Synthesis,crystal structure and photoluminescence of a new Cd(II) coordination polymer with unusual geometry

A new coordination polymer 1 [CdL₂(NO₃)₂]_n (L: 3, 6-di-(1, 2, 4-triazole-1-yl)-N-ethylcarbazole) has been synthesized by self-assembly reaction and characterized by elemental analysis and IR spectroscopy. The single-crystal X-ray diffraction shows that the [CdL₂(NO₃)₂]_n crystallizes in the monoclinic system and C2/m space group and the Cd(II) atom is four-coordinated. The coordination polyhedron can be described as a rectangle which is rather infrequent. The coordination bonds, hydrogen bonds and π–π interactions shaped the 3D network structure. A possible formation mechanism was discussed. The optical property was also studied.     

Solvent Control Over Structural Diversity of Two Copper (II) Complexes Based on Polyaromatic Acid Ligand

Abstract  

A new bipod polyaromatic acid ligand H₂bcm (H₂bcm = {2, 4-bis [(2′-carboxyphenoxy) methyl]-1,3,5-trimethylbenzene}) is prepared and its two novel binuclear coordination compounds, [Cu₂(bcm)₂(CH₃OH)₂]·2CH₃OH (1) and [Cu₂(bcm)₂(CH₃CH₂OH)₂]·2CH₃CH₂OH (2), have been synthesized with copper acetate and H₂bcm ligand in methanol solvent and ethanol solvent respectively, and characterized by the element analysis, IR, TGA and single crystal X-ray diffraction. The results of structural analysis indicate that 1 crystallizes in the triclinic system with space group P1, while 2 crystallizes in the monoclinic system with space group P2₁ /c. Furthermore, 1 adopts μ ₂ -COO⁻ and syn–syn coordination mode with Cu (II)···Cu (II) separation of 2.5868(11) ? and forms 1D zigzag chain structure by O···O interactions. The coordination of 2 is similar to that of 1 except that ethanol molecules are coordinated instead of methanol molecules with Cu (II)···Cu (II) separation of 2.5973(13) ?. Two-dimensional network structures of 1 and 2 are formed through π–π interactions.     

Preparation and structural characterisation of a Cd(II) complex with unusual geometry

Reaction of Cd(NO₃)₂ · 4H₂O with ethyl-2-pyridinecarboxylate yields [Cd(NO₃)₂(C₅H₄NCOOEt)₂]. Elemental analyses, conductivity measurements, infrared, ¹H and ¹³C{¹H} NMR spectroscopies and single-crystal X-ray diffraction enabled us to characterise this complex. The crystal structure consists of monomeric units in which the cadmium atom is eight-coordinated.     

Solvothermal synthesis,structure and photoluminescent properties of europium complex based on fluorene derivatives

A novel coordination polymer, {[Eu₂(L)₃(CH₃OH)(H₂O)]·(CH₃OH)(H₂O)}_n (1), has been synthesized by solvothermal reaction of Eu(NO₃)₃·6H₂O and 9,9-diethylfluorene-2,7-dicarboxylic acid in a mixture solution of CH₃OH and H₂O. Single crystal X-ray structural analysis reveals that complex 1 crystallizes in an orthorhombic, space group P2(1)2(1)2(1), holding the unusual (2,3,8)-connected 3D topological network. Thermogravimetric analysis shows remarkable thermal stability of the structural framework of compound 1, the photoluminescence properties are also discussed.     

Hydrothermal Crystal Growth,Structures and Thermal Properties of Co(II)-4,4′-bipyridine-Based Coordination Polymeric Materials

Hydrothermal synthetic parameters were studied and optimized for the preparation of new coordination polymeric materials based on Co(II) and 4,4′-bipy. A new polymeric compound, [Co₂(H₂O)₂(OH)₂(4,4′-bipy)₈](NO₃)₂·2(4,4′-bipy) 10(H₂O) (1), was prepared and structurally characterized by single crystal experiment. The framework of (1) is made up of two different one-dimensional substructures, i.e., the neutral chain A and positively charged chain B, both of which share the same nodes and node linkers. This is rarely found, especially from a one-pot crystal growth technique. Two other crystals were also identified, i.e., [Co(SO₄)(H₂O)₃(4,4′-bipy)]·2(H₂O), and K₂Co(H₂O)₆(SO₄)₂. The optimization of synthetic parameters apparently favors the formation of different polymeric structures, and this can be experimentally fine tuned. The influences of these parameters on phase formation, purity and crystal growth are discussed. The complicated thermogravimetric property of the new compound is also reported.     

