Tridentate Bridging Research Articles

Tetrakis(μ2-2-phenoxypropionato)-κ3O,O′:O′;κ3O:O,O′;κ4O:O′-bis[(1,10-phenanthroline-κ2N,N′)(2-phenoxypropionato-κ2O,O′)cerium(III)

In the centrosymmetric binuclear title complex, [Ce2(C9H9O3)6(C12H8N2)2], the two CeIII ions are linked by four 2-phen­oxy­propionate groups in bi- and tridentate bridging modes. Each CeIII ion is nine-coordinated by one 1,10-phenanthroline mol­ecule, two O atoms from a chelating carboxyl­ate, two O atoms derived from a μ3-carboxylate and two O atoms derived from two μ2-carboxylate ligands in a distorted CeN2O7 monocapped square-anti­prismatic geometry.

Tetrakis(μ2-2-phenoxypropionato)-κ3O,O′:O′;κ3O:O,O′;κ4O:O′-bis[(1,10-phenanthroline-κ2N,N′)(2-phenoxypropionato-κ2O,O′)gadolinium(III)

In the centrosymmetric binuclear title complex, [Gd2(C9H9O3)6(C12H8N2)2], the two Gd(III) ions are linked by four 2-phen­oxy­propionate (L) groups in bi- and tridentate bridging modes. Each GdIII ion is nine-coordinated by one 1,10-phenanthroline mol­ecule, one bidentate chelating carboxyl­ate group and four bridging carboxyl­ate groups in a distorted GdN2O7 monocapped square-anti­prismatic geometry.

Tetrakis(μ2-2-phenoxypropionato)-κ3O,O′:O′;κ3O:O,O′;κ4O:O′-bis[(1,10-phenanthroline-κ2N,N′)(2-phenoxypropionato-κ2O,O′)lanthanum(III)

In the centrosymmetric binuclear title complex, [La2(C9H9O3)6(C12H8N2)2], the two La(III) ions are linked by four 2-phen­oxy­propionate (L) groups in bi- and tridentate bridging modes. Each LaIII ion is nine-coordinated by one 1,10-phenanthroline mol­ecule, one bidentate chelating carboxyl­ate group and four bridging carboxyl­ate groups in a distorted LaN2O7 monocapped square-anti­prismatic geometry.

Tetrakis(μ-2-phenoxypropionato)-κ3O,O′:O′;κ3O:O,O′,κ4O:O′-bis[(1,10-phenanthroline-κ2N,N′)(2-phenoxypropionato-κ2O,O′)praseodymium(III)

In the centrosymmetric binuclear title complex, [Pr2(C9H9O3)6(C12H8N2)2], the two PrIII ions are linked by four 2-phen­oxy­propionate (L) groups through their bi- and tridentate bridging modes. Each PrIII ion is nine-coordinated by one 1,10-phenanthroline mol­ecule, one bidentate carboxyl­ate group and four bridging carboxyl­ate groups in a distorted PrN2O7 monocapped square-anti­prismatic geometry. The title compound is isotypic with its terbium- and dysprosium-containing analogues.

Tetrakis(μ-2-phenoxypropionato)-κ3O,O′:O′;κ3O:O,O′,κ4O:O′-bis[(1,10-phenanthroline-κ2N,N′)(2-phenoxypropionato-κ2O,O′)dysprosium(III)

In the centrosymmetric binuclear title complex, [Dy2(C9H9O3)6(C12H8N2)2], the two DyIII ions are linked by four 2-phen­oxy­propionate (L) groups through their bi- and tridentate bridging modes. Each DyIII ion is nine-coordinated by one 1,10-phenanthroline mol­ecule, one bidentate carboxyl­ate group and four bridging carboxyl­ate groups in a distorted DyN2O7 monocapped square-anti­prismatic geometry. The title compound is isotypic with its terbium-containing analogue.

