Heterometallic complexes of macrocyclic oxamide with polycarboxylates: Syntheses,crystal structures,and magnetic properties

Three complexes with the formula [Co(Ip)(CuL)(H₂O)₂] · H₂O (I), [Co(Ip)(NiL)(H₂O)₂] · H₂O (II), [Co(CuL)₂(Hbtc)(H₂O)] (III), (H₂Ip = m-isophthalic acid; H₂L = 2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-dien; H₃Btc = 1,3,5-benzenetricarboxylic acid) were synthesized and structurally characterized by elemental analysis, IR and UV spectroscopy. Single-crystal X-ray analyses reveal that the complexes I and II contain neutral heterometallic binuclear CoM (for I and II, M = Cu, Ni, respectively) moieties, and complex III contains discrete neutral trinuclear CoCu₂ moieties. The structures of I–III consist of two-dimensional supramolecular architecture formed by strong O-H…O intermolecular hydrogen bonds. Furthermore, the magnetic properties of complex I were investigated and discussed in detail.     

Synthesis,Crystal Structure,and Luminescent Properties of Two Zn<Superscript>II</Superscript>/Cd<Superscript>II</Superscript> Coordination Polymers Based on 1,4-Bis(pyridine-3-Ylmethoxy)benzene

Two polymeric frameworks, [Zn(Dpb)(Oba)] _n (Ι) and [Cd(Dpb)(2,6-Pda)H₂O] _n · nH₂O (II) (Dpb = 1,4-bis(pyridin-3-ylmethoxy)benzene, H₂Oba = 4,4'-oxybis(benzoic acid), 2,6-H₂Pda = 2,6-pyridyl-dicarboxylate), have been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction method (CIF files CCDC 1488269 (Ι), 1488270 (II)). Complex Ι is a 2D layer structure, which is constructed from 1D double chain. Complex II is a 1D chain. The luminescent properties of Ι, II have been investigated with fluorescent spectra in the solid state, I and II displayed a strong fluorescent emission at room temperature.     

Construction of 0D to 3D Copper(II) MOFs based on heterocyclic carboxylic acid: Synthesis,structures, cyclic voltammograms,and luminescent properties

The crystal structures of MOFs [Cu(PDA)(Phen)(H₂O)]₂ · 5H₂O (I) and [Cu(PZCA)₂(H₂O)₂] · 2H₂O (II) (H₂PDA = pyridine-2,6-dicarboxylic acid, Phen = 1,10-phenanthroline, HPZCA = pyrazine-2-carboxylic acid, H₂PZDA = pyrazine-2,3-carboxylic acid) have been prepared under hydrothermal conditions. These MOFs have been characterized by element analysis, single-crystal X-ray diffraction, thermogravimetric analyses and IR spectroscopy. 3D frameworks of MOFs I and II are fabricated from zero-dimensional (0D) motifs through hydrogen bonds and π-π interactions. In MOF II, the PZCA ligand comes from in situ decarboxylation of the part of pyrazine-2,3-dicarboxylic acid (H₂PZDA). Luminescent emissions bands of MOF I in methanol have been measured at room temperature and it displays selectivity to Zn²⁺, Cu²⁺, Pb²⁺, and Cd²⁺ ions. Cyclic voltammetry of MOFs I and II showed that the Cu(II/I) couple is irreversible.     

New photoluminescent coordination polymers constructed from dicarboxylate and 1,2-bis(imidazol-1-ylmethyl)benzene

Two new metal-organic frameworks, namely, Cd(Pda)(Bix)_0.5(H₂O) (I) and Cd₂(Glut)₂(Bix)(H₂O) (II) (H₂Pda is 1,3-phenylenediacetic acid, H₂Glut is glutaric acid, and Bix is 1,4-bis(imidazol-1-ylmethyl)benzene), have been synthesized under hydrothermal conditions by employing mixed ligands with Cd(II) nitrate. In complex I, the adjacent Cd(II) atoms are bridged by two Pda ligands to result in 1D Cd(II)-Pda double chains, which are further linked by Bix ligands to generate a SQL with the node defined by a Cd(II) dimer, whereas II represents a three-dimensional coordination polymer with an unprecedented (4².5)₂(4⁴.5⁹.6⁸.7⁵.8²) topology, in which infinite cadmium-carboxylate chains are linked by the ligands to form a metal-organic coordination network. Moreover, the luminescence properties of two complexes have also been investigated.     