Synthesis and crystal structure of mer-nitroaquatriamminenitrosylruthenium(II) nitrate [RuNO(NH3)3(NO2)(H2O)](NO3)2

The reaction between mer-[RuNO(NH₃)₃(NO₂)(OH)]Cl·0.5H₂O and an excess of 16 M HNO₃ leads to the protonation of the starting complex and crystallization of the complex with a coordinated water molecule and nitrite anion. The crystal structure of the product has been determined. The coordinated water molecule tends to be a weak acid with a measured pK_a of 2.4.     

Synthesis and characterization of the zinc(II) complex of a bleomycin analogue: a unique polymeric 2-[((2-(4-imidazoyl)ethyl)amino)carbony]-6-[((2-amino-2-methylpropyl)amino)methyl]pyridine zinc(II) nitrate complex

The reaction of 2-[((2-(4-imidazoyl)ethyl)amino)carbonyl]-6-[((2-amino-2-methylpropyl)amino)methyl]pyridine (L) with Zn^II(NO₃)₂·6H₂O has afforded a novel one-dimensional polymeric Zn^II complex, (Zn^II(L)(NO₃)₂)_n (2). Complex 2 crystallizes in the space group P2₁/n with a=8.955(3), b=13.216(3), c=18.941(3) Å, β=103.39(2)°, V=2180.6(10) ų, and Z=4. The geometry of each Zn^II is approximately a trigonal bipyramid: three nitrogens and one oxygen of the amide group are coordinated to the zinc while the fifth site is occupied by the imidazole nitrogen of a neighboring unit.     

Ferromagnetic dinuclear nickel(II) complexes bridged by azide ions

Dinuclear nickel(II) complexes, [Ni₂(mpapOH)₂(CH₃CO₂)(N₃)₃] (1) and [Ni₂(mpapOH)₂(N₃)₄]·CH₃OH (2) were synthesized by treating Ni(CH₃CO₂)₂·4H₂O and Ni(NO₃)₂·6H₂O in methanol, respectively, with mpapOH (= 2-methyl-2-[(2-pyridinylmethyl)amino]-1-propanol) and sodium azide; both 1 and 2 were characterized by elemental analysis, IR spectroscopy, X-ray diffraction, and magnetic susceptibility measurement. 1 was shown an asymmetric dinuclear structure, whereas 2 was displayed a symmetric dimeric one. 1 and 2 were exhibited end-on azido-bridged nickel(II) dinuclear units; corresponding ferromagnetic interactions through the bridged end-on azido ligands within the dimeric units were observed.     

Synthesis,structure and magnetic properties of a tetranuclear Mn(II) complex with carbohydrazone based ligand

A new tetranuclear complex of Mn(II), [Mn₄(L)₂(CH₃OH)₂(μ-N₃)₄(N₃)₂] ∙ 2(CH₃OH) (1), was synthesized and characterized by spectroscopic methods, single-crystal X-ray diffraction analysis and TGA analysis where HL is bis-[(E)-N′-(phenyl(pyridin-2-yl)methylene)]carbohydrazide. Single crystal X-ray analysis reveals that 1 has a Mn₄ core in which Mn(II) ions are connected by azide and enolate oxygen atoms. IR spectroscopy and X-ray analysis indicate that the carbohydrazone is coordinated to the metal cores as a mononegative ligand in the enol form. The magnetic behavior of 1 was investigated between 2 and 295 K and indicated that the magnetic coupling mediated via azide bridge is ferromagnetic whereas the enolate oxygen mediates antiferromagnetic coupling that leads to overall antiferromagnetic behavior.     

THE EXTRACTION BY N.N'TETRABUTYLGLUTARAMIDES II. EXTRACTION OF U(VI), Pu(IV) AND SOME FISSION PRODUCTS

The extraction of U(VI) and Pu(IV) from aqueous nitrate solutions by N,N'-tetrabutylglutaramide (TBGA) has been investigated. At low acidities, the extraction takes place via the formation of respectively UO₂(NO₃)₂. TBGA and Pu(NO₃)₄. TBGA which seem to be linked with additionnal molecules of TBGA in the second coordination sphere of the metal. When the saturation of TBGA by UO₂ ²⁺solutions is reached, the uranyl complex reorganizes to give a polymer (UO₂(NO₃)₂ TBGA)_x.

At high acidities, the anionic complexes : [UO₂(NO₃)₃, ^?] [HTBGA⁺] and probably [HPu(NO₃)₆?] [HTBGA+] are observed.     

Two uranyl–organic frameworks with pyridinecarboxylate ligands. A novel heterometallic uranyl–copper(II) complex with a cation–cation interaction

Reaction of uranyl nitrate with pyridine-2-carboxylic acid (HL¹) under hydrothermal conditions gives the complex [(UO₂)₃(L¹)₄(NO₃)₂], 1, which differs from the previously reported molecular complex, obtained at room temperature, by the absence of water, coordinated and free, and the extended carboxylate bridging. Although the trimetallic basic unit is similar in both cases, 1 crystallizes as a two-dimensional assembly. A heterometallic complex results from the reaction of uranyl nitrate and copper(II) trifluoromethanesulfonate with nicotinic acid (pyridine-3-carboxylic acid, HL²), [UO₂Cu(L²)₂(NO₃)₂], 2, in which copper nicotinate two-dimensional subunits are bridged by uranyl nitrate groups to give a three-dimensional framework. The copper atom environment geometry is elongated octahedral, with one of the axial donors being a uranyl oxo group (cation–cation interaction).     

