Macrocycle Formation by Proton-Template-Induced Dimerization of Complexes with (Alkoxoimino)pyridine

Álvarez, Celedonio M.; García‐Rodríguez, Raúl; Martín‐Alvarez, José M.; Miguel, Daniel; Turiel, José A.

doi:10.1021/ic300196w

Cited by 9 publications

(5 citation statements)

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“…As previously demonstrated in our work18–20 and in the work of Miguel et al,46–48 chelating aldehydes readily react with primary amines in the presence of [Re(CO) 5 X] to afford the corresponding Schiff base compounds (Scheme ). For example, mononuclear Re I complexes 1 and 2 were synthesized by using this method for use as controls in this study.…”

Section: Resultssupporting

confidence: 77%

The Synthesis of Dimeric Re^I–Phenylenediimine Conjugates: Spectroscopic and Electrochemical Studies

et al. 2014

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A series of dimeric ReI(CO)3 compounds have been prepared by means of a one‐pot reaction of [Re(CO)5X] (X = Cl, Br), pyridine‐2‐carboxyaldehyde, and o‐, m‐, or p‐phenylenediamine. For the m‐ and p‐substituted phenylenediamine reactions, phenyl‐bridged bis(pyridine‐2‐carbaldimine) compounds of the formula [Re(CO)3X]2(μ‐PPC) [3–7; X = Cl, Br; μ‐PPC = m‐ or p‐phenylene bis(pyridine‐2‐carbaldimine)] were produced, with m‐phenylenediamine forming a mixture of isomers. For reactions with o‐phenylenediamine, multiple products formed (compounds 8–11), which ranged from the desired o‐phenylene bis(pyridine‐2‐carbaldimine) adduct to 2‐pyridylbenzimidazole and bridging dipyridinylquinoxaline complexes. An example of each complex was structurally elucidated by single‐crystal X‐ray methods. The dimeric m‐ and p‐phenylene‐bridged Re(CO)3X compounds, including a sulfonate derivative designed to improve solubility, were investigated for possible photophysical applications through the use of UV/Vis spectroscopy and cyclic voltammetry; the study revealed coupling between the rhenium centers.

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Section: Resultssupporting

confidence: 77%

The Synthesis of Dimeric Re^I–Phenylenediimine Conjugates: Spectroscopic and Electrochemical Studies

et al. 2014

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“…A variety of experimental and theoretical studies have been carried out to probe the effects of dimer structure on physical properties, such as photophysics or electron transfer. 3,[8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] Under certain conditions, Re(CO) 3 complex centers can couple through a bridging ligand. Parameters including bridge type, metal-metal distance, interplanar distances, degree of saturation, conjugation, and orientation of the bridge moiety can all affect the degree of coupling and their resultant properties such as redox potentials.…”

Section: Introductionmentioning

confidence: 99%

Hydrazine-mediated strongly coupled Re(CO)₃dimers

et al. 2015

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Dimeric metal complexes can often exhibit coupling interactions via bridging ligands. In this report, we present two Re(CO)3 dimers, where the metals are linked via a bis(pyca) hydrazine (pyca = pyridine-2-carbaldehyde imine) Schiff base ligand. For the dimeric compounds 4 and 5, we observe strong coupling across the dimer as measured by cyclic voltammetry: ∼480 mV separations between the first and the second reduction waves that correspond to comproportionation constants close to 1.5 × 10(8). Evidence for a mixed valence state upon one electron reduction was also observed by spectroelectrochemistry in which a clear inter-valence charge-transfer (IVCT) band was observed in [4]- and [5]-complexes. The electronic structures of all target compounds were probed by DFT and TDDFT computational methods. DFT calculations indicate that reduction takes place at the diimine units, and that the observed coupling is a ligand-based phenomenon, rather than one that involves metal-based orbitals.

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“…We and others have frequently made use of Schiff base condensation reactions to create d 6 rhenium compounds with diimine-based bioconjugates formed by the reaction of pyridine-2-carboxaldehyde with amino acid esters [14, 15], amino acids [16], peptides [17] or amino alcohols [18]. Reactions of Re(CO) 3 + precursors and pyridine-2-carboxaldehyde with amino acid esters yielded discrete mononuclear complexes, Re(CO) 3 (pyca-Xxx-OR)Cl (pyca = pyridinecarbaldehyde imine, Xxx = amino acid), while amino acids or peptides yielded C 2 -symmetric dimers, [Re(CO) 3 (pyca-Xxx-O)] 2 or complex structures with extended hydrogen bonding networks.…”

Section: Introductionmentioning

confidence: 99%

The synthesis of biologically relevant conjugates of Re(CO)3 using pyridine-2-carboxyaldehyde

Costa

Chanawanno

Engle

et al. 2013

Journal of Organometallic Chemistry

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The new pyridine-2-carboxaldehyde adduct, Re(CO)3(NC6H5C(O)H)Cl 1, and previously reported complex Re(CO)3(NC6H5C(O)H)Br 2 react with aniline derivatives sulfanilamide or 4-aminofluorescein in methanol giving Schiff base conjugates Re(CO)3(pyca-R)X (pyca = pyridinecarbaldehyde imine, X = Cl, Br), 3–6. Pre-isolation of compounds 1 and 2 provides a convenient method for preparing conjugate complexes in addition to the known methods of ligand synthesis and one-pot reactions. All new compounds were completely characterized, and compound 1 and the sulfanilamide derivatives 3 and 4 were structurally elucidated by X-ray crystallography.

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Macrocycle Formation by Proton-Template-Induced Dimerization of Complexes with (Alkoxoimino)pyridine

Abstract: The existence of a strong hydrogen bond between two molecules of an (alkoxoimino)pyridinemanganese(I) complex induces their dimerization and the formation of a metallamacrocycle. The expected intramolecular attack of the alkoxo moiety is disfavored.

Cited by 9 publications

References 58 publications

The Synthesis of Dimeric Re^I–Phenylenediimine Conjugates: Spectroscopic and Electrochemical Studies

The Synthesis of Dimeric Re^I–Phenylenediimine Conjugates: Spectroscopic and Electrochemical Studies

Hydrazine-mediated strongly coupled Re(CO)₃dimers

The synthesis of biologically relevant conjugates of Re(CO)3 using pyridine-2-carboxyaldehyde

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Macrocycle Formation by Proton-Template-Induced Dimerization of Complexes with (Alkoxoimino)pyridine

Abstract: The existence of a strong hydrogen bond between two molecules of an (alkoxoimino)pyridinemanganese(I) complex induces their dimerization and the formation of a metallamacrocycle. The expected intramolecular attack of the alkoxo moiety is disfavored.

Cited by 9 publications

References 58 publications

The Synthesis of Dimeric ReI–Phenylenediimine Conjugates: Spectroscopic and Electrochemical Studies

The Synthesis of Dimeric ReI–Phenylenediimine Conjugates: Spectroscopic and Electrochemical Studies

Hydrazine-mediated strongly coupled Re(CO)3dimers

The synthesis of biologically relevant conjugates of Re(CO)3 using pyridine-2-carboxyaldehyde

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Product

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The Synthesis of Dimeric Re^I–Phenylenediimine Conjugates: Spectroscopic and Electrochemical Studies

The Synthesis of Dimeric Re^I–Phenylenediimine Conjugates: Spectroscopic and Electrochemical Studies

Hydrazine-mediated strongly coupled Re(CO)₃dimers