scholarly journals Structural analysis of five-coordinate aluminium(salen) complexes and its relationship to their catalytic activity

2021 ◽  
Author(s):  
Heather Fish ◽  
Sam Hart ◽  
Katie J. Lamb ◽  
Michael North ◽  
Sophie C. Z. Quek ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Structural Analysis ◽  
Trigonal Bipyramidal ◽  
Salen Complexes ◽  
Dynamic Structures ◽  
Salen Ligand

Five-coordinate aluminium(salen) complexes have dynamic structures which interconvert by intramolecular salen ligand rearrangement involving square-based pyramidal and trigonal bipyramidal conformations.

Synthesis and application of Co(salen) complexes containing proximal imidazolium ionic liquid cores

2012 ◽  
Vol 90 (1) ◽  
pp. 60-70 ◽  
Author(s):  
Swapnil Sonar ◽  
Kenson Ambrose ◽  
Arthur D. Hendsbee ◽  
Jason D. Masuda ◽  
Robert D. Singer
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Model Compound ◽  
Veratryl Alcohol ◽  
Oxidation Catalysts ◽  
Imidazolium Ionic Liquid ◽  
Lignin Model Compound ◽  
Salen Complexes ◽  
Lignin Model ◽  
Salen Ligand

Ionic ligands derived from a salen ligand containing two proximal 1,3-disubstituted imidazolium ionic liquid cores form cobalt(III) complexes capable of selectively oxidizing veratryl alcohol, a lignin model compound, to veratraldehyde using air as the source of oxygen. These complexes are easy to prepare, inexpensive, water stable, and soluble in ionic liquids, making them viable candidates for use as oxidation catalysts.

The synthesis, molecular and crystal structure of the 1:1 adduct of triphenyltin chloride with 2,3-diphenylthiazolidin-4-one

1995 ◽  
Vol 73 (1) ◽  
pp. 95-99 ◽  
Author(s):  
Frank E. Smith ◽  
Rosemary C. Hynes ◽  
John Tierney ◽  
Ying Z. Zhang ◽  
George Eng
Keyword(s):  
Crystal Structure ◽  
Structural Analysis ◽  
Oxygen Atom ◽  
Dutch Elm Disease ◽  
Monoclinic Space Group ◽  
Monodentate Ligand ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Triphenyltin Chloride ◽  
Mössbauer Data

The title compound was synthesized as part of an effort to produce a more effective fungicide to combat Dutch Elm Disease (DED), which is caused by the fungus Ceratocystisulmi. A full X-ray structural analysis of the 1:1 adduct has been carried out and the results are reported along with the Mössbauer data for the compound. The crystals are monoclinic, space group P21/a with a = 19.240(3) Å, b = 9.1463(24) Å, c = 19.3512(24) Å, β = 118.874(8)°, V = 2982.0(10) Å3, z = 4, and Dcalc = 1.427 Mg m−3. The final discrepancy factors are RF = 0.056 and Rw = 0.058 for 1915 significant reflections. The QS and IS values in the Mössbauer spectrum of the complex are 3.08 mm s−1 and 1.28 mm s−1, respectively. The 2,3-diphenylthiazolidin-4-one behaves as a monodentate ligand and coordinates to the tin through the oxygen atom. The complex exhibits a trigonal bipyramidal configuration with the three phenyl groups in equatorial positions and the chloride and ligand oxygen occupying the apical sites. Keywords: triorganotin, fungicide, Dutch Elm Disease, thiazolidin-4-one.

Salen ligand complexes as electrocatalysts for direct electrochemical reduction of gaseous carbon dioxide to value added products

RSC Advances ◽  
2015 ◽  
Vol 5 (5) ◽  
pp. 3581-3589 ◽  
Author(s):  
Surya Singh ◽  
Bedika Phukan ◽  
Chandan Mukherjee ◽  
Anil Verma
Keyword(s):  
Carbon Dioxide ◽  
Electrochemical Reduction ◽  
Value Added ◽  
Salen Complexes ◽  
Gaseous Carbon Dioxide ◽  
Salen Ligand ◽  
Centrosymmetric Molecule ◽  
Value Added Products

CO2, being a linear and centrosymmetric molecule, is very stable, and the electrochemical reduction of CO2 requires energy. However, the salen complexes are found to be very efficient to minimize overpotential as compared to their metal counterparts.

scholarly journals Chiral MnIII (Salen) Immobilized on Organic Polymer/Inorganic Zirconium Hydrogen Phosphate Functionalized with 3-Aminopropyltrimethoxysilane as an Efficient and Recyclable Catalyst for Enantioselective Epoxidation of Styrene

