of a novel 3D pentanuclear [Zn5(OH)2]8 + cluster-based (3,4,11)-connected coordination polymer

A novel coordination polymer based on the multidentate N-donor ligand 1-((1H-1,2,4-triazol-1-yl)methyl)-3,5-bis(3-pyridyl)-1,2,4-triazole (3,3′-tmbpt) and 1,2,4,5-benzenetetracarboxylate anion (btec), namely, [Zn5(3,3′-tmbpt)(btec)2(OH)2] (1), has been synthesized hydrothermally. Compound 1 displays a rare 3D (3,4,11)-connected framework based on a [Zn5(OH)2]8+ cluster. The optical band gap and photoluminescent property of compound 1 have been studied.

Two highly connected frameworks and one polythreading architecture based on multidentate N-donor ligands: Syntheses, structures, characterizations and photoluminescent properties

Three coordination polymers based on multidentate N-donor ligands and polycarboxylate anions, namely, [Co3(4,4′-tmbpt)4(btc)2]·9.5H2O (1), [Ag4(4,4′-tmbpt)(btec)(H2O)2]·H2O (2) and [Zn(4,4′-tmbpt)(btec)0.5(H2O)]·0.5H2O (3) (4,4′-tmbpt=1-((1H-1,2,4-triazol-1-yl)methyl)-3,5-bis(4-pyridyl)-1,2,4-triazole, H3btc=1,3,5-benzenetricarboxylic acid, and H4btec=1,2,4,5-benzenetetracarboxylic acid) have been prepared under hydrothermal condition. Compound 1 displays a 3D (3,6,8)-connected framework with (4·62)(44·610·8)(414·612·82) topology. Compound 2 is a 3D (4,5,8)-connected framework with (43·62·8)(43·65·82)(48·62)(410·610·88) topology. Compound 3 exhibits a 2D→3D polythreading architecture. The photoluminescent spectra indicate that at room temperature, compounds 2 and 3 emit green and blue luminescence, respectively.

Syntheses, structures, characterization and photoluminescent properties of six coordination polymers based on multidentate N-donor ligands and polycarboxylate anions

A series of coordination polymers constructed from tripodal N-donor ligands and polycarboxylate anions, namely, [Ag6(3,4′-tmbpt)(btc)2]·2H2O (1), [Ag2(3,4′-tmbpt)(H2btec)]·H2O (2), [Ag2(4,4′-tmbpt)(Hbtc)]·H2O (3), [Cd3(4,4′-tmbpt)(btc)2(H2O)6]·7H2O (4), [Co(4,4′-tmbpt)(btec)0.5(H2O)] (5) and [Ni(4,4′-tmbpt)(btec)0.5(H2O)] (6), where 3,4′-tmbpt=1-((1H-1,2,4-triazol-1-yl)methyl)-3-(4-pyridyl)-5-(3-pyridyl)-1,2,4-triazole, 4,4′-tmbpt=1-((1H-1,2,4-triazol-1-yl)methyl)-3,5-bis(4-pyridyl)-1,2,4-triazole, H3btc=1,3,5-benzenetricarboxylic acid, and H4btec=1,2,4,5-benzenetetracarboxylic acid, have been hydrothermally prepared. Single crystal X-ray diffraction analyses indicate that compound 1 exhibits a 3D (3,4,6)-connected framework with (4·62)2(6·85)2(4·62·83·12) topology. Compound 2 has a 3D (3,4)-connected framework with (63)2(42·64)(42·63·8) topology. Compound 3 exhibits a 2D layer structure. Compound 4 shows a 3D 2-fold interpenetrating framework with (6·102) topology. Compounds 5 and 6 exhibit similar 2D→3D polythreading architectures. These compounds have been characterized by infrared spectra (IR), elemental analyses and powder X-ray diffraction (PXRD) analyses. The effects of the organic anions on the structures of the compounds have been discussed. Moreover, the photoluminescent properties of the compounds have been investigated.

Syntheses, structures, and photocatalysis of five inorganic–organic hybrid compounds constructed from Keggin polyoxometalate clusters and multidentate N-donor ligands

Five inorganic–organic hybrid compounds have been prepared under hydrothermal conditions and characterized by single-crystal X-ray diffraction analyses, infrared spectra, elemental analyses, powder X-ray diffraction, and thermogravimetric analyses. In 1, each 2,2ʹ-tmbpt ligand links two Cu(II) ions to generate a highly undulated chain. The chains are further bridged by [SiW12O40]4‒ anions to form a layer. Compound 2 exhibits a 3-D (3,4,5)-connected framework with large channels, in which [SiW12O40]4‒ anions are tetradentate linkages. In 3, each 2,4ʹ-tmbpt links three Cu(II) ions to form 2-D layers, which are further linked by [SiW12O40]4‒ to yield a 3-D (3,4)-connected framework. In 4, each 4,4ʹ-tmbpt connects three Cu(II) ions to generate 1-D double chains. In 5, [PW12O40]3‒ link Cu(II) ions to generate 1-D chains. Compounds 1‒5 exhibit photocatalytic activities for degradation of methylene blue and rhodamine B.

