New hexaaza macrocyclic binucleating ligands. Oxygen insertion with a dicopper(I) Schiff base macrocyclic complex

Menif, Rached; Martell, Arthur E.; Squattrito, Philip J.; Clearfield, Abraham

doi:10.1021/ic00348a028

Cited by 215 publications

(116 citation statements)

References 0 publications

Supporting

Mentioning

110

Contrasting

Unclassified

Order By: Relevance

“…This reaction has been intensively studied as well, [19,20,21,22] and its relevance to the tyrosinase reaction has been stressed. [23,24] The binucleating ligand contains a bridging xylylene group carrying two arms which provide two nitrogen donors (one imine and one terminal amine) each. On exposure of the Cu I precursor to dioxygen, the central phenylene spacer is hydroxylated, in analogy to the XYL complex (Scheme 1).…”

Section: Introductionmentioning

confidence: 99%

Aromatic Hydroxylation in a Copper Bis(imine) Complex Mediated by a μ‐η²:η² Peroxo Dicopper Core: A Mechanistic Scenario

Sander

Henß

Näther

et al. 2008

Chemistry A European J

View full text Add to dashboard Cite

Detailed mechanistic studies on the ligand hydroxylation reaction mediated by a copper bis(imine) complex are presented. Starting from a structural analysis of the CuI complex and the CuII product with a hydroxylated ligand, the optical absorption and vibrational spectra of starting material and product are analyzed. Kinetic analysis of the ligand hydroxylation reaction shows that O2 binding is the rate-limiting step. The reaction proceeds much faster in methanol than in acetonitrile. Moreover, an inverse kinetic isotope effect (KIE) is evidenced for the reaction in acetonitrile, which is attributed to a sterically congested transition state leading to the peroxo adduct. In methanol, however, no KIE is observed. A DFT analysis of the oxygenation reaction mediated by the micro-eta2:eta2 peroxo core demonstrates that the major barrier after O2 binding corresponds to electrophilic attack on the arene ring. The relevant orbital interaction occurs between the sigma* orbital of the Cu2O2 unit and the HOMO of the ligand. On the basis of the activation energy for the rate-limiting step (18.3 kcal mol(-1)) this reaction is thermally allowed, in agreement with the experimental observation. The calculations also predict the presence of a stable dienone intermediate which, however, escaped experimental detection so far. Reasons for these findings are considered. The implications of the results for the mechanism of tyrosinase are discussed.

show abstract

Section: Introductionmentioning

confidence: 99%

Aromatic Hydroxylation in a Copper Bis(imine) Complex Mediated by a μ‐η²:η² Peroxo Dicopper Core: A Mechanistic Scenario

Sander

Henß

Näther

et al. 2008

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…Nontemplate macrocyclic Schiff base synthesis process requires the use of rigid starting carbonyl groups and high dilution conditions. This process is very efficient and the metal-free product can be obtained in excellent yield [43][44][45][46][47][48][49][50].…”

Section: J Heterocyclic Chem 43 1679 (2006)mentioning

confidence: 99%

Synthesis, complexation and antifungal, antibacterial activity studies of a new macrocyclic schiff base

Uğraş

Başaran

Kılıç

et al. 2006

Journal of Heterocyclic Chem

View full text Add to dashboard Cite

A new macrocyclic ligand, L was synthesized using the high dilution condition with condensation of triethylene glycol diamine and terephtalaldehyde in ethanol. The obtained product, L was identified by FT-IR, 1 H-NMR, 13 C-NMR and Mass spectroscopy. The extraction equilibrium constants were estimated using dichloromethane/water membranes transfer with ICP-AES and AES spectroscopy. Biological studies of this compound was determinated with disc diffusion method. The biological activity results showed that the synthesized ligand L has high activity against the studied microorganisms and high complexation ability against the Fe 2+ cation.