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 212 ◽  
Author(s):  
Xiaochuan Zou ◽  
Yue Wang ◽  
Cun Wang ◽  
Kaiyun Shi ◽  
Yanrong Ren ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Supported Catalysts ◽  
Organic Polymer ◽  
Solid Catalyst ◽  
Homogeneous Catalyst ◽  
Hydrogen Phosphate ◽  
Characterization Methods ◽  
Salen Complexes ◽  
Enantioselective Epoxidation ◽  
Better Than

Organic polymers/inorganic zirconium hydrogen phosphate (ZSPP, ZPS-IPPA, and ZPS-PVPA) functionalized with 3-aminopropyltrimethoxysilane were prepared and used to support chiral MnIII (salen) complexes (Jacobsen’s catalyst). Different characterization methods demonstrated that the chiral MnIII (salen) complexes was successfully supported on the surface of the carrier (ZSPP, ZPS-IPPA, or ZPS-PVPA) through a 3-aminopropyltrimethoxysilane group spacer. The supported catalysts effectively catalyzed epoxidation of styrene with m-chloroperbenzoic acid (m-CPBA) as an oxidant in the presence of N-methylmorpholine N-oxide (NMO) as an axial base. These results (ee%, 53.3–63.9) were significantly better than those achieved under a homogeneous counterpart (ee%, 46.2). Moreover, it is obvious that there was no significant decrease in catalytic activity after the catalyst 3 was recycled four times (cons%: from 95.0 to 92.6; ee%: from 64.7 to 60.1). Further recycles of catalyst 3 resulted in poor conversions, although the enantioselectivity obtained was still higher than that of corresponding homogeneous catalyst even after eight times. After the end of the eighth reaction, the solid catalyst was allowed to stand in 2 mol/L of dilute hydrochloric acid overnight, prompting an unexpected discovery that the catalytic activity of the catalyst was recovered again at the 9th and 10th cycles of the catalyst.

Interaction of Metal Ions with 7-Deaza-8-aza-and 8-Aza-purines Preparation and X-Ray Structural Analysis of Copper(II) Complexes

1987 ◽  
Vol 42 (2) ◽  
pp. 195-202 ◽  
Author(s):  
W. S. Sheldrick ◽  
P. Bell
Keyword(s):  
Structural Analysis ◽  
Ph Value ◽  
Pyrimidine Ring ◽  
Polymeric Chain ◽  
Subsequent Formation ◽  
X Ray ◽  
Pyramidal Geometry ◽  
Trigonal Bipyramidal ◽  
Distorted Octahedral ◽  
Hcl Solution

Abstract The reaction of 8-aza-and 7-deaza-8-aza-purines with Cu2+ cations in acid solution has been studied. At a pH value of 2, the 8-azaadenine complex [Cu(H2O)4(AAdH)2](NO3)2 (1), which displays Cu-N9 coordination, may be isolated from solution. The reaction of CuCl2 with 8-aza-hypoxanthine in concentrated HCl solution leads to ring opening at C2 of the azapurine with subsequent formation of dichlorobis[(5-amino-4-carboxamide)[1 - 3]triazole] copper(II) dihydrate 2, in which the triazole ligands display a chelating function, coordinating the metal via N7 and O6. The results for 1 and 2 suggest that copper coordination of the azapurine base is not a prerequisite for opening of the pyrimidine ring. Respectively N9-and N8-coordinated complexes [CUCl3(AllH3)]n 3 and [CuCl2(H2O)(MAllH)]n (4) of allopurinol (AllH2) and 9-methylallopurinol (MAllH) may be prepared by the reaction of CuCl2 with the respective bases in HCl solution. In contrast, with the analogous 1-methyl-4-aminopyrazolo[3,4-d]pyrimidine MAPP, only the salt (MAPPH)4(CU2Cl8) (5) could be isolated under similar conditions, indicating that N8 is less attractive as a binding site in this 7-deaza-8-azaadenine derivative. The structures of 1-5 have been established by X-ray structural analysis. A distorted octahedral [4+2]geometry is found for the copper atoms in 1 and 2. Chlorine bridged polymeric chain structures are adopted by the complexes 3 and 4. An intermediate coordination geometry between trigonal bipyramidal and square-pyramidal is observed for the metal atoms in 3, a distorted square-pyramidal geometry in 4.

