Synthesis, structures, luminescent and magnetic properties of four coordination polymers with the flexible 1,3-phenylenediacetate ligands

Four coordination polymers, [Zn(pda)(bpy)(H₂O)]_n·nH₂O (1), [Cd(pda)(prz)(H₂O)]_n (2), [Co₃(μ₃-OH)₂(pda)₂(pyz)]_n·2nH₂O (3) and [Pr₂(pda)₃(H₂O)₂]_n (4) (H₂pda=1,3-phenylendiacetic acid, bpy=4,4′-bipyridine, prz=piperazine and pyz=pyrazine) have been hydrothermally synthesized and characterized. Complex 1 is a 1D wheel-like chain structure, which is further extended into a 3D metal-organic supramolecular framework by H-bonds and π-π stacking interactions. Complex 2 is a 1D ladder-like chain structure, which is also further extended into a 3D metal-organic supramolecular framework by H-bonds. Complex 3 possess a 2D sheet structure with infrequent two pairs of double-helix chains. Complex 4 features a 3D structure. Both 1 and 2 display strong blue fluorescent emission at room temperature. Magnetic susceptibility measurements of complexes 3 and 4 exhibit antiferromagnetic interactions between the nearest metal ions, with C=9.99 and 3.43 cm³ mol⁻¹ K, and θ=−23.9 and −46.3 K, respectively.     

Synthesis,crystal structures and fluorescence properties of coordination polymers based on tetrahedral ligands and secondary bidentate linkers

Two coordination polymers, namely {[Co₂L(dpe)₂]·0.42H₂O} (1), and {[Zn₄L₂(dpe)₄]·4H₂O} (2), were solvothermally prepared from a flexible tetrapodal ligand tetrakis[(3-carboxyphenyl)oxamethyl]methane acid (H₄L) and a secondary bidentate linker (E)-1,2-di(pyridin-4-yl)ethane (dpe). Single-crystal X-ray diffraction analysis revealed that these compounds possess similar three-dimensional structures, in which the frameworks are constructed from dinuclear SBUs (secondary building units) [M₂(COOR)₄N₄] (M?=?Co or Zn) and tetrahedral L^4? linkers. The overall structures of both compounds can be described as (4, 6)-connected binodal networks, with a Schläfli symbol of {4²5³7}{4²5⁵6⁴7²8²} according to the topological analysis. Compound 2 exhibits strong photoluminescence at room temperature, with a peak at 422 nm (excitation at 370 nm), most probably from an intraligand and/or ligand-to-ligand charge transfer (LLCT). The emission of compound 2 was quenched efficiently by Fe³⁺ ion, suggesting that 2 could be used as a fluorescence sensor for Fe³⁺.     

Syntheses, crystal structures, and luminescent properties of three novel zinc coordination polymers with tetrazolyl ligands

The syntheses and luminescent properties of three novel zinc coordination polymers containing tetrazolyl ligands are described. In situ [2+3] cycloaddition reactions of acetonitrile or p-tolylnitrile with sodium azide in the presence of Zn(ClO(4))(2) as a Lewis acid (Demko-Sharpless tetrazole synthesis method) under hydrothermal (solvothermal) reaction conditions gave [Zn(CH(3)CN(4))(2)](3)(H(2)O) (1) and [Zn(4-MPTZ)(2)] (3) [4-MPTZ = 5-(4-methylphenyl)tetrazole], respectively. On the other hand, [Zn(HCN(4))(2)] (2) was obtained by directly reacting tetrazole with Zn(OAc)(2) under hydrothermal reaction conditions. The structure of 1 shows a super-diamond-like topological network with a diamond subunit as a connecting node. For 2, a diamond-like topological network is also found, but it is 2-fold interpenetrated. The structure of 3 reveals a 2D layered network with a hexagonal net, with the adjacent layers in the network stacked in an ABAB sequence. Photoluminescence studies revealed coordination polymers 1, 2, and 3 exhibit strong blue fluorescent emissions at lambda(max) = 396, 418, and 397 nm, respectively, in the solid state at room temperature.     