Immobilization, Trapping, and Anion Exchange of Perrhenate Ion Using Copper-Based Tripodal Complexes

We describe a multidentate tripodal ligand in which three pendant arms carrying di(2-picolyl)amine units are linked to the ortho positions of a tris(o-xylyl) scaffold, providing N(CH(2)-o-C(6)H(4)CH(2)N(CH(2)py)(2))(3) (L). Reaction of L with CuCl(2) in the presence of hexafluorophosphate anion afforded blue cubes of [(CuCl)(3)L](PF(6))(3)·5H(2)O (1). Crystallographic studies of 1 revealed that the three symmetry-related arms each coordinate a {Cu(II)Cl} unit, and two molecules of 1 are connected to one another through a Cu(μ-Cl)(2)Cu bridge, extending the molecular structure to form a two-dimensional (2-D) layer. These 2-D layers pack in an ABCABC... fashion with PF(6)(-) anions located in between. Reaction of 1 with a stoichiometric amount of perrhenate ion afforded blue plates of [(CuCl)(3)L](PF(6))(ReO(4))(2)·3H(2)O (2). Compound 2 has the same lattice structure as 1, but the tricopper unit backbone now traps one ReO(4)(-) anion through Coulombic interactions. In addition, three molecules of 2 are bridged by a perrhenate ion, forming a Cu(3)(μ(3)-ReO(4)) cluster, to give a different 2-D structure displaying a rare tridentate bridging ReO(4)(-) mode. Thus, in addition to classic perrhenate trapping through weak Coulombic interactions, 2 represents an exceptional example in which the ReO(4)(-) anion is immobilized in an extended framework through tight covalent interactions. The interlamellar PF(6)(-) anions in 1 can be exchanged with other anions including perrhenate, perchlorate, or periodate. The structural similarity between perrhenate and pertechnetate makes these materials of potential interest for pertechnetate trapping.

Magnetic property of a triply bridged linear trinuclear nickel complex

A new linear trinuclear nickel(II) complex, [Ni 3L 2(OCn) 4] (HL = 2-[(3-dimethylamino-propylimino)-methyl]-phenol, OCn = cinnamate), with phenoxo bridge and a novel tridentate bridging mode (in a 2.21 fashion according to Harris notation), of the cinnamate ligand has been synthesized and characterized by IR spectroscopy, UV–Vis spectroscopy, X-ray crystallography and static magnetic measurements. The molecular structure shows that each nickel ion occupies octahedral coordinating geometry. Apart from the phenoxo bridges, the carboxylic group of cinnamic anion shows two types of bridging modes viz. 2.11 and 2.21. The magnetic data indicate that a moderate intramolecular ferromagnetic and a weak intermolecular antiferromagnetic interaction are present in the complex under study. Broken symmetry density functional theory has been used to estimate the sign and magnitude of the coupling constants to understand the magnetic exchange mechanisms of the present system. The relative abilities of different bridging groups to mediate magnetic exchange interactions between paramagnetic nickel centers have been investigated by DFT calculation with variable angles. The results show that a small change in phenoxo-bridging angle has a very strong impact on the magnetic properties.

Tetrakis(μ-2-phenoxypropionato)-κ3O,O′:O′;κ3O:O,O′;κ4O:O′-bis[(1,10-phenanthroline-κ2N,N′)(2-phenoxypropionato-κ2O,O′)terbium(III)

In the centrosymmetric binuclear title complex, [Tb2(C9H9O3)6(C12H8N2)2], the two TbIII ions are linked by four 2-phen­oxy­propionate (L) groups through their bi- and tridentate bridging modes. Each TbIII ion is nine-coordinated by one 1,10-phenanthroline mol­ecule, one bidentate carboxyl­ate group and four bridging carboxyl­ate groups in a distorted TbN2O7 monocapped square-anti­prismatic geometry.