Syntheses,crystal structures,and properties of three two-dimensional complexes constructed by flexible (2,3-pyridylmethyl)amine

Three two-dimensional coordination polymers [Cd(2,3-Pyma)Cl₂] _n (I), {[Cd(2,3-Pyma)(1,4-Chdc)] · 4H₂O}n (II) and {[Zn₂(2,3-Pyma)(1,2,4,5-Bttc)(H₂O)₄] · 6H₂O} _n (III) (2,3-Pyma = (2,3-pyridylmethyl) amine, H₂-1,4-Chdc = 1,4-cyclohexanedicarboxylic acid, and H₄-1,2,4,5-Bttc = 1,2,4,5-benzenetetracarboxylic acid) have been synthesized and structurally characterized by single crystal X-ray crystallography (CIF files CCDC nos. 989461 (I), 1055685 (II) and 1055686 (III)). Three complexes are all twodimensional layer networks bridged by the flexible 2,3-Pyma ligands or the carboxylate ligands. It is noted that the flexible 1,4-Chdc ligands bind the Cd²⁺ ions into a helical chain structure in complex II. The photoluminescence and thermal properties are investigated.     

Hydrothermal synthesis, crystal structures, and properties of two Co(II) complexes based on 4-bromoisophthalic acid and N-donor ligands

Two new Co(II) complexes, [Co₂(H₂O)(Bipy)₂(Bript)₂] _n (I) and [Co(H₂O)(Phen)(Bript)] · H₂O (II), where H₂Bript = 4-bromoisophthalic acid, Bipy = 2,2??-bipyridine, and Phen = 1,10-phenanthroline, have been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. Complex I has binuclear units in which two Co²⁺ ions are bridged by two carboxylate groups and a coordinaiod-water molecule, and the binuclear units are connected by Bript to generate a 1D helical chain. These 1D helical chains are further linked by ????? stacking interactions to form a 3D supramolecular network, while complex II has a 2D layer motif. In I and II, there exists extensive hydrogen bonding interactions. The thermal behavior of the two corresponding complexes have briefly been investigated.     

Two novel four-coordinated zinc(II) polymers: Synthesis,structures, and properties

The synthsis, crystal structure, thermal analysis and spectroscopic studies of two novel zinc(II) coordination polymers Zn₄(NA)₄Dpa₂ (I) and Zn(Inic)(Bpdc)_0.5 (II) (NA = niacin, Inic = isonictinic acid, Dpa = 2,2′-biphenyldicarboxlate, Bpdc = 4,4′-biphenyldicarboxylate) are presented here. The crystal structure of I is a two-dimensional network whose tetranuclear unit is a slightly distorted square. Two kinds of ligand connect adjacent zinc(II) ions, respectively, in a coordinate direction. The structure of II is a three-dimensional and it consist of corrugated square layers of isonictinic acid-bridged zinc(II) ions which are pillared by 4,4′-biphenyldicarboxylate. The rod-ligands in II appear as useful tools to control the interlayer metal-metal separation. Each zinc(II) ion in I and II is four-coordinated with three oxygen atoms and one nitrogen atom building distorted tetrahedron environments.     

Hydrothermal synthesis, crystal structure of three novel complexes based on thiabendazole and 1,4-benzenedicarboxylate ligands

Three novel metal-organic complexes [Co(BDC)(TBZ)₂] (I), [Cd₂(BDC)₂(TBZ)₂(H₂O)₂] · 2(H₂O) (II), [Mn₂(BDC)(TBZ)₄(SO4)] (III) (BDC = 1,4-benzenedicarboxylate, TBZ = thiabendazole) have been prepared and characterized by IR spectrum, elemental analysis, thermogravimetric analysis, and single-crystal X-ray diffraction. X-ray structure analysis reveals that both three complexes are one-dimensional chain polymers. The 1D chain architecture of I is constructed from terephthalic acid and cobalt atoms. A simultaneous presence of chelating and monodentate coordination modes of BDC ligands is observed in complex II. In complex III, the coordinated BDC ligands adopt monodentate mode and with SO ₄ ^2? anions alternately bridge the Mn²⁺ ions into 1D chains. The 3D structures of the three complexes are stabilized by π-π stacking interactions and hydrogen-bonds.     

