Kinetic and Thermodynamic Stabilization of Metal Complexes by Introverted Coordination in a Calix[6]azacryptand

Alex Inthasot, Emilio Brunetti, Manuel Lejeune, Nicolas Menard, Thierry Prangé, Luca Fusaro, Gilles Bruylants, Olivia Reinaud, Michel Luhmer, Ivan Jabin, Benoit Colasson

Research output: Contribution to journalArticle

Abstract

The Huisgen thermal reaction between an organic azide and an acetylene was employed for the selective monofunctionalization of a X6-azacryptand ligand bearing a tren coordinating unit [X6 stands for calix[6]arene and tren for tris(2-aminoethyl)amine]. Supramolecular assistance, originating from the formation of a host–guest inclusion complex between the reactants, greatly accelerates the reaction while self-inhibition affords a remarkable selectivity. The new ligand possesses a single amino-leg appended at the large rim of the calixarene core and the corresponding Zn2+ complex was characterized both in solution and in the solid state. The coordination of Zn2+ not only involves the tren cap but also the introverted amino-leg, which locks the metal ion in the cavity. Compared with the parent ligand deprived of the amino-leg, the affinity of the new monofunctionalized X6tren ligand 6 for Zn2+ is found to have a 10-fold increase in DMSO, which is a very competitive solvent, and with an enhancement of at least three orders of magnitude in CDCl3/CD3OD (1:1, v/v). In strong contrast with the fast binding kinetics, decoordination of Zn2+ as well as transmetallation appeared to be very slow processes. The monofunctionalized X6tren ligand 6 fully protects the metal ion from the external medium thanks to the combination of a cavity and a closed coordination sphere, leading to greater thermodynamic and kinetic stabilities.
Original languageEnglish
Pages (from-to)4855-4862
Number of pages8
JournalChemistry: A European Journal
Volume22
Issue number14
Early online date16 Mar 2016
DOIs
Publication statusPublished - 24 Mar 2016

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Coordination Complexes
Metal complexes
Stabilization
Ligands
Thermodynamics
Kinetics
Metal ions
Bearings (structural)
Calixarenes
Acetylene
Azides
Dimethyl Sulfoxide
Amines
1,4,7,10,13,16,21,24-octaazabicyclo(8.8.8)hexacosane

Keywords

  • calixarenes, coordination chemistry, host–guest systems, selective functionalization, supramolecular chemistry

Cite this

Inthasot, Alex ; Brunetti, Emilio ; Lejeune, Manuel ; Menard, Nicolas ; Prangé, Thierry ; Fusaro, Luca ; Bruylants, Gilles ; Reinaud, Olivia ; Luhmer, Michel ; Jabin, Ivan ; Colasson, Benoit. / Kinetic and Thermodynamic Stabilization of Metal Complexes by Introverted Coordination in a Calix[6]azacryptand. In: Chemistry: A European Journal. 2016 ; Vol. 22, No. 14. pp. 4855-4862.
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abstract = "The Huisgen thermal reaction between an organic azide and an acetylene was employed for the selective monofunctionalization of a X6-azacryptand ligand bearing a tren coordinating unit [X6 stands for calix[6]arene and tren for tris(2-aminoethyl)amine]. Supramolecular assistance, originating from the formation of a host–guest inclusion complex between the reactants, greatly accelerates the reaction while self-inhibition affords a remarkable selectivity. The new ligand possesses a single amino-leg appended at the large rim of the calixarene core and the corresponding Zn2+ complex was characterized both in solution and in the solid state. The coordination of Zn2+ not only involves the tren cap but also the introverted amino-leg, which locks the metal ion in the cavity. Compared with the parent ligand deprived of the amino-leg, the affinity of the new monofunctionalized X6tren ligand 6 for Zn2+ is found to have a 10-fold increase in DMSO, which is a very competitive solvent, and with an enhancement of at least three orders of magnitude in CDCl3/CD3OD (1:1, v/v). In strong contrast with the fast binding kinetics, decoordination of Zn2+ as well as transmetallation appeared to be very slow processes. The monofunctionalized X6tren ligand 6 fully protects the metal ion from the external medium thanks to the combination of a cavity and a closed coordination sphere, leading to greater thermodynamic and kinetic stabilities.",
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Inthasot, A, Brunetti, E, Lejeune, M, Menard, N, Prangé, T, Fusaro, L, Bruylants, G, Reinaud, O, Luhmer, M, Jabin, I & Colasson, B 2016, 'Kinetic and Thermodynamic Stabilization of Metal Complexes by Introverted Coordination in a Calix[6]azacryptand', Chemistry: A European Journal, vol. 22, no. 14, pp. 4855-4862. https://doi.org/10.1002/chem.201505057