A photoluminescent dinuclear silver(I) complex exhibits CH···Ag close interactions and a new coordination mode of the pyridine-2,3-dicarboxylate

Abstract In this study, a novel dinuclear Ag(I)-pyridine-2,3-dicarboxylate complex with 1,3-diaminopropane ligand (pda), [Ag2(μ-2,3-pydc)2(Hpda)2]⋅2H2O (H22,3-pydc = pyridine-2,3-dicarboxylic acid), has been synthesized. The molecular structure of complex has been determined by the single crystal X-ray diffraction. The complex has been observed to crystallize in the triclinic space group P-1. The Ag(I) ion exhibits a distorted trigonal pyramidal geometry by two 2,3-pydc and one protonated monodentate Hpda ligands. The 2,3-pydc ligand acts as a tridentate bridging ligand with a new coordination mode between two Ag(I) centers through the pyridine N and carboxyl μ-O atoms, forming a 4-membered parallelogram Ag2O2 ring. The most striking feature is that the structure contains both intra- and inter-molecular C H···Ag hydrogen bonding interactions to form infinite 1D chains containing R22(8) rings.

Di-μ-benzoato-κ3O,O′:O′;κ3O:O,O′-bis[(benzoato-κ2O,O′)(1,10-phenanthroline-κ2N,N′)cadmium

The dinuclear title compound, [Cd2(C7H5O2)4(C12H8N2)2], lies on a crystallographic twofold axis. The CdII ions are connected by two bridging benzoate anions and each ion is seven-coordinated by five O atoms from three benzoate ligands and by two N atoms from 1,10-phenanthroline. The benzoate ligands adopt two different coordination modes, acting as bidentate and bridging tridentate ligands. The discrete neutral mol­ecules further extend their structure into a three-dimensional supra­molecular framework by inter­molecular π–π [inter­planar distances of 3.392 (4) Å] and C—H⋯π stacking inter­actions [H–mean plane = 2.567 (4) and 2.781 (4) Å].

Catena-Poly[[[(di-2-pyridylamine-κ2N2,N2′)copper(II)]-μ-benzene-1,3-dicarboxylato-κ3O1,O1′:O3] monohydrate], a zigzag coordination polymer with strong π–π interactions

The novel title coordination polymer, {[Cu(C(8)H(4)O(4))(C(10)H(9)N(3))]·H(2)O}(n), synthesized by the slow-diffusion method, takes the form of one-dimensional zigzag chains built up of Cu(II) cations linked by benzene-1,3-dicarboxylate (ipht) anions. An exceptional characteristic of this structure is that it belongs to a small group of metal-organic polymers where ipht is coordinated as a bridging tridentate ligand with monodentate and chelate coordination of individual carboxylate groups. The Cu(II) cation has a highly distorted square-pyramidal geometry formed by three O atoms from two ipht anions and two N atoms from a di-2-pyridylamine (dipya) ligand. The zigzag chains, which run along the b axis, further construct a three-dimensional metal-organic framework via strong face-to-face π-π interactions and hydrogen bonds. A solvent water molecule is linked to the different carboxylate groups via hydrogen bonds. Thermogravimetric and differential scanning calorimetric analyses confirm the strong hydrogen bonding.

Anion-mediated self-assembly: Five Cd(ІІ) coordination aggregates with a mercaptotetrazole ligand

Five Cd(II) complexes, {[Cd 4(MTZ) 2(H 2O) 2Cl 8]·0.5H 2O} n ( 1), [Cd(MTZ) 2Br 2] ( 2), [Cd 2(MTZ) 2I 4] ( 3), [Cd 2(MTZ) 2(H 2O) 8] (SO 4) 2 ( 4), {[Cd(MTZ) 2(H 2O) 2](ClO 4) 2} n ( 5), based on different anions with the mercaptotetrazole ligand MTZ (MTZ = 1-(2-dimethylamino-ethyl)-5-mercapto-1H-tetrazole) have been synthesized. Employment of different anions can result in structural diversity in 1– 5. In 1, the Cd(II) ions make use of μ 2-Cl, μ 3-Cl bridging each other to form a novel Cd 4Cl 8 inorganic network structure. On the other hand, the 2D structure is further stabilized by MTZ as a tridentate bridging organic ligand holding three adjacent Cd(II) ions. In 2, MTZ as a terminal ligand coordinates with a Cd(II) ion to form a mononuclear structure. As a μ 2, η 2 bridging ligand, MTZ links Cd(II) ions to form a dimeric structures in 3 and 4, and a 1D infinite chain in 5. In addition, the luminescent properties of 1– 5 have been investigated in the solid state at room temperature.

