Influence of the metal-to-ligand ratio on the formation of metal organic complexes

Dobrzańska, Liliana; Kleinhans, Dewald J.; Barbour, Leonard J.

doi:10.1039/b800720a

Cited by 30 publications

(14 citation statements)

References 38 publications

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“…The crystal structure investigation revealed that, in the solid state, the compound exists as a dimer of formula [Cu(L OHex )Br(μ-Br)] 2 , with the Br(1) ions binding two symmetry-related units to each other. To the best of our knowledge, this complex is one of the few mono- or di-nuclear bis-pyrazolyl acetate copper complexes [ 81 , 82 ] with uncoordinated acetate moieties, and also one of the relatively not-so-abundant copper complexes showing µ-bridging bromide ions coupled with two pentacyclic N-based ligands [ 83 , 84 , 85 , 86 , 87 , 88 ], described in the CCDC repository [ 89 ].…”

Section: Resultsmentioning

confidence: 99%

A New Dimeric Copper(II) Complex of Hexyl Bis(pyrazolyl)acetate Ligand as an Efficient Catalyst for Allylic Oxidations

et al. 2021

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A new dimeric copper(II) bromide complex, [Cu(LOHex)Br(μ-Br)]2 (1), was prepared by a reaction of CuBr2 with the hexyl bis(pyrazol-1-yl)acetate ligand (LOHex) in acetonitrile solution and fully characterized in the solid state and in solution. The crystal structure of 1 was also determined: the complex is interlinked by two bridging bromide ligands and possesses terminal bromide ligands on each copper atom. The two pyrazolyl ligands in 1 coordinate with the nitrogen atoms to complete the Cu coordination sphere, resulting in a five-coordinated geometry—away from idealized trigonal bipyramidal and square pyramidal geometries—which can better be described as distorted square pyramidal, as measured by the τ and χ structural parameters. The pendant hexyloxy chain is disordered over two arrangements, with final site occupancies refined to 0.705 and 0.295. The newly synthesized complex was evaluated as a catalyst in copper-catalyzed C–H oxidation for allylic functionalization through a Kharasch–Sosnovsky reaction without any external reducing agent. Using 0.5 mol% of this catalyst, and tert-butyl peroxybenzoate (Luperox) as an oxidant, allylic benzoates were obtained with up to 90% yield. The general reaction time was only slightly decreased to 24 h but a very significant decrease in the alkene:Luperox ratio to 3:1 was achieved. These factors show relevant improvements with respect to classical Kharasch–Sosnovsky reactions in terms of rate and amount of reagents. The present study highlights the potential of copper(II) complexes containing functionalized bis(pyrazol-1-yl)acetate ligands as efficient catalysts for allylic oxidations.

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Section: Resultsmentioning

confidence: 99%

A New Dimeric Copper(II) Complex of Hexyl Bis(pyrazolyl)acetate Ligand as an Efficient Catalyst for Allylic Oxidations

et al. 2021

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“…In the coordination polymers synthesis, the choice of cluster subunits like organic linkers and metal ions is of very important because it leads to a variety of unusual shapes polymeric frameworks with large gaps, and novel properties [7,8]. Besides the construction of the building units, the network architecture can also rely on the choice of the molar ratios of the molecular components, temperature, pH and solvent [9][10][11].…”

Section: Introductionmentioning

confidence: 99%

“…It is aforethought an appealing type of flexible organic ligand for coordination polymers. [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

1,4-Bis((1H-1,2,4-triazol-1-il)metil)benzen ile Çinko(II) ve Kadmiyum(II) Koordinasyon Polimerlerinin Sentezi ve Karakterizasyonu

