Lanthanoid complexes supported by retro-Claisen condensation products of β-triketonates

Galán, Laura Abad; Sobolev, Alexandre N.; Zysman‐Colman, Eli; Ogden, Mark I.; Massi, Massimiliano

doi:10.1039/c8dt03585g

Cited by 6 publications

(5 citation statements)

References 27 publications

(25 reference statements)

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“…The result is that there can be great difficulty attempting to synthesize these materials reproducibly even when carefully controlling for stoichiometry. Although the synthesis of these compounds seems simple, there are complications on account of the labile nature of the ligands, their acid–base reactivity, ability to tautomerize, and electrophilicity. ,− This results in the Hhfac ligand being able to undergo several side reactions including hydration to form a tetraol and retro-Claisen condensation to form trifluoroacetate. , …”

Section: Introductionmentioning

confidence: 99%

“…9,18−20 This results in the Hhfac ligand being able to undergo several side reactions including hydration to form a tetraol and retro-Claisen condensation to form trifluoroacetate. 13,21 Mechanochemical synthesis has the advantage of reducing the use of solvent and potentially reducing losses of soluble starting materials and products. Mechanochemistry has been used to synthesize various lanthanide complexes including some containing β-diketonates 22−28 as well as Ln-based metal−organic frameworks.…”

Section: ■ Introductionmentioning

confidence: 99%

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Mechanochemical Syntheses of Ln(hfac)₃(H₂O)_x (Ln = La-Sm, Tb): Isolation of 10-, 9-, and 8-Coordinate Ln(hfac)_n Complexes

et al. 2022

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Volatile lanthanide coordination complexes are critical to the generation of new optical and magnetic materials. One of the most common precursors for preparing volatile lanthanide complexes is the hydrate with the general formula Ln(hfac) 3 (H 2 O) x (x = 3 for La-Nd, x = 2 for Sm) (hfac = 1,1,1,5,5,5-hexafluoroacetylacetonato). We have investigated the synthesis of Ln(hfac) 3 (H 2 O) x using more environmentally sustainable mechanochemical approaches. Characterization of the products using Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, elemental analysis, and powder X-ray diffraction shows substantial differences in product distribution between methods. The mechanochemical synthesis of the hydrate complexes leads to a variety of coordination compounds including the expected hydrate product, the known retro-Claisen impurity, and hydrated protonated Hhfac ligand depending on the technique employed. Surprisingly, 10-coordinate complexes of the form Na 2 Ln(hfac) 5 •3H 2 O for Ln = La-Nd were also isolated from reactions using a mortar and pestle. The electrostatic bonding of lanthanide coordination complexes is a challenge for obtaining reproducible reactions and clean products. The reproducibility issues are most acute for the large, early lanthanides whereas for the mid to late lanthanides, reproducibility in terms of product distribution and yield is less of an issue because of their smaller size and greater charge to radius ratio. Ball milling increases reproducibility in terms of generating the desired Ln(hfac) 3 (H 2 O) x along with hydrated Hhfac (tetraol) and free Hhfac products. The results illustrate the dynamic behavior of lanthanide complexes in solution and the solid state as well as the structural diversity available to the early lanthanides.

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Section: Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Mechanochemical Syntheses of Ln(hfac)₃(H₂O)_x (Ln = La-Sm, Tb): Isolation of 10-, 9-, and 8-Coordinate Ln(hfac)_n Complexes

et al. 2022

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“…Ligands were synthesized by Claisen condensation according to the scheme previously described by the authors [20,21].…”

Section: Scheme 1 -Molecules Of Ligands Used In the Workmentioning

confidence: 99%

INVESTIGATION OF COORDINATION COMPOUNDS OF GADOLINIUM (III) WITH beta-DIKETONES

Berezhnytska¹,

Horbenko²,

Savchenko

et al. 2023

Preprint

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New coordination compounds of gadolinium with -diketones containing unsaturated and aliphatic or aromatic substituents in the -positions of the chelate ring have been synthesized. The performed quantum-chemical calculations of ligand molecules indicate the best acceptor properties of ligands with aromatic substituents. An analysis of the IR spectra and quantum chemical calculations of the metal complexes indicates the bidentate-chelate coordination of the ligand molecules and their arrangement in different planes, regardless of the nature and geometric structure of the substituent in the β-diketone molecule. The energies of the triplet levels of the ligands are calculated. The morphology and dispersion of the synthesized metal complexes have been studied.