Di-μ-benzoato-κ3O,O′:O;κ3O:O,O′-bis[(benzoato-κ2O,O′)(1,10-phenanthroline-κ2N,N′)lead(II)

In the centrosymmetric dinuclear title compound, [Pb2(C7H5O2)4(C12H8N2)2], two Pb2+ ions are connected by two tridentate bridging benzoate anions. The Pb2+ ion is seven-coordinated by five O atoms from three benzoate anions and two N atoms from the 1,10-phenanthroline ligands. The benzoate anions adopt two different coordination modes, one bidentate–chelating and one tridentate bridging–chelating. The three-dimensional supra­molecular framework is achieved by inter­molecular π–π stacking inter­actions, with a shortest centroid–centroid distance of 3.617 (4) Å.

Syntheses, structures and luminescent properties of lanthanide complexes with 6-hydroxynicotinic acid

Two types of novel lanthanide complexes with the 6-hydroxynicotinic acid (OHnicH) {[Ln(OHnic)(Onic)(H2O)5·(OHnicH)]·H2O}n [Ln=La(1), Ce(2), Gd(3)] and {[Ln(OHnic)3(H2O)]·3H2O}n [Ln=La(4), Pr(5)] have been synthesized and characterized by elemental analyses, IR spectra, UV absorption spectra and single crystal X-ray diffraction. The structures of the as-prepared complexes vary with the different coordination modes of the ligands. In complexes 1–3, the adjacent metal centers are linked by the chelating-bridging tridentate modes of the ligands to form 1D chains; while in 4 and 5, the adjacent metal ions are bridged by the ligands in the chelating-bridging bidentate modes to form dinuclear units, then linked into 1D chains through the ligands in the bridging bidentate modes, and further linked to form 2D plane structures via the bridging tridentate modes of the ligands. Thermostabilities and luminescent properties of the complexes have been discussed in detail.

Synthesis, crystal structure and properties of a samarium nitrate complex with 2-idobenzoic acid and 2,2'-bipyridine

A complex [Sm(2-IBA) 2(2,2'-bipy)(NO 3)] 2 (2-HIBA=2-idobenzoic acid; 2,2'-bipy=2,2'-bipyridine) was synthesized by solvent method and characterized by X-ray single-crystal diffraction. The complex crystallized in triclinic crystal system, Pi space group, with a= 0.97873(3) nm, b=1.28124(3) nm, c=1.29174(3) nm, a=108.3740(10)°, β=111.7340(10)°, γ=101.7870(10)°. The complex was the centrosymmetric binuclear molecule, in which two Sm 3+ ions were connected by four 2-IBA ligands. Two of the 2-IBA ligands were in a bidentate bridging mode and the other two were in a tridentate bridging mode. Sm 3+ ion was also coordinated to one chelating NO 3 − group and one 2,2'-bipy molecule. The 2D supramolecular network formed through weak I…I interactions and p…p stacking interactions. The fluorescent emission peaks at 562, 595, and 642 nm corresponded to the 4G 5/2→ 6F 5/2, 4G 5/2→ 6F 7/2, and 4G 5/2→ 6F 9/2 transitions of Sm 3+ ion, respectively.