Kinetic and Thermodynamic Stabilization of Metal Complexes by Introverted Coordination in a Calix[6]azacryptand. / Inthasot, Alex; Brunetti, Emilio; Lejeune, Manuel; Menard, Nicolas; Prangé, Thierry; Fusaro, Luca; Bruylants, Gilles; Reinaud, Olivia; Luhmer, Michel; Jabin, Ivan; Colasson, Benoit.

In: Chemistry: A European Journal, Vol. 22, No. 14, 24.03.2016, p. 4855-4862.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Kinetic and Thermodynamic Stabilization of Metal Complexes by Introverted Coordination in a Calix[6]azacryptand

AU - Inthasot, Alex

AU - Brunetti, Emilio

AU - Lejeune, Manuel

AU - Menard, Nicolas

AU - Prangé, Thierry

AU - Fusaro, Luca

AU - Bruylants, Gilles

AU - Reinaud, Olivia

AU - Luhmer, Michel

AU - Jabin, Ivan

AU - Colasson, Benoit

PY - 2016/3/24

Y1 - 2016/3/24

N2 - The Huisgen thermal reaction between an organic azide and an acetylene was employed for the selective monofunctionalization of a X6-azacryptand ligand bearing a tren coordinating unit [X6 stands for calix[6]arene and tren for tris(2-aminoethyl)amine]. Supramolecular assistance, originating from the formation of a host–guest inclusion complex between the reactants, greatly accelerates the reaction while self-inhibition affords a remarkable selectivity. The new ligand possesses a single amino-leg appended at the large rim of the calixarene core and the corresponding Zn2+ complex was characterized both in solution and in the solid state. The coordination of Zn2+ not only involves the tren cap but also the introverted amino-leg, which locks the metal ion in the cavity. Compared with the parent ligand deprived of the amino-leg, the affinity of the new monofunctionalized X6tren ligand 6 for Zn2+ is found to have a 10-fold increase in DMSO, which is a very competitive solvent, and with an enhancement of at least three orders of magnitude in CDCl3/CD3OD (1:1, v/v). In strong contrast with the fast binding kinetics, decoordination of Zn2+ as well as transmetallation appeared to be very slow processes. The monofunctionalized X6tren ligand 6 fully protects the metal ion from the external medium thanks to the combination of a cavity and a closed coordination sphere, leading to greater thermodynamic and kinetic stabilities.

AB - The Huisgen thermal reaction between an organic azide and an acetylene was employed for the selective monofunctionalization of a X6-azacryptand ligand bearing a tren coordinating unit [X6 stands for calix[6]arene and tren for tris(2-aminoethyl)amine]. Supramolecular assistance, originating from the formation of a host–guest inclusion complex between the reactants, greatly accelerates the reaction while self-inhibition affords a remarkable selectivity. The new ligand possesses a single amino-leg appended at the large rim of the calixarene core and the corresponding Zn2+ complex was characterized both in solution and in the solid state. The coordination of Zn2+ not only involves the tren cap but also the introverted amino-leg, which locks the metal ion in the cavity. Compared with the parent ligand deprived of the amino-leg, the affinity of the new monofunctionalized X6tren ligand 6 for Zn2+ is found to have a 10-fold increase in DMSO, which is a very competitive solvent, and with an enhancement of at least three orders of magnitude in CDCl3/CD3OD (1:1, v/v). In strong contrast with the fast binding kinetics, decoordination of Zn2+ as well as transmetallation appeared to be very slow processes. The monofunctionalized X6tren ligand 6 fully protects the metal ion from the external medium thanks to the combination of a cavity and a closed coordination sphere, leading to greater thermodynamic and kinetic stabilities.

KW - calixarenes, coordination chemistry, host–guest systems, selective functionalization, supramolecular chemistry

U2 - 10.1002/chem.201505057

DO - 10.1002/chem.201505057

M3 - Article

VL - 22

SP - 4855

EP - 4862

JO - Chemistry: A European Journal

JF - Chemistry: A European Journal

SN - 0947-6539

IS - 14

ER -