show abstract

“…The macrocyclic ligands 3,6,9,16,19,22-hexaazatricyclo[22.2.2.2 11,14 ]-triaconta-1(27),11 (30),12,14(29),24(28),25-hexaene (H2p), 3,7,11,18, 22,26-hexaazatricyclo[26.2.2.2 13,16 ]tetratriaconta-1(31),13(34), 14,16(33),28(32),29-hexaene (H3p), 3,6,9,16,19,22-hexamethyl-3,6,9,16,19,22-hexaazatricyclo[22.2.2.2 11,14 ]triaconta-1(27),11 (30), 12,14(29),24(28), 6,9,17,20,6,9,17,20,15 ]triaconta-1(29), 11,13,15(30),25,3,7,11,18,22,7,11,18,22,16 ]tetratriaconta-1(31), 13(34),14,16(33), 28(32), 7,11,19,23,7,11,19,23,17 ]tetratriaconta-1(33), 13,15,17(34),29, were prepared according to the published procedures or slight modifications thereof.…”

Section: Materials and Synthesismentioning

confidence: 99%

Synthesis, Structure and Hydrolytic Properties of a Family of New Zn Complexes Containing Hexaazamacrocyclic Ligands

et al. 2004

View full text Add to dashboard Cite

The synthesis, structure and spectroscopic properties of a family of Zn complexes containing a dinucleating hexaazamacrocyclic ligand (L) and anionic ligands (X) of general for-n+ (1−8; L = H2p, H3p, Me2p, Me2m, Me3p, Me3m; X = Cl, n = 0; X = NO 3 , n = 2) have been investigated. The solid-state structural characterisation has been performed by means of X-ray diffraction analysis for complexes 3, 5, 7·1/3CH 2 Cl 2 and 8. The Zn complexes 5, 7·1/ 3CH 2 Cl 2 and 8 containing chloride ligands present a distorted N 2 Cl 2 tetrahedral coordination with two non-coordinated N atoms of the macrocyclic ligand. On the other hand, complex 3, which contains nitrate ligands, displays an N 3 O 2 pentacoordination with all the N atoms of the macrocyclic

show abstract

New hexaaza macrocyclic binucleating ligands. Oxygen insertion with a dicopper(I) Schiff base macrocyclic complex

Cited by 215 publications

References 0 publications

Aromatic Hydroxylation in a Copper Bis(imine) Complex Mediated by a μ‐η²:η² Peroxo Dicopper Core: A Mechanistic Scenario

Aromatic Hydroxylation in a Copper Bis(imine) Complex Mediated by a μ‐η²:η² Peroxo Dicopper Core: A Mechanistic Scenario

Synthesis, complexation and antifungal, antibacterial activity studies of a new macrocyclic schiff base

Synthesis, Structure and Hydrolytic Properties of a Family of New Zn Complexes Containing Hexaazamacrocyclic Ligands

Contact Info

Product

Resources

About

New hexaaza macrocyclic binucleating ligands. Oxygen insertion with a dicopper(I) Schiff base macrocyclic complex

Cited by 215 publications

References 0 publications

Aromatic Hydroxylation in a Copper Bis(imine) Complex Mediated by a μ‐η2:η2 Peroxo Dicopper Core: A Mechanistic Scenario

Aromatic Hydroxylation in a Copper Bis(imine) Complex Mediated by a μ‐η2:η2 Peroxo Dicopper Core: A Mechanistic Scenario

Synthesis, complexation and antifungal, antibacterial activity studies of a new macrocyclic schiff base

Synthesis, Structure and Hydrolytic Properties of a Family of New Zn Complexes Containing Hexaazamacrocyclic Ligands

Contact Info

Product

Resources

About

Aromatic Hydroxylation in a Copper Bis(imine) Complex Mediated by a μ‐η²:η² Peroxo Dicopper Core: A Mechanistic Scenario

Aromatic Hydroxylation in a Copper Bis(imine) Complex Mediated by a μ‐η²:η² Peroxo Dicopper Core: A Mechanistic Scenario