Synthesis, crystal structure, supramolecular assembly, and thermal stability of two new lanthanide coordination polymers based on α-naphthoxyacetate

Two new lanthanide coordination polymers [Ln(noa)3(H2O)2] [Ln = Pr (1) and Nd (2), noa = α-naphthoxyacetate] have been synthesized under hydrothermal conditions and characterized by X-ray crystallography, IR spectra, and thermal analysis. In the crystal structure, adjacent Ln(III) ions were connected each other by tridentate bridging noa anions to form a one-dimensional (1D) chain-like structure. Moreover, the 1D chains were further linked together via hydrogen bonds and π–π attractions, resulting in an extended two-dimensional (2D) supramolecular network. The noa ligands adopted two different coordination modes, namely, chelating and tridentate bridging.

ChemInform Abstract: Monomeric and Dimeric Erbium(III) Complexes. Crystal Structure and Photoluminescence Studies

AbstractReview: 42 refs.

Coordination compound of cadmium acetate with the condensation product of salicylaldehyde and 3-(pyridin-2-yl)-5-(2-aminophenyl)-1H-1,2,4-triazole

The cadmium(II) complex with the condensation product of salicylaldehyde and 3-(pyridine-2-yl)-5-(2-aminophenyl)-1H-1,2,4-triazole (H2L), Cd2(H2L)2(OAc)4 · 3EtOH, is synthesized. Its crystal structure is studied by X-ray diffraction analysis. In the centrosymmetric binuclear complex (Cd…Cd 3.938(1)A), the Cd atoms are bonded by two tridentate bridging acetate anions. Two other acetate anions are terminal and coordinated by the monodentate mode. The coordination polyhedron of the Cd atom is a distorted octahedron. The triazole ligands are bonded to the cadmium cations through the N atoms of the pyridine cycle and triazole ring.

μ-2-(4-Hy-droxy-phen-yl)acetato]-κO:O,O';κO,O':O'-bis-{aqua-(4,4'-bi-pyridine-κN)bis-[2-(4-hy-droxy-phen-yl)acetato-κO,O']holmium(III)} mono-hydrate.

In the title dinuclear complex, [Ho2(C8H7O3)6(C10H8N2)2(H2O)2]·H2O, each of the two independent HoIII ions is coordinated by eight O atoms from four 4-hy­droxy­phenyl­acetate (HPAA) ligands and a water mol­ecule, and one N atom from a 4,4′-bipyridine (bipy) ligand in a distorted tricapped trigonal–prismatic geometry. The HPAA ligands are coordinated in bis-chelate, bridging and bridging tridentate modes. In the crystal, O—H⋯O and O—H⋯N hydrogen bonds link the mol­ecules into a three-dimensional network.

Supramolecular architectures of cadmium(ii)-orotate complexes containing water clusters

Three novel cadmium(II) complexes containing orotate ligand have been synthesized under different pH and characterized by X-ray crystallography, IR spectroscopy and thermal analyses measurements. In the complexes, the orotate ligand exhibits three different coordination modes. In [Cd2(μ-HOr)2(H2O)4(NH3)2]·2H2O (1), the orotate acts as a tridentate ligand, showing unprecedented coordination mode. The (NH4)2[Cd3(μ-HOr)2(HOr)2(H2O)8]·4H2O (2) is constructed from orotate acting as both bidentate and tridentate bridging ligands. The Cd1 and Cd2 ions have two different coordination environments with four HOr, eight aqua ligands. Furthermore, 2 exhibits the novel 2D metal–water cluster layers. The (Hcha)4[Cd(HOr)2(H2O)(cha)][Cd(HOr)2(H2O)2]·H2O (3) (cha = cyclohexylamine, H3Or = orotic acid) consists of discrete cis and trans anionic complexes. The cha molecules exhibit chemically different functions by coordinating to Cd(II) ion in one form and being protonated and acting as counter–ions in other form. In the complexes, the supramolecular networks are constructed by novel N–H⋯O strong hydrogen bonds to form DA:AD motif, CO⋯π and π⋯π interactions.