Anion-triggered coordination mode of the new chelating ligand 1,3-bis[5-(2-pyrimidinyl)-1,2,4-triazol-3-yl]propane

Polyhedron ◽  
2015 ◽  
Vol 85 ◽  
pp. 525-529 ◽  
Author(s):  
Alexey N. Gusev ◽  
Victor F. Shul’gin ◽  
Eziz Beyjyyev ◽  
Grigory G. Alexandrov ◽  
Igor L. Eremenko ◽  
...  
Keyword(s):  
Coordination Mode ◽  
Chelating Ligand

How to force a classical chelating ligand to a metal non-chelating bridge: the observation of a rare coordination mode of diethanolamine in the 1D complex {[Cu2(Piv)4(H3tBuDea)](Piv)}n

CrystEngComm ◽  
2014 ◽  
Vol 16 (5) ◽  
pp. 775-783 ◽  
Author(s):  
Oksana V. Nesterova ◽  
Marina V. Kirillova ◽  
M. Fátima C. Guedes da Silva ◽  
Roman Boča ◽  
Armando J. L. Pombeiro
Keyword(s):  
Coordination Mode ◽  
Chelating Ligand ◽  
1D Complex

Synthesis, Characterization and Biological Activity of Nitrogen­ Oxygen-Sulfur (NOS) Transition Metal Complexes Derived from Novel S-2,4-dichlorobenzyldithiocarbazate with 5-fluoroisatin

2010 ◽  
Vol 7 (2) ◽  
pp. 67
Author(s):  
Mohd Abdul Fatah Abdul Manan ◽  
Hadariah Bahron ◽  
Karimah Kassim ◽  
Mohd Asrul Hafaz Mohamad ◽  
Syed Nazmi Sayed Mohamad
Keyword(s):  
Bacillus Subtilis ◽  
Schiff Base ◽  
Metal Complexes ◽  
Condensation Reaction ◽  
Schiff Base Complex ◽  
Inhibition Zone ◽  
Azomethine Nitrogen ◽  
Strong Activity ◽  
Chelating Ligand ◽  
Physico Chemical

A novel Schiff base containing nitrogen-oxygen-sulfur (NOS) donor atoms formed from the condensation reaction of S-2,4-dichlorobenzyldithiocarbazate (S-2,4BDTC) with 5-fluroisatin has been synthesized. Complexes of cobalt(II), nickel(II), copper(II), zinc(II) and cadmium(II) with this Schiff base have been prepared and characterized using elemental analysis and various physico-chemical techniques. In the cobalt(II) and nickel(II) complexes the Schiff base behaves as a uninegatively charged tridentate nitrogen-oxygen-sulfur (NOS) chelating ligand, bonding through the azomethine nitrogen, thiolate sulfur and carbonylic oxygen of the isatin moiety. However, in the copper(II), zinc(II) and cadmium(II) complexes the Schiff base behaves as a nitrogen-sulfur (NS) bidentate chelating ligand, bonding through the azomethine nitrogen and thiolate sulfur. The Schiff base and the metal complexes were evaluated with respect to antimicrobial activity, which was performed in relation to two selected pathogenic microbials (Bacillus subtilis and Pseudomonas aeruginosa). It was observed that only the zinc Schiff base complex exhibited strong activity against the Bacillus subtilis bacteria with an inhibition zone of 25 mm. 

Synthesis, Characterization and Biological Activity of NitrogenOxygen-Sulfur (NOS) Transition Metal Complexes Derived from Novel S-2,4-dichlorobenzyldithiocarbazate with 5-fluoroisatin

2010 ◽  
Vol 7 (2) ◽  
pp. 67
Author(s):  
Mohd Abdul Fatah Abdul Manan ◽  
Hadariah Bahron ◽  
Karimah Kassim ◽  
Mohd Asrul Hafiz Muhamad ◽  
Syed Nazmi Sayed Mohamad
Keyword(s):  
Bacillus Subtilis ◽  
Schiff Base ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Condensation Reaction ◽  
Inhibition Zone ◽  
Azomethine Nitrogen ◽  
Strong Activity ◽  
Chelating Ligand ◽  
Physico Chemical

A novel Schiff base containing nitrogen-oxygen-sulfur (NOS) donor atoms formed from the condensation reaction of S-2,4- dichlorobenzyldithiocarbazate (S-2.4BDTC) with 5-fluroisatin has been synthesized. Complexes of cobalt(ll), nickel(ll), copper(ll), zinc(ll) and cadmium(ll) with this Schiff base have been prepared and characterized using elemental analysis and various physico-chemical techniques. In the cobalt(ll) and nickel(II) complexes the SchifJbase behaves as a uninegatively charged tridentate nitrogen-oxygen-sulfur (NOS) chelating ligand, bonding through the azomethine nitrogen, thiolate sulfur and carbonylic oxygen of the isatin moiety. However. in the copper(ll), zinc(II) and cadmium(II) complexes the Schiff base behaves as a nitrogen-sulfur (NS) bidentate chelating ligand, bonding through the azomethine nitrogen and thiolate sulfur. The Schiff base and the metal complexes were evaluated with respect to antimicrobial activity, which was performed in reallion to two selected pathogenic microbials (Bacillus subtilis and Pseudomonas aeruginosa). It was observed that only the zinc Schiffbase complex exhibited strong activity against the Bacillus subtilis bacteria with an inhibition zone of25 mm.