Yaman¹,

Erer²,

Yeşılel³

2020

Deu Muhendislik Fakultesi Fen Ve Muhendislik

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Two Zinc(II) and Cadmium(II) coordination polymers, namely [ZnCl2(µ-ptmb)]n (1) and [Cd(µ4-SO4)(µptmb)]n (2) have been obtained with hydrothermal method at 120°C based on flexible ligand 1,4-bis((1H-1,2,4-triazol-1-yl)methyl)benzene (ptmb) in this study. The single-crystal X-ray analyses indicate that complexes 1 and 2 crystallize in the triclinic with P-1 space group and the orthorhombic crystal system with space group Pccn, respectively. In 1, Zn(II) ions display a tetrahedral geometry with two chloride and two ptmb ligands. The ptmb ligand acts to bridge neighboring Zn(II) centres into a 1D zig-zag polymeric chain structures. In 2, Cd(II) ions display octahedral geometry with two ptmb and four different sulfato ligands. Four contiguous Cd(II) ions are bridged through the agency of four sulfato ligands to form a 2D layer. Two adjacent 2D layers further extended into a 3D structure through the bridging ptmb ligands. Besides, the thermal properties of synthesized new complexes have been investigated.

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“…However, up until now, it still remains a considerable challenge to achieve controllable preparation conditions to produce crystalline CP materials with desired topological and chemical attributes. The reason for this stems from the complex formation conditions that influence the self-assembly and crystallization process; the applied synthetic approach is influenced simultaneously by numerous parameters, including the structural characteristics of the organic ligands, the coordination geometry of central metal ions, the metal/ligand molar ratio, available counteranions, the solvent system, the pH value of the solution, temperature, pressure, and reaction time [12–16]. Importantly, the nature of the organic ligand often influences the topology, the stability, the formation, and the crystallization conditions of the resulting hybrid materials.…”

Section: Introductionmentioning

confidence: 99%

Photoluminescent lead(II) coordination polymers stabilised by bifunctional organoarsonate ligands

Lin

Onet

Schmitt

2015

Science and Technology of Advanced Materials

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Four lead(II) coordination polymers were isolated under hydro(solvo)thermal conditions. The applied synthetic methodology takes advantage of the coordination behaviour of a new bifunctional organoarsonate ligand, 4-(1, 2, 4-triazol-4-yl)phenylarsonic acid (H2TPAA) and involves the variation of lead(II) reactants, metal/ligand mole ratios, and solvents. The constitutional composition of the four lead(II) coordination polymers can be formulated as [Pb2(TPAA)(HTPAA)(NO3)]·6H2O (1), [Pb2(TPAA)(HTPAA)2]·DMF·0.5H2O (DMF = N, N-Dimethylformamide) (2), [Pb2Cl2(TPAA)H2O] (3), and [Pb3Cl(TPAA)(HTPAA)2H2O]Cl (4). The compounds were characterized by single-crystal and powder x-ray diffraction techniques, thermogravimetric analyses, infra-red spectroscopy, and elemental analyses. Single-crystal x-ray diffraction reveals that 1 and 2 represent two-dimensional (2D) layered structures whilst 3 and 4 form three-dimensional (3D) frameworks. The structures of 1, 2, and 4 contain one-dimensional (1D) {PbII/AsO3} substructures, while 3 is composed of 2D {PbII/AsO3} arrays. Besides their interesting topologies, 1–4 all exhibit photoluminescence properties in the solid state at room temperature.

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Influence of the metal-to-ligand ratio on the formation of metal organic complexes

Cited by 30 publications

References 38 publications

A New Dimeric Copper(II) Complex of Hexyl Bis(pyrazolyl)acetate Ligand as an Efficient Catalyst for Allylic Oxidations

A New Dimeric Copper(II) Complex of Hexyl Bis(pyrazolyl)acetate Ligand as an Efficient Catalyst for Allylic Oxidations

1,4-Bis((1H-1,2,4-triazol-1-il)metil)benzen ile Çinko(II) ve Kadmiyum(II) Koordinasyon Polimerlerinin Sentezi ve Karakterizasyonu

Photoluminescent lead(II) coordination polymers stabilised by bifunctional organoarsonate ligands

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