Two Hybrid Compounds Based on Octamolybdate and an N‐Donor Multidentate Ligand: Syntheses, Structures, and Properties

Two polyoxometalate inorganic–organic hybrids based on octamolybdate and a multidentate N-donor ligand, [Ag4L4(γ-Mo8O26)]·2H2O (1), [Ni2L2(γ-Mo8O26)(H2O)8]·3H2O (2), in which L = 2,4,5-tri(4-pyridyl)imidazole, were synthesized under hydrothermal conditions. Compound 1 is constructed from octamolybdates (γ-Mo8O26)4–, 1D AgL chains, and 2D AgL layers, which are held together through N–H···O hydrogen bonds between the chain/layer and the octamolybdates, extending into a 3D supramolecular structure. Compound 2 displays a 1D infinite chain structure. The chains are formed by coordination of the nitrogen atoms of the ligand to the five-coordinate molybdenum atoms of (γ-Mo8O26)4– and the Ni ions through the Mo–N–Ni bond and are further linked by N–H···O hydrogen bonds to form a 3D supramolecular architecture. Compound 2, to the best of our knowledge, is the first example of an octamolybdate anion decorated by a big tridentate N-donor organic molecule. The compounds were further characterized by IR spectroscopy, UV/Vis diffuse reflectance spectroscopy, photoluminescent spectroscopy, magnetic measurements, thermogravimetric analysis, and powder X-ray diffraction. Moreover, their photocatalysis properties for degradation of methylene blue upon UV irradiation were examined.

Efficient Chemical and Visible‐Light‐Driven Water Oxidation using Nickel Complexes and Salts as Precatalysts

Chemical and visible-light-driven water oxidation catalyzed by a number of Ni complexes and salts have been investigated at pH 7-9 in borate buffer. For chemical oxidation, [Ru(bpy)3](3+) (bpy = 2,2'-bipyridine) was used as the oxidant, with turnover numbers (TONs) >65 and a maximum turnover frequency (TOFmax) >0.9 s(-1). Notably, simple Ni salts such as Ni(NO3 )2 are more active than Ni complexes that bear multidentate N-donor ligands. The Ni complexes and salts are also active catalysts for visible-light-driven water oxidation that uses [Ru(bpy)3](2+) as the photosensitizer and S2 O8 (2-) as the sacrificial oxidant; a TON>1200 was obtained at pH 8.5 by using Ni(NO3)2 as the catalyst. Dynamic light scattering measurements revealed the formation of nanoparticles in chemical and visible-light-driven water oxidation by the Ni catalysts. These nanoparticles aggregated during water oxidation to form submicron particles that were isolated and shown to be partially reduced β-NiOOH by various techniques, which include SEM, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, XRD, and IR spectroscopy. These results suggest that the Ni complexes and salts act as precatalysts that decompose under oxidative conditions to form an active nickel oxide catalyst. The nature of this active oxide catalyst is discussed.

Synthesis, structure and luminescence properties of cadmium(II) complexes with 2,4,6-tri(2-pyridyl)-1,3,5-triazine

The paper presents a combined experimental and computational study for two cadmium(II) complexes [Cd(dca)(NO3)(tptz)(H2O)]·2H2O (1) and [Cd(dca)(OAc) (tptz)(H2O)]·2H2O (2) (tptz=2,4,6-tri(2-pyridyl)-1,3,5-triazine and dca=dicyanamide anion). The compounds have been studied by IR, UV–vis spectroscopy and single crystal X-ray analysis. Due to the presence of multidentate N-donor ligand, coordinated water molecule and nitrate or acetate groups together with the lattice water molecules their crystal structures are dominated by the hydrogen-bonding interactions that give rise to the supramolecular architectures.The luminescent properties of compounds 1 and 2 have been studied in solution and solid state and compared with the free ligand. The studies revealed that the fluorescence of tptz ligand and complexes 1 and 2 was concentration and solvent dependent. To get detailed insight into the electronic structure and spectroscopic properties of [Cd(dca)(NO3)(tptz)(H2O)] and [Cd(dca)(OAc) (tptz)(H2O)], the density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were performed.