Darstellung und Kristallstrukturen von Phenyliodoantimonaten(III). Strukturkorrelation für Halogenoantimonate(III) / Preparation and Crystal Structures of Phenyliodoantimonates(III). Structural Correlation for Haloantimonates(III)

1991 ◽  
Vol 46 (5) ◽  
pp. 639-646 ◽  
Author(s):  
W. S. Sheldrick ◽  
C. Martin
Keyword(s):  
Structural Analysis ◽  
Crystal Structures ◽  
Iodine Atom ◽  
Trans Position ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Structural Correlation ◽  
Bipyramidal Structure ◽  
In Trans

The phenyliodoantimonates(III) [Et4N][Ph2SbI2] (1), [Et4N]2[Ph2Sb2I6] (2) and [Hpy]3[Ph2Sb2I7] (3) have been prepared and their structures established by X-ray structural analysis. The anion [Ph2SbI2]⁻ displays a ψ-trigonal bipyramidal structure with axial Sb–I distances of 2.925(1) and 3.109(1) A. In the dimeric anions [Ph2Sb2I6]2- and [Ph2Sb2I7]3- the antimony atoms exhibit ψ-octahedral geometries. As observed for [Ph2SbI2]⁻, terminal Sb–I bonds in trans-position to one another display significantly different lengths. The anion [Ph2Sb2I7]3- displays Ci- symmetry with a bridging iodine atom at the crystallographic centre of symmetry. Long Sb—I distances of 3.404(1) A are observed to this atom. A structural correlation of opposite Sb–X distances (X = Cl, Br, I) in linear three centre X–Sb ··· X interactions is presented. The sum of the bond valences in iodoantimonates(III) is a minimum for symmetrical I–Sb–I three centre bonds, reflecting thereby the antibonding influence of the Sb 5 s-orbital. This influence is considerably smaller for bromoantimonates(III) and may be effectively neglected for chloroantimonates(III).

scholarly journals Synthesis, Characterisation and Cytotoxic Activity Evaluation of New Metalsalen Complexes Based on the 1,2-bicyclo[2.2.2]octane Bridge

2020 ◽  
Author(s):  
Pierre Milbeo ◽  
François Quintin ◽  
Laure Moulat ◽  
Claude Didierjean ◽  
Jean Martinez ◽  
...  
Keyword(s):  
Cytotoxic Activity ◽  
Ball Mill ◽  
Hct116 Cell ◽  
High Yield ◽  
Cytotoxic Activities ◽  
Salen Complex ◽  
Salen Complexes ◽  
Preparation Route ◽  
The One ◽  
Salen Ligand

Diaminobicyclo[2.2.2]octane was used as starting material for the preparation, in solution or in a ball-mill, of a salen ligand. Five metal salen complexes were prepared in high yield and their cytotoxic activities were evaluated against HCT116 cell lines. Original manganese salen complex displayed the highest activity with a potency 16 fold higher than the one of cisplatin, demonstrating the benefit of the bridging backbone, compared to other salen systems. An alternative preparation route for this complex by mechanochemistry was also performed.<br>

scholarly journals INTRAMOLECULARLY HYPERCOORDINATED ORGANOLEAD COMPOUNDS: (o-MeOC6H4-CH2)PbPh2R, R = Ph, Cl, WITH Pb–O SECONDARY BONDING

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Hemant K. Sharma ◽  
Alejandro J. Metta-Magaña ◽  
Laura I. Saucedo ◽  
Marcela López-Cardoso ◽  
Keith H. Pannell
Keyword(s):  
Structural Analysis ◽  
Organic Ligand ◽  
Phenyl Group ◽  
Group 14 ◽  
Tetrahedral Geometry ◽  
Trigonal Bipyramidal ◽  
Internuclear Distances ◽  
Organolead Compounds ◽  
Oxygen Functionality ◽  
Secondary Bonding

Abstract The tetrahedral geometry of organolead(IV) compounds can be readily transformed by using an organic ligand containing a dangling-arm oxygen functionality. The acidity of the Pb center results in so-called secondary bonding between O and Pb thereby pushing the geometry at Pb toward a trigonal bipyramidal (tbp) structure. Replacing a phenyl group by a chlorine atom dramatically enhances this phenomenon. Thus for (o-methoxybenzyl) triphenyllead (4), and (o-methoxybenzyl)diphenyllead chloride (5), the Pb–O internuclear distances are 3.362(4) and 2.845(3) Å, respectively; 83% (4) and 70% (5) of the sum of the van der Waals Pb and O radii. Within the group 14 element congeners the structural analysis of the (o-methoxybenzyl)triphenylE compounds, E = Si, Ge, Sn, and now Pb, demonstrates the relative acidities of E are Si &lt; Ge &lt; Sn &lt; Pb.

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