Syntheses,crystal structures and fluorescent properties of four one-dimensional lanthanide coordination polymers with 3-cyanobenzoato

The hydrothermal reactions of Nd(ClO₄)₃·6H₂O, Gd(ClO₄)₃·6H₂O, Dy(ClO₄)₃·6H₂O, Er(ClO₄)₃·6H₂O with 1,3-dicyanobenzene, give rise to four one-dimensional rare earth-based coordination polymers: [M(3-CNC₆H₄COO)₃(H₂O)₂] _n (where M?=?Nd (1), Gd (2), Dy (3), Er (4), 3-CNC₆H₄COO?=?3-cyanobenzoato), respectively. Their solid-state structures have been characterized by X-ray single-crystal diffraction studies. The results show that 1,3-dicyanobenzene hydrolyzed to give 3-cyanobenzoato under hydrothermal condition, and the four complexes are isomorphous. Crystal data for 1: triclinic, space group P-1, a?=?9.4063(19), b?=?11.485(2), c?=?12.616(3)?Å, α?=?66.38(3), β?=?74.01(3), γ?=?86.96(3)°, V?=?1197.9(4)?ų, Z?=?1, D _c?=?1.704?Mg?m^?3; for 2: triclinic, space group P-1, a?=?9.3712(19), b?=?11.446(2), c?=?12.627(3)?Å, α?=?65.86(3), β?=?73.89(3), γ?=?86.84(3)°, V?=?1184.8(4)?ų, Z?=?1, D _c?=?1.759?Mg?m^?3; for 3: triclinic, space group P-1, a?=?9.3425(19), b?=?11.432(2), c?=?12.703(3)?Å, α?=?65.28(3), β?=?73.80(3), γ?=?86.86(3)°, V?=?1180.6(4)?ų, Z?=?1, D _c?=?1.780?Mg?m^?3; for 4: triclinic, space group P-1, a?=?9.3425(19), b?=?11.432(2), c?=?12.703(3)?Å, α?=?65.28(3), β?=?73.80(3), γ?=?86.86(3)°, V?=?1180.6(4)?ų, Z?=?1, D _c?=?1.7794?Mg?m^?3. The fluorescence emission spectra of compounds 1 to 4 are also reported.     

Syntheses, crystal structures and properties of three novel coordination polymers with tripodal imidazole-containing ligands and benzenetetracarboxylate

Three novel coordination polymers, [Ni₂(tib)₂(btec)]·2H₂O (1), [Co₂(tib)₂(btec)]·2H₂O (2) and [Zn₄(tib)₂(btec)Cl₄]·2H₂O (3), have been synthesized by using mixed ligands of 1,3,5-tris(1-imidazolyl)benzene (tib) and 1,2,4,5-benzenetetracarboxylic acid (H4btec) under hydrothermal conditions. Complexes 1 and 2 have the same structure and are rare three-dimensional (3D) self-penetrating (3,4,5)-connected nets, while complex 3 is an unprecedented (3,4)-connected 3D net. The different structures of 1 (2) and 3 are ascribed to the distinct coordination geometry of the metal centers. The thermal stability and photoluminescence property of the complexes were investigated.     

Synthesis,crystal structures,and magnetic properties of three isomorphous helical coordination polymers

Three isomorphous coordination polymers of general formula {[M(H₂bna)·(DMF)₂·(H₂O)₂]·DMF}_n (M = Co for 1, Mn for 2, Ni for 3, respectively, where H₄bna = 2,2′-dihydroxy-[1,1′]-binaphthalene-3,3′-dicarboxylate) were synthesized under solvothermal conditions and characterized by FTIR, single crystal X-ray diffraction, thermogravimetric analysis, and X-ray power diffraction analysis. All three polymers crystallize in the same monoclinic space group P2₁/n. The complexes are assembled into 1D helical chains, and each adjacent helical chain of the same chirality is further connected to form a chiral layer by hydrogen bond interactions. The layers are packed in alternating left-(M) and right-handed (P) chirality arrays. Magnetic studies reveal the presence of antiferromagnetic coupling interactions in complexes 1 and 2.     