Synthesis, characterization, and antimicrobial activity of a novel proton salt and its Cu(II) complex

A novel proton transfer compound (H₂Ppz)(HDipic)₂ (I) obtained from 2-(piperazin-1-yl)ethanol (Ppz) and pyridine-2,6-dicarboxylic acid (H₂Dipic) and its Cu(II) complex (H₂Ppz)[Cu(Dipic)₂] · 6H₂O (II) have been prepared and characterized by elemental, spectral (¹H and ¹³C NMR, IR and Uv-Vis) and thermal analyses. Magnetic measurement and single crystal X-ray diffraction methods have also been applied for compound II. The molecular structure of II consists of one 1-(2-hydroxyethyl)piperazine-1,4-diium cation, one bis(pyridinium-2,6-dicarboxylate)Cu(II) anion and six uncoordinated water molecules. In complex II, the copper ion coordinates to two oxygen and one nitrogen atoms of two pyridine-2,6-dicarboxylate molecules forming an octahedral conformation. Furthermore, the synthesised compounds (I and II) were screened for their antimicrobial activities against Gram (?) (Escherichia coli and Pseudomonas aeruginosa) and Gram (+) (Staphylococcusaureus and Bacillus cereus). The results were reported, discussed and compared with the corresponding starting materials (H₂Dipic and Ppz).     

Construction of two metal coordination polymers based on 1,4-terephthalate and 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene

Two new metal-organic frameworks, namely, Cd(BDC)(Btx) · 0.25(H₂O) (I) and Co₃(BDC)₃(Btx)₄(H₂O)₄ (II) (H₂BDC = 1,4-terephthalate acid and Btx = 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene), have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, TGA, and single crystal X-ray diffraction. Complex I exhibits a scarcely reported an eight-connected (4²⁴.6⁴) net with dinuclear cadmium clusters as secondary building units, whereas complex II displays a three-dimensional co-ordination polymer with a rare (4,6)-connected net described by the (4⁴.6²)₂(4⁸.6⁷) Schläfli symbol. In addition, the luminescence measurements reveal that complex I exhibits strong fluorescent emissions in the solid state at room temperature.     

Two novel coordination polymers: Synthesis,structure, luminescent properties,and selective sensing of Cu<Superscript>2+</Superscript> and Mn<Superscript>2+</Superscript> ions

Two novel coordination polymers, namely {[Co(Ttac)_0.5(1,4-Bib)(H₂O)] · H₂O}_n (I) and {[La(HTtac)₂(2H₂O)] · H₂O}n (II) (H4Ttac = 4,5-di(3'-carboxylphenyl)-phthalic acid, 1,4-Bib = 1,4-bis(1-imidazoly) benzene), have been designed and successfully prepared via hydrothermal process, and characterized by elemental analyses, IR spectroscopy, and single crystal X-ray diffraction (CIF files CCDC nos. 1039298 (I), 1039300 (II)). Structural analysis reveals that the H₄Ttac ligands adopt different coordination modes in the as-synthesized I and II, and thus give rise to the targeted coordination polymers with different configurations. It is worth mentioning that, coordination polymer I is assembled from low-dimensional structures into three-dimensional (3D) via π···π stacking interactions, while three-dimensional coordination polymer II is formed by covalent bonds. Luminescent properties of coordination polymer II have been studied at ambient temperature. Significantly, luminescent measurement indicates that coordination polymer II may be acted as potential luminescent recognition sensors towards Cu²⁺ and Mn²⁺ ions.     

Diaquabromo(18-crown-6)rubidium and triaqua(18-crown-6)barium dibromide monohydrate: Synthesis and crystal structures

Two complexes are synthesized: diaquabromo(18-crown-6)rubidium [RbBr(18-crown-6)(H₂O)₂] (I) and triaqua(18-crown-6)barium dibromide monohydrate [Ba(18-crown-6)(H₂O)₃]²⁺ 2Br^? · H₂O (II). The orthorhombic structure of compound I (space group Pnma, a = 10.124 Å, b = 15.205 Å, c = 12.544 Å, Z = 4) and the monoclinic structure of compound II (space group C 2/c, a = 17.910 Å, b = 10.315 Å, c = 14.879 Å, β = 123.23°, Z = 4) are determined by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.063 (I) and 0.042 (II) for all 2293 (I) and 3363 (II) independent measured reflections (CAD-4 automated diffractometer, λMoK _α). The complex molecule [RbBr(18-crown-6)(H₂O)₂] in compound I and the randomly disordered cation [Ba(18-crown-6)(H₂O)₃]²⁺ in compound II are of the host-guest type: their Rb⁺ or Ba²⁺ cation (its coordination number is nine) is located in the cavity of the 18-crown-6 ligand and coordinated by all six O atoms. In structure I, the coordination polyhedron of Rb⁺ is a distorted hexagonal pyramid with a triple apex at the Br^? ligand and two O atoms of the water molecules. In structure II, the Ba²⁺ polyhedron is a distorted hexagonal bipyramid with one apex at the O atom of the water molecule and the other split apex at two O atoms of water molecules.     