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“…Ligands were synthesized by Claisen condensation according to the scheme previously described by the authors. 20,21 The synthesis of complexes was performed by the interaction of aqueous solutions of metal salts gadolinium nitrate (III) Gd(NO 3 ) 3 •5H 2 O (c.p) with an aqueous solution of sodium salt of the corresponding ligand at a molar ratio of reagents 1: 3 (pH 8-9) at room temperature.…”

Section: Scheme 1 Molecules Of Ligands Used In the Workmentioning

confidence: 99%

Investigation of Coordination Compounds of Gadolinium (III) With b-Diketones

Berezhnytska,

Horbenko,

Savchenko

et al. 2023

ChChT

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New coordination compounds of gadolinium with -diketones containing unsaturated and aliphatic or aromatic substituents in the -positions of the chelate ring have been synthesized. The performed quantum-chemical calculations of ligand molecules indicate the best acceptor properties of ligands with aromatic substituents. An analysis of the IR spectra and quantum chemical calculations of the metal complexes indicates the bidentate-chelate coordination of the ligand molecules and their arrangement in different planes, regardless of the nature and geometric structure of the substituent in the β-diketone molecule. The energies of the triplet levels of the ligands are calculated. The morphology and dispersion of the synthesized metal complexes have been studied.

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Lanthanoid complexes supported by retro-Claisen condensation products of β-triketonates

Abstract: Structures varying from polynuclear assemblies to coordination polymers are formed when β-triketonate ligands undergo retro-Claisen condensation reactions in the presence of lanthanoids.

Cited by 6 publications

References 27 publications

Mechanochemical Syntheses of Ln(hfac)₃(H₂O)_x (Ln = La-Sm, Tb): Isolation of 10-, 9-, and 8-Coordinate Ln(hfac)_n Complexes

Mechanochemical Syntheses of Ln(hfac)₃(H₂O)_x (Ln = La-Sm, Tb): Isolation of 10-, 9-, and 8-Coordinate Ln(hfac)_n Complexes

INVESTIGATION OF COORDINATION COMPOUNDS OF GADOLINIUM (III) WITH beta-DIKETONES

Investigation of Coordination Compounds of Gadolinium (III) With b-Diketones

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Lanthanoid complexes supported by retro-Claisen condensation products of β-triketonates

Abstract: Structures varying from polynuclear assemblies to coordination polymers are formed when β-triketonate ligands undergo retro-Claisen condensation reactions in the presence of lanthanoids.

Cited by 6 publications

References 27 publications

Mechanochemical Syntheses of Ln(hfac)3(H2O)x (Ln = La-Sm, Tb): Isolation of 10-, 9-, and 8-Coordinate Ln(hfac)n Complexes

Mechanochemical Syntheses of Ln(hfac)3(H2O)x (Ln = La-Sm, Tb): Isolation of 10-, 9-, and 8-Coordinate Ln(hfac)n Complexes

INVESTIGATION OF COORDINATION COMPOUNDS OF GADOLINIUM (III) WITH beta-DIKETONES

Investigation of Coordination Compounds of Gadolinium (III) With b-Diketones

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Mechanochemical Syntheses of Ln(hfac)₃(H₂O)_x (Ln = La-Sm, Tb): Isolation of 10-, 9-, and 8-Coordinate Ln(hfac)_n Complexes

Mechanochemical Syntheses of Ln(hfac)₃(H₂O)_x (Ln = La-Sm, Tb): Isolation of 10-, 9-, and 8-Coordinate Ln(hfac)_n Complexes