Aluminium, gallium and indium complexes supported by a chiral phenolato-prolinolato dianionic ligand

Maudoux, Nicolas; Tan, Eric; Hu, Yuya; Roisnel, Thierry; Dorcet, Vincent; Carpentier, Jean‐François; Sarazin, Yann

doi:10.1515/mgmc-2016-0036

Cited by 9 publications

(3 citation statements)

References 74 publications

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“… Subsequent to our initial report, a variety of indium-based initiators have been reported in the literature for the polymerization of lactide (Figure ). − In this Account, we present an overview of our efforts to develop indium-based catalyst systems for the synthesis of novel and commercially relevant biodegradable polymers.…”

Section: Introductionmentioning

confidence: 99%

Indium Catalysts for Ring Opening Polymerization: Exploring the Importance of Catalyst Aggregation

Osten

Mehrkhodavandi

2017