Synthesis, crystal structure and photoluminescent properties of four lanthanide 5-nitroisophthalate coordination polymers

Four new lanthanide coordination polymers, [Y(Hnip)(nip)(H₂O)]·H₂O (1), [Ln(Hnip)(nip)(H₂O)₂]·2H₂O [Ln=Eu(2), Tb(3)] and [Y(nip)₂]·(H₂4,4′-bpy)_0.5 (4) [5-nip=5-nitroisophthalate, 4,4′-bpy=4,4′-bipyridine], have been hydrothermally synthesized and structurally characterized. Compound 1 features novel lanthanide-carboxylate groups chains composed of three samehanded helical strands intersecting each other through hinged lanthanide atoms, and these chains are cross-linked by phenylene moieties of carboxylate ligands into a 2D layer structure. Compounds 2 and 3 are isomorphous, and contain 1D catenanelike Ln-O-C-O-Ln chains, which are interconnected by phenylene moieties into 2D layer structures. Compound 4, however, displays a 3D architecture sustained by strong hydrogen bonding interactions between the protonated 4,4′-bpy and the carboxyl oxygen atom from [Y₂(nip)₄]²⁻ with 2D layer structure, and 4,4′-bpy as the guest molecules exist in bilayer channel. The studies for the thermal stabilities of the four compounds show that compound 4 is more stable than other compounds. Compound 2 emits characteristic red luminescence of Eu³⁺ ions at room temperature, and its luminescent lifetime and quantum efficiency has been determined.     

Two manganese(II) coordination polymers containing semirigid bis(benzimidazole) ligands: synthesis,crystal structures,and catalytic properties

Two ternary mixed Mn(II) coordination polymers (CPs), namely [Mn(L1)(Hnip)₂] _n (1) and [Mn(H_0.5L2)₂(H_1.5btc)₂] _n (2) (H₂nip = 5-nitroisophthalic acid, L1 = 1, 4-bis(5,6-dimethylbenzimidazol-1-ylmethyl)benzene, H₃btc = 1,3,5-benzenetricarboxylic acid, L2 = 4,4′-bis(benzimidazol-1-ylmethyl)biphenyl), have been synthesized under hydrothermal conditions and structurally characterized. CP 1 exhibits a non-interpenetrated six-connected pcu framework with the point symbol {4¹²·6³}, while CP 2 features a metal-carboxylate loop-like chain, which is further assembled into a 3D supramolecular network via hydrogen bonds and π–π interactions. The thermal stabilities, luminescence, and catalytic properties of both CPs for the degradation of methyl orange in a Fenton-like reaction have also been investigated.     

Synthesis,structures, and magnetic properties of two closely-related manganese(II) coordination polymers

The reactions of Mn²⁺ ion with 4-nitrobenzene-1,2-bicarboxylic acid in the presence of bipyridyl-type coligands gave two new manganese(II) coordination polymers, [Mn₂(Nbdc)₂(Bipyp)(H₂O)₄] _n (I) and [Mn₂(Nbdc)₂(Bipye)(H₂O)₄] _n (II) (H₂Nbdc = 4-nitrobenzene-1,2-bicarboxylic acid, Bipyp = 1,3-bi(4-pyridyl)propane, and Bipye = 1,2-bi(4-pyridyl)ethane). Both two complexes contain uniform carboxyl-bridged manganese chains with the composition of [Mn₂(Nbdc)₂(H₂O)₄] _n , which are interlinked by interchain Bipyp/Bipye spacers to afford two closely-related layers (CIF files CCDC nos. 1008182 (I) and 1008183 (II)). Magnetic studies for two compounds show the presence of similar antiferromagnetic couplings between the adjacent Mn²⁺ ions through the carboxyl bridges, the best fittings to the experimental magnetic susceptibilities gave J =–0.20 cm^–1 and g = 1.96 for I, and J =–0.24 cm^–1 and g = 1.98 for II. Similar magnetic parameters and thermal behaviors further verify that two compounds possess closely-related structures.     