Trinuclear and mononuclear nickel(II) complexes incorporating tridentate 2-[(pyridine-2-ylimine)methyl]phenol ligand: Syntheses, crystal structures and magnetic properties

[Ni₃(pymp)₄(pya)₂](NO₃)₂(CH₃OH)₂ (1), [Ni₃(pymp)₄(pya)₂]Cl₂(CH₃OH)₂ (2) and [Ni(pymp)₂(py)₂] (3) (Hpymp = 2-[(pyridine-2-ylimine)methyl]phenol, pya = pyridin-2-amine and py = pyridine) were synthesized and characterized. Crystal structures reveal that 1 and 2 contain phenoxo-bridged and N–C–N bridged linear trinuclear cores (uncommon for trinuclear nickel complexes), with the central Ni(II) being coordinated in a NiO₄N₂ fashion while the two terminal Ni(II) atoms adopt a NiO₂N₄ coordination mode. Two novel coordination modes of Hpymp ligand are presented in 1 and 2. Complex 3 displays a NiO₂N₄ coordination mode with the Ni(II) in a slightly distorted octahedral environment. Magnetic measurements of 1 indicated that the Ni centers are ferromagnetically coupled.     

Hydrothermal synthesis and crystal structure of a neutral cyclic tetranuclear cobalt(II) complex with 5-nitrosalicylate and 1,10-phenanthroline ligands

A novel complex, Co₄(phen)₄{5-(NO₂)sal}₄ (1) (5-(NO₂)sal = 5-nitrosalicylate anion, phen = 1,10-phenanthroline), have been prepared by hydrothermal synthesis and characterized by single crystal X-ray analysis, IR, TG, cyclic voltammogram and elemental analyses. This complex displays a neutral metallamacrocyclic structure containing [Co(phen)]²⁺ corner units and 5-(NO₂)sal bridging ligands.     

Copper(II) and cadmium(II) complexes with an imide tethered imidazole and a copper(II) coordination polymer through ring opening reaction

The reactions of 2-(3-(1H-imidazol-1-yl)propyl)isoindoline-1,3-dione (L) with copper (II) chloride or copper(II) nitrate resulted in mononuclear complexes [CuL₄Cl₂]·12H₂O (1) or [CuL₄(H₂O)NO₃]NO₃·2H₂O (2) respectively; whereas the copper(II) acetate reacted with L to give a three dimensional coordination polymer {[Cu(L′)₂]·4H₂O}n (3), (where L′ = 2-(3-(1H-imidazol-1-yl)propylcarbamoyl)benzoate). The reaction of cadmium(II) acetate with L led to the formation of a seven-coordinated complex [CdL₃(O₂CCH₃)₂]·2H₂O (4).     

Two rod-based 3-D lead(II) tetrafluoroterephthalate coordination frameworks with sra topology: Syntheses, structures, and properties

Two three-dimensional (3-D) Pb^II coordination frameworks [Pb(BDC-F₄)(CH₃OH)]_n (1) and [Pb(BDC-F₄)(DMF)(CH₃OH)]_n (2) have been prepared by the reactions of Pb(NO₃)₂ with a rigid dicarboxyl compound tetrafluoroterephthalic acid (H₂BDC-F₄) in different solvents. Single crystal X-ray diffraction reveals that both complexes show the unusual rod-based coordination networks with sra topology, although they crystallize in different space groups (C2/c and ). Their spectroscopic, thermal, and fluorescence properties have also been studied.     

Synthesis and characterization of [NBu4][La(CH3OH)2(DCU)NO3{Mo5O13(OMe)4(NO)}]·CH3OH: A novel Lanthanide-substituted Lindqvist-type oxo-nitrosyl polymolybdate

A 1:1 complex of Lanthanide-substituted Lindqvist-type oxo-nitrosyl polymolybdate [NBu₄][La(CH₃OH)₂(DCU)NO₃{Mo₅O₁₃(OMe)₄(NO)}]·CH₃OH (1) has been successfully synthesized by a one-pot self-assembly process of hydroxylamine hydrochloride with octamolybdate, DCC and La(NO₃)₃ in methanol under mild reaction conditions. The structure is determined by X-ray crystallography. It is notable that the compound is a Lindqvist-type POM with a capped lanthanum ion which is nine coordinated in a distorted square antiprism geometry. Interestingly, NO₃⁻ as the precursor, as well as the hydrated product DCU of DCC, are both coordinated with Lanthanum ion. The structure has also been characterized by IR, UV–vis and photoluminescence analysis. Photoluminescence analysis reveals that compound 1 emits weak green light in CH₃CN, with the maximum emission at 530 nm.     