Two new oxamidato-bridged CuII-CuII complexes: Synthesis, structure, spectra, and cyclic voltammetry studies

New oxamido-bridged binuclear Cu^II-Cu^II complexes, [Cu(Oxen)Cu(Bipy)₂](ClO₄)₂ (I) and [Cu(Oxen)Cu(4,4??-Bipy)₂(H₂O)₂](ClO₄)₂ (II) (Oxen is N,N??-bis(2-aminoethyl)oxamide dianion, Bipy = 2,2??-bipyridine, 4,4??-Bipy = 4,4??-bipyridine), have been constructed and structurally characterized by X-ray crystallography. In these two complexes, each Cu²⁺ ion is located in a slightly distorted square-pyramidal environment. Complex I is extended to two-dimensional by face-to-face ??-??-stacking with a distance of 3.648 II is raised to one-dimensional by face-to-face ??-??-stacking and intermolecular H-bonding interaction with distances of 3.651 and 2.767 I is also investigated.     

Solvothermal synthesis,crystal structure,and characterization of two new 2D Co(II)/Ni(II) coordination polymers with mixed-organic tectonics

Two new isomorphous coordination polymers [Co(4,4′-Bpda)(Dpa)] _n (I) and [Ni(4,4′-Bpda)(Dpa)] _n · H₂O (II) (4,4′-H₂Bpda = benzophenone-4,4′-dicarboxylic acid, Dpa = dipyridin-4-ylamine) were synthesized under solvothermal condition and characterized by elemental analysis, FT-IR and single-crystal X-ray diffraction technique. Compounds I and II exhibit 2D helical layers resulting from alternating single helical chains and double helical chains, which feature uninodal 4-connected topology with a point symbol of 6⁶.     

Crystal structures and electrochemical properties of two Mn(II) 2-sulfoterephthalate complexes with N-donor ligands

Two Mn(II) sulfoterephthalate complexes, [Mn(HStp)(o-Phen)₂] (I) and [Mn(HStp)(2,2′-Bipy)₂] (II) (H₃Stp = 2-sulfoterephthalic acid, o-Phen = 1,10-phenanthroline, 2,2′-Bipy = 2,2′-bipyridine), were synthesized under hydrothermal condition. Single crystal X-ray diffraction analyses reveal that complexes I and II possess similar structure, in which the center Mn²⁺ ions are hexa-coordinated with one Hstpanion and two N-donor ligands. For both of them, the formation of 3D supramolecular structures are based on both H-bonds and π...π/C-H...π stacking interactions. Electrochemical properties of complexes I and II have been investigated by means of cyclic voltmetry, which shows that electron transfer between Mn(III) and Mn(II) in electrolysis is quasi-reversible process.     

Novel 1D Mn(II) complexes containing aromatic dicarboxylic acids

Three Mn(II) complexes of [MnL(Bipy)(H₂O)] _n (I), [Mn₃(Phen)₂(HL)₂(L)₂]n (II), and [Mn(Phen)₂(HL)(OH)] (III), where L = 4,4′-(2-acetylpropane-1,3-diyl)dibenzoic acid, Bipy = 2,2′-bipyridine, and Phen = 1,10-phenanthroline, were hydrothermally synthesized and characterized by single crystal X-ray diffractions, infrared spectroscopy, thermogravimetric analyses, and magnetic analyses. Complexes I and II are one dimensional (1D) coordination polymers which can form the supramolecules with the help of the intermolecular hydrogen bond interactions. Finally, the landé factors are simulated by magentochemical analysis to be 2.15 and 1.80 for I and II with S = 5/2, respectively.     

Syntheses,Structures, and Properties of Two Zn(II)/Ag(I) Complexes Assembled from Tetracarboxylic Acids and N-Donor Ligands

Two new complexes {[Zn(H₂L)(Bpp)] · H₂O} _n (I) and {[Ag(H₃L)(Bpp)] · 0.25H₂O} _n (II) (H₄L = 5-(2,3-dicarboxy phenoxy) isophthalic acid, Bpp = 1,3-bis(4-pyridyl)propane) were prepared and characterized by single crystal X-ray diffraction (XRD) (CCDC nos. 1578523 (I), 1578529 (II)), element analysis and powder XRD. Compound I showed a one-dimensional chain structure, in which the zinc(II) ion is fourcoordinated with a tetrahedral geometry. Compound II is a 1D chain structure with the H₃L– suspension arms. Complexes I and II are further extended into three-dimensional supramolecular framework via hydrogen bonds and π–π interactions. The solid state luminescent properties of compounds I and II have been investigated.     