Synthesis,crystal structures and catalytic properties of three-dimensional nickel(II) and manganese(II) coordination polymers with dicarboxylate and semi-rigid bis(imidazole) ligands

Two coordination polymers (CPs), namely [Ni(L)(chdc)] _n (1) and [Mn(L)(ndc)(H₂O)] _n (2) (L = 4,4′-bis(imidazol-1-ylmethyl)biphenyl, H₂chdc = 1,2-cyclohexanedicarboxylic acid, H₂ndc = 2,6-naphthalenedicarboxylic acid), have been hydrothermally synthesized and characterized by physicochemical and spectroscopic methods and also by single-crystal diffraction. Both CPs feature 3D-diamond-like networks with point symbol of 6⁶; CP-1 displays a 2-fold interpenetrated net, while CP-2 presents a non-interpenetrated framework. The thermal stabilities, solid-state luminescence properties and catalytic activities of both CPs for degradation of methyl orange in a Fenton-like process were investigated.     

Synthesis,crystal structures and properties of three glutarato and adipato bridged manganese(II) coordination polymers under ambient conditions

Three Mn(II) polymers Mn(H₂O)₄(C₅H₆O₄) 1, [Mn(H₂O)₂(C₅H₆O₄)]·H₂O 2 and Mn(H₂O)(C₆H₈O₄) 3 were synthesized (H₂(C₅H₆O₄) = glutaric acid, H₂(C₆H₈O₄) = adipic acid) under mild ambient conditions. The [Mn(H₂O)₂]²⁺ units in 2 are interlinked by the glutarate anions with a η⁴μ₃ bridging mode to form 2D (4·8²) topological networks, which are stacked via interlayer hydrogen bonds into a 3D (4³·6⁵·8²)(4⁷·6³) topological net. Compound 3 crystallizes in the acentric space group P2₁ and exhibits significant ferroelectricity (remnant polarization Pr = 0.371 nC cm⁻², coercive field Ec = 0.028 kV cm⁻¹, saturation of the spontaneous polarization Ps = 0.972 nC cm⁻²). The adjacent MnO₆ octahedrons in 3 are one atom-shared to generate the Mn₂O₁₁ bi-octahedron, leading into 1D metal oxide chains. The resulting chains are interconnected by the η⁵μ₅ adipate anions to form new 2D (4⁸·6²) networks, which are held together via strong interlayer hydrogen bonds into 3D α-Po topological supra-molecular architecture. The temperature-dependent magnetic susceptibility data of 1–3 shows overall anti-ferromagnetic interactions between the metal ions bridged by the carboxylate groups.     

Syntheses, crystal structures, and characterization of four homochiral coordination polymers based on two chiral reduced Schiff base ligands

Four homochiral coordination polymers incorporating two chiral reduced Schiff base ligands, namely, [Cu(L¹)(H₂O)]·H₂O (1), [Zn₂(L²)₂] (2), [Co(L²)(H₂O)] (3), and [Ni(L²)(H₂O)] (4) (H₂L¹ = N-(4-carboxyl)benzyl-l-alanine, H₂L² = N-(4-carboxyl)benzyl-l-leucine) have been obtained by hydrothermal methods and characterized by physico-chemical and spectroscopic methods. X-ray crystallographic analysis reveals that complex 1 exhibits a chain structure with 1D channels. Complexes 2–4 all are 3D network structures with 1D channels in which the isobutyl group of the ligand points toward to the channel. Complex 2 displays strong photoluminescent emission in the purple region.     