A Series of Coordination Polymers Constructed from a Multidentate N-Donor Ligand and Varied Carboxylate Anions: Syntheses, Structures, and Luminescent Properties

Ten new coordination polymers, [Zn2(Htrb)(L1)2]·8H2O (1), [Zn2(Htrb)(HL2)2(H2O)2]·4H2O (2), [Co2(Htrb)(HL2)2(H2O)2]·4H2O (3), [Cd2(Htrb)(HL2)2(H2O)2]·4H2O (4), [Cu3(Htrb)(L2)2(H2O)2]·8H2O (5), [Ag5(Htrb)(HL2)(L2)(H2O)2]·2H2O (6), [Ag6(Htrb)2(HL3)2(L4)]·2H3L3·6H2O (7), [Ag4(Htrb)2(H2L5)2] (8), [Ag6(Htrb)2(HL6)2(H2O)3]·2H2O (9), and [Ag2(Htrb)]·2NO3 (10), based on a hexadentate N-donor ligand hexakis(1,2,4-triazol-ylmethy1)benzene (Htrb) and different carboxylates, have been synthesized (H2L1 = 5-OH-1,3-benzenedicarboxylic acid, H3L2 = 1,3,5-benzenetricarboxylic acid, H3L3 = 1,2,4-benzenetricarboxylic acid, H2L4 = 2-CH2OH-1,4-benzenedicarboxylic acid, H4L5 = 3,3′,4,4′-benzophenone tetracarboxylate acid, and H4L6 = 4,4′-oxidiphthalic acid). Compounds 1–4 feature typical 2D binodal 4-connected networks with a (4·64·8)2(42·64) topology. Compound 5 exhibits a 3D (4,6)-connected (44·62)(44·610·8) framework. Compound 6 shows a 3D trinodal (6,8)-connected framework with a (34·44·52·65)2(34·412·54·68) topology. Compound 7 features an unusual 3D trinodal (4,6)-connected net with a (32·62·72)(3·4·5·62·8)2(32·42·52·64·72·83) topology. Compound 8 displays a 2D layer with a (3,4)-connected (4·62)2(42·62·82) topology. Compound 9 shows a uninodal 2D 4-connected network with a (44)(62) topology. Compound 10 reveals a 3D (4,8)-connected (46)2(412·612·84) net. The ligand effects on the complex structures were studied. Moreover, their luminescent emissions were studied at room temperature.

Anion-induced assembly of two distinct copper(II) coordination polymers with a versatile multidentate N-donor ligand

Reaction of a ligand N-(3,5-di-2-pyrazinyl-4H-1,2,4-triazol-4-yl)-2-pyrazinecarboxamide (Hpztp) with CuSO4 and Cu(acac)2 (acac = acetylacetonate), respectively, yields two distinct CuII coordination polymers {[Cu3(pztp)2(SO4)2(H2O)2]·3H2O}n and {[Cu(pztp)(acac)]·0.5H2O}n. Both complexes have been structurally determined and also characterized by physicochemical and spectroscopic methods. The results reveal that by using different anions (SO42− versus acac−), the dimensionality (from 2D to 1D) of the resulting coordination architectures as well as conformations and binding fashions of the pztp ligand are significantly changed. That is to say, the selection of anions will play a key role in inducing the formation of the crystalline materials. The thermal stabilities of both complexes have also been explored and discussed.

A series of coordination polymers assembled from d10 metals and a new multidentate N-donor ligand: syntheses, structures, and photoluminescent properties

Seven new coordination polymers based on d10 metals and multidentate N-donor ligands, namely [Na0.4Cd4(htpmb)(L1)3.2(Cl)2(H2O)2.4]·0.8H2L1·1.6H2O (1), [Cd4(htpmb)(L1)3(OH)2(H2O)2]·3H2O (2), [Zn2(htpmb)(L1)2]·H2L1·H2O (3), [Zn2(htpmb)(L1)2]·3H2O (4), [Zn2(htpmb)(HL2)4] (5), [Zn2(htpmb)(L3)4] (6), and [Cd4(htpmb)(L4)2(OH)2(H2O)3]·8H2O (7), where htpmb = hexakis(3-(1,3,4-triazol-1-yl)phenoxy-methyl)benzene, H2L1 = 1,4-benzenedicarboxylic acid, H2L2 = 2-hydroxy-benzoic acid, HL3 = benzoic acid and H3L4 = 5-hydroxy-1,3-benzenedicarboxylic acid, have been synthesized under hydrothermal conditions. Compounds 1 and 2 display the same 3D framework with new binodal 6-connected (45·55·65)(46·69) topology based on dinuclear Cd(II) units. Compounds 3 and 4 show identical 3D 2-fold interpenetrating frameworks with rare binodal 4-connected (4·64·8)(42·62·82) topology. Compounds 5 and 6 reveal a similar 1D chain structure. Compound 7 exhibits a 1D double chain structure. The complexes were structurally characterized by single-crystal X-ray diffraction analyses, elemental analyses, powder X-ray diffraction (PXRD), ultraviolet-visible absorption spectra (UV-vis), and infrared spectra (IR). The influences of coordination modes of the htpmb, and pH values on the structures of the coordination polymers have been discussed. The effects of central metals, carboxylate anions, and N-donor ligand on the final topologies have been discussed. The luminescent properties of the seven compounds have also been investigated in detail.