Hydrothermal synthesis, crystal structure, and photoluminescence of Pb(II) and Mn(II) coordination polymers based on imidazo[4,5-f][1,10]phenanthroline

Two new coordination polymers, [Pb(IDPT)₂(NO₃)₂] (I) and [Mn(IDPT)(SO₄)(H₂O)₂] (II) (IDPT = imidazo[4,5-f][1,10]phenanthroline), were synthesized by hydrothermal method and characterized by elemental analysis and single-crystal X-ray diffraction technique. The results reveal that the complex I belongs to monoclinic crystal system, space group C2/c and complex II belongs to monoclinic crystal system, P2₁/c space group. The cell parameters are: a = 19.1970(13), b = 7.3875(5), c = 17.3825(12) Å, β = 100.47(10)°, V = 2424.0(3) ų, Z = 4, F(000) = 1488 for I; a = 10.9135(6), b = 7.0230(4), c = 19.7034(10) Å, β = 99.32(10)°, V = 1490.25(14) ų, Z = 4, F(000) = 828 for II. In the structure of complex I, the metal center Pb(II) is six-coordinated, displays an octahedral geometry. Each molecule is further connected with neighboring one via π-π interactions into 1D chain. In complex II, Mn(II) is six-coordinated to form a distorted octahedral geometry. Compound II displays 1D supramolecular chain formed through hydrogen bonds. Additionally, the fluorescent properties for the complexes were investigated. Complexes I and II exhibit strong photoluminescence with emission maximum at 583 and 529 nm at room temperature.     

Syntheses and crystal structures of oxovanadium(V) complexes derived from N′-[1-(2-hydroxynaphthyl)ethylidene]-4-nitrobenzohydrazide and 2-hydroxy-N′-[1-(2-hydroxynaphthyl)ethylidene]benzohydrazide

Reactions of bis(acetylacetonato)oxovanadium(IV) with N??-[1-(2-hydroxynaphthyl)ethylidene]-4-nitrobenzohydrazide (H₂HNB) and 2-hydroxy-N??-[1-(2-hydroxynaphthyl)ethylidene]benzohydrazide (H₂HHB), respectively, product two oxovanadium(V) species with the formulas [VO(OMe)(HNB)]₂ (I) and [VO(OMe)(HHB)] (II). The complexes I and II have been characterized by elemental analysis, IR spectra, and single crystal X-ray diffraction. The crystal of I is monoclinic: space group P2₁/n, a = 8.208(2), b = 14.528(3), c = 16.418(3) ?, ?? = 97.887(3)°, V = 1939.3(7) ?³, Z = 2. The crystal of II is triclinic: space group P $P\bar 1$ a = 8.334(2), b = 10.236(2), c = 11.337(2) ?, ?? = 80.91(3)°, ?? = 75.41(3)°, ?? = 75.63(3)°, V = 902.0(3) ?³, Z = 2. Complex I is a methoxide-bridged dimeric oxovanadium(V) complex, and complex II is a mononuclear oxovanadium(V) complex. The V atom in I is in an octahedral coordination, and that in II is in a square pyramidal coordination.     

Synthesis and crystal and molecular structures of new copper and zinc complexes with aza-14-crown-4 ether having di(α-pyridyl)-substituted bispidine subunit

The complexes [Cu(L)(H₂O)](ClO₄)₂ · 2H₂O (I) and [Zn(L)Cl₂] · C₂H₅OH (II), where L is the macrocyclic substituted aza-14-crown-4 ether molecule containing di(α-pyridyl)bispidine insert, were synthesized and studied by X-ray diffraction. The Cu atoms in complex I and the Zn atoms in complex II have equal coordination numbers of 5 and different highly distorted polyhedra (the CuN₄O tetragonal pyramid and ZnN₃Cl₂ trigonal bipyramid). Ligand L in structure I performs the tetradentate tetrachelate (4N) structural function and in II, it performs the tridentate bis-chelate (3N) function. The key difference between the structures of complexes I and II is determined by different conformations of both the aza-macrocycles and bispidine substituents of ligand L.