Synthesis, crystal structures and characterization of four coordination polymers based on 5-amino-2,4,6-triiodoisophthalic acid

One homochiral 1D coordination polymer [Cu(ATIBDC)(2,2′-bipy)]·3H₂O·CH₃OH (1) and three achiral 1D coordination polymers: [Cd(ATIBDC)(2,2′-bipy)(H₂O)]·3H₂O (2), [Cd(ATIBDC)(phen)(H₂O)]·4H₂O (3), and [Mn(ATIBDC)(phen)₂]·5H₂O (4) have been synthesized and characterized (H₂ATIBDC=5-amino-2,4,6-triiodoisophthalic acid, 2,2′-bipy=2,2′-bipyridine, and phen=1,10-phenanthroline). Extended high dimensional network architectures are further constructed with the help of weak secondary interactions, such as hydrogen bonding, aromatic stacking, and halogen bonding (C-I…π and C-I…N/O). Complex 1 crystallizes in the monoclinic system with chiral space group P2(1) and exhibits a right-handed 2₁ helical chain structure. The homochirality of 1 was confirmed by CD spectrum. Interestingly, two new configurations of decameric water cluster are found in 3 and 4. The acyclic tetrameric cluster (H₂O)₃(CH₃OH) in 1 and (H₂O)₄ in 2 array into highly ordered helical infinite chains. Thermal stabilities of all the complexes have been studied. Solid state fluorescent properties of the Cd(II) complexes have been explored.     

Synthesis,structures, and properties of a series of similar structural coordination polymers with triphosphonate anions as ligands

The hydrothermal reactions of metal precursors with aminotri(methylenephosphonic acid) yielded a series of similar structural coordination polymers of general formula {M[HN(CH₂PO₃H)₃](H₂O)₃}_n [M = Mg(II) (1), Mn(II) (2), Co(II) (3), Zn(II) (4) and Cd(II) (5)]. Compounds 1–5 were characterized by X-ray single crystal diffraction, elemental analyses, and thermogravimetric analyses. Compounds 1–5 all reveal the wave-like 1D chain structures and the structures are constructed by two types of eight-membered, square-like rings linked alternatively via the phosphonate oxygen atoms, generating double-channel systems. The magnetic studies of 2 and 3 reveal that antiferromagnetic interactions are mediated between the metal ions.     

Synthesis,crystal structure,and properties of cobalt,zinc, and manganese coordination polymers based on fluconazole

Three complexes based on fluconazole, namely, {[Co₂(HFlu)(dpa)₂(H₂O)₂]·H₂O}_n (1), {[Zn(HFlu)(IPA)]·H₂O}_n (2), and {[Mn(HFlu)₂(IPA)(H₂O)]·H₂O}_n (3) (HFlu?=?fluconazole, 2-(2,4-difluoro-phenyl)-1,3-bis(1,2,4-triazol-1-yl)-propan-2-ol; H₂dpa?=?diphenic acid; H₂IPA?=?isophthalic acid) have been synthesized. Single-crystal X-ray analysis revealed that 1 is a 2-D-network framework containing a trinuclear Co(II) unit, 2 is a 3-D framework, and 3 is 1-D double chain structure with a Mn₂ metallocyclic core. The complexes have also been characterized by elemental analyses, IR, UV/vis and fluorescence spectroscopy, and thermal gravimetry. The phase purity of these polymers has been confirmed via powder X-ray diffraction.     

Synthesis and coordination properties of new macrocyclic ligands: equilibrium studies and crystal structures