One-Dimensional Cd(II) and Co(II) Coordination Polymers with Dinuclear Secondary Building Units Constructed by 1,1′-Biphenyl-3,3′-Dicarboxylic Acid: Synthesis, Structures, Luminescent and Magnetic Properties

Bilayered diffusion and hydrothermal synthetic methods using pyridine (py) and 2,6-dimethylpyrazine (dmpz) as weak bases and small terminal ligands generated two Cd(II) and Co(II) 1D coordination polymers with dinuclear metal clusters as secondary building units (SBUs) from an organic bridging ligand, 1,1′-biphenyl-3,3′-dicarboxylic acid (H₂ L). They are {[Cd₂(L)₂(py)₄] (py)(CH₃OH)} _n (1) and [Co₂(L)₂(dmpz)₄(H₂O)] _n (2). Compounds 1 crystallizes in the monoclinic space group P2(1)/c, while 2 crystallizes in the triclinic space group P-1. Especially, compound 2 possesses the 1D chain structure that contains two linked left-handed and right-handed helices. Fluorescent measurements for 1 display strong blue light emissions with the maximum emission at 396 nm with the excitation of 320 nm. Magnetization study shows the existence of weak antiferromagnetic coupling for 1 with the negative −E ₂/k value of −1.3 K.     

Delicate structural regulation and stepwise phase transformation of Cu(II) coordination assemblies directed by inorganic counterion

Assembly of 3-(2-pyridyl)-4-(4-pyridyl)-5-(3-pyridyl)-1,2,4-triazole (L²⁴³) with Cu(NO₃)₂ or Cu(ClO₄)₂ affords a mononuclear complex [Cu(L²⁴³)₂(H₂O)₂](NO₃)₂ (1) or a 1D linear coordination polymer {[Cu(L²⁴³)₂(H₂O)](ClO₄)₂(CH₃OH)}_n (3). Incorporating NaN₃ into such assembled systems under similar conditions will produce two distinct 2D layered networks with the formulas {[Cu(L²⁴³)(N₃)](NO₃)(H₂O)₂}_n (2) or {[Cu(L²⁴³)(N₃)](ClO₄)(H₂O)}_n (4), both of which contain dual inorganic-anions as the counterparts (NO₃⁻/N₃⁻ for 2 and ClO₄⁻/N₃⁻ for 4). Further, with a subtle change of reaction condition for 2 or 4, a 1D linear array [Cu(L²⁴³)(N₃)₂]_n (5) is obtained with only N₃⁻ equilibrating the positive charges. Significantly, stepwise structural transformations between such crystalline phases can also be achieved by the direction of azide anion.     

Capturing copper(II) ions using {Cu(tpy)(bpy)} domains

The reaction of 6,6"'-dimethyl-2,2':6',2":6",2'"-quaterpyridine (2) with 2,2':6',2"-terpyridine (tpy) and Cu(NO₃)^·3H₂O leads to the formation of [Cu(tpy)(2)]²⁺ and [Cu₂(tpy)₂(2)]⁴⁺, isolated as the hexafluoridophosphate salts. Single crystal structures of [Cu₂(tpy)₂(2)][PF₆]₄·2H₂O and [Cu(tpy)(2)][PF₆]₂·MeCN are presented and illustrate the special stability of the 5-coordinate {Cu(tpy)(bpy)}²⁺ motif in mono- and dinuclear environments.     

Synthesis, structure and magnetic properties of the first copper(II) complex with an (E)-4-aryl-4-oxo-2-butenoato ligand

A new binuclear Cu(II) complex with an (E)-4-(2,4-diisopropylphenyl)-4-oxo-2-butenoato ligand (L) was successfully synthesized and characterized by elemental analysis and IR-spectroscopy. The structures of (E)-4-(2,4-diisopropylphenyl)-4-oxo-2-butenoic acid (HL), and the corresponding (tetrakis)-μ-[(E)-4-(2,4-diisopropylphenyl)-4-oxo-2-butenoato]-bis(ethanol)-copper(II) complex, [Cu₂L₄(C₂H₅OH)₂], were determined by single crystal X-ray analyses and are preliminarily discussed. This is the first complex of a transition metal with ligand L, as well as the first determined crystal structure of a metal complex with this type of ligand. Analysis of the magnetic susceptibility measurements of the isolated [Cu₂L₄(C₂H₅OH)₂] · H₂O complex shows the existence of a strong anti-ferromagnetic intradimer coupling, with an exchange integral value 2J of −260 cm⁻¹.