Nickel(II)-Methyl Complexes Adopting Idealized Seesaw Geometries

2019 ◽  
Author(s):  
Ethan A. Hill ◽  
Norman Zhao ◽  
Alexander S. Filatov ◽  
John Anderson
Keyword(s):  
Singlet State ◽  
Strong Field ◽  
Structural Distortion ◽  
Computational Results ◽  
Threefold Symmetry ◽  
Chelating Ligand ◽  
Electronic Stabilization

We report four-coordinate nickel(II)-methyl complexes of tris-carbene borate ligands which adopt rare seesaw geometries. Experimental and computational results suggest the structural distortion from threefold symmetry results from a combination of electronic stabilization of the singlet state, strong field donors, and constrained angles from the chelating ligand.

A novel coordination mode for dithiatetrazocines: preparation, x-ray structure, and fluxional behavior of [Pt(PPh3)(1,5-Ph4P2N4S2)]2

1990 ◽  
Vol 29 (17) ◽  
pp. 3068-3069 ◽  
Author(s):  
Tristram Chivers ◽  
Mark Edwards ◽  
Pramesh N. Kapoor ◽  
Auke Meetsma ◽  
Johan C. Van de Grampel ◽  
...  
Keyword(s):  
Coordination Mode ◽  
X Ray

scholarly journals The Role of the Disulfide Bridge in the Copper (II) Binding by the Cyclic His4-Peptide

2021 ◽  
Vol 22 (12) ◽  
pp. 6458
Author(s):  
Aleksandra Pieniężna ◽  
Weronika Witak ◽  
Aneta Szymańska ◽  
Justyna Brasuń
Keyword(s):  
Metal Ions ◽  
Coordination Mode ◽  
Transition Metal Ions ◽  
Disulfide Bridge ◽  
Chain Flexibility ◽  
Vis Spectroscopy ◽  
Ph Range ◽  
Cd Studies ◽  
Metal Ratios

In this paper, we present studies on the influence of the disulfide bridge on the copper (II) ions’ binding abilities by the cyclic His4-peptide. The studied ligand HKHPHRHC-S-S-C consists of nine amino acids. The cyclic structure was obtained through a disulfide bridge between two cysteinyl groups. Moreover, this peptide is characterized by the presence of four His residues in the sequence, which makes it an interesting ligand for transition metal ions. The potentiometric and spectroscopic (UV-Vis spectroscopy and circular dichroism spectroscopy (CD)) studies were carried out in various molar ligand to metal ratios: 2:1, 1:1, and 1:2, in the pH range of 2.5–11 at 25 °C. The results showed that the cyclic His4-peptide promotes dinuclear complexes in each of these systems and forms the final dinuclear species with the {NIm, 3N-amide}{NIm, 3N-amide} coordination mode. The obtained data shows that cyclization by the formation of the disulfide bond has an impact on the peptide chain flexibility and appearance of additional potential donors for metal ions and influences the copper (II) ions’ coordination.

A 4-acyl-5-pyrazolone ligand (HQ) in N-unidentate coordination mode in a Rh(CO)2Cl(HQ)-type complex

2004 ◽  
Vol 7 (2) ◽  
pp. 235-237 ◽  
Author(s):  
Augusto Cingolani ◽  
Fabio Marchetti ◽  
Claudio Pettinari ◽  
Riccardo Pettinari ◽  
Brian W. Skelton ◽  
...  
Keyword(s):  
Coordination Mode ◽  
Type Complex

scholarly journals Iron(II) complexes of dimethyltriazacyclophane

2018 ◽  
Vol 74 (12) ◽  
pp. 1641-1649
Author(s):  
Wei-Tsung Lee ◽  
Matthias Zeller ◽  
David Upp ◽  
Yuliya Politanska ◽  
Doug Steinman ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Dft Calculations ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Coordination Mode ◽  
Functional Theory ◽  
Metal Centers ◽  
Bonding Interaction

Treatment of the ortho-triazacyclophane 1,4-dimethyltribenzo[b,e,h][1,4,7]triazacyclonona-2,5,8-triene [(C6H5)3(NH)(NCH3)2, L1] with Fe[N(SiMe3)2]2 yields the dimeric iron(II) complex bis(μ-1,4-dimethyltribenzo[b,e,h][1,4,7]triazacyclonona-2,5,8-trien-7-ido)bis[(μ-1,4-dimethyltribenzo[b,e,h][1,4,7]triazacyclonona-2,5,8-trien-7-ido)iron(II)], [Fe(C20H18N3)4] or Fe2(L1)4 (9). Dissolution of 9 in tetrahydrofuran (THF) results in solvation by two THF ligands and the formation of a simpler monoiron complex, namely bis(μ-1,4-dimethyltribenzo[b,e,h][1,4,7]triazacyclonona-2,5,8-trien-7-ido-κN 7)bis(tetrahydrofuran-κO)iron(II), [Fe(C20H18N3)2(C4H8O)2] or (L1)2Fe(THF)2 (10). The reaction is reversible and 10 reverts in vacuo to diiron complex 9. In the structures of both 9 and 10, the monoanionic triazacyclophane ligand L1− is observed in only the less-symmetric saddle conformation. No bowl-shaped crown conformers are observed in the solid state, thus preventing chelating κ3-coordination to the metal as had been proposed earlier based on density functional theory (DFT) calculations. Instead, the L1− ligands are bound in either a η2-chelating fashion through the amide and one amine donor (for one of the four ligands of 9), or solely through their amide N atoms in an even simpler monodentate η1-coordination mode. Density functional calculations on dimer 9 revealed nearly full cationic charges on each Fe atom and no bonding interaction between the two metal centers, consistent with the relatively long Fe...Fe distance of 2.912 (1) Å observed in the solid state.

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