The synthesis and characterization of two new macrocyclic ligands, the bis-macrocyclic compound 2,6-bis(1,4,13-triaza-7,10-dioxacyclopentadec-1-ylmethyl)phenol (L) and 38-methoxy-1,4,13,16,19,28-hexaaza-7,10,22,25-tetraoxatricyclo[14.14.7.1(32,36)]octatriconta-32,34,Delta(36,38)-triene (L1) are reported. Equilibrium studies of basicity and coordination properties toward metal ions such as Cu(II), Zn(II), Cd(II) and Pb(II) were performed for ligand by potentiometric measurements in aqueous solution (298.1 +/- 0.1 K, I= 0.15 mol dm(-3)). L behaves as a hexaprotic base (logK(1)= 10.93, logK(2)= 9.70, logK(3)= 8.79, logK(4)= 8.05, logK(5)= 6.83, logK(6)= 2.55). All metal ions form stable mono- and dinuclear complexes: logK(MLH(-1))= 25.61 for Cu(II), 15.37 for Zn(II), 12.58 for Cd(II) and 13.79 for Pb(II); logK(M(2)LH(-1))= 31.61 for Cu(II), 23.38 for Zn(II), 24.49 for Cd(II) and 23.68 for Pb(II). All these dinuclear species show a great tendency to add the OH(-) group: the equilibrium constant for the addition reaction was found to be logK(M(2)LH(-1)OH)= 4.77 for Cu(II), 5.66 for Zn(II), 2.8 for Cd(II) and 3.18 for Pb(II). In the case of Ni(II), kinetic inertness prevents the possibility of solution studies. The dinuclear solid adducts [Ni(2)H(-1)L(N(3))(3)].EtOH and [Cu(2)H(-1)L(N(3))](ClO(4))(2) were characterized by X-ray analysis.     

Synthesis and crystal structures of three novel coordination polymers generated from AgCN and AgSCN with flexible N-donor ligands

The solvothermal reactions of AgX (X = CN, SCN) with mbix [mbix = 1,3-bis(imidazole-l-yl-methyl)benzene] or bix [bix = 1,4-bis(imidazole-l-yl-methyl)benzene] afforded the polymers [AgCN(mbix)]_n (1), [(AgCN)₄(bix)₂]_n (2) and [(AgSCN)₂(mbix)]_n (3). They were all characterized by infrared spectroscopy, elemental analysis and X-ray single-crystal analysis. The structure of 1 contains a 3-fold-interpenetrated 2D network, while that of 2 exhibits 2-fold parallel interpenetration. There is no interpenetration observed in 3. Compounds 2 and 3 show 3D supramolecular structures built from 2D networks through weak π ? π interactions. The photoluminescent properties of the present compounds were also investigated.     

Syntheses,crystal structures and properties of four metal coordination complexes constructed from aromatic carboxylate and benzimidazole-based ligands

Transition Metal Chemistry - Four metal–organic coordination complexes, namely {[Zn(SIP)(mbi)2]·(Hmbi)·(H2O)2}n (1), {[Cd3(SIP)2(bbhb)3(H2O)4]·(H2O)2}n (2),...     

Syntheses,crystal structures,and magnetic properties of 1-D coordination polymers

Three coordination polymers of Robson-type macrocycles, {[Cu₄L¹(4,4′-bipy)₂]·4ClO₄·H₂O}_∞ (1), {[Cu₄L²(4,4′-bipy)₄]·2CH₃CN·4ClO₄·2H₂O}_∞ (2), and {[Zn₂L²(4,4′-bipy)₂]·(ClO₄)₂}_∞ (3) (where H₂L¹ and H₂L² are the [2?+?2] condensation products of 1,3-diaminopropane with 2,6-diformyl-4-methylphenol and 2,6-diformyl-4-fluorophenol, respectively), have been synthesized and characterized. Magnetic susceptibility was measured for 1 and 2 from 2 to 300?K. The optimized magnetic data were J?=?–368.5?cm^?1, J′?=?40.5?cm^?1 with R?=?1.69?×?10^?6 for 1 and J?=?–291.22?cm^?1, J′?=?83.74?cm^?1, ρ = 0.00168 with R?=?1.8?×?10^?11 for 2, respectively. The data reveal strong antiferromagnetic interactions between two Cu(II) ions in the macrocyclic unit and ferromagnetic interaction between the Cu(II) ions in two adjacent macrocyclic units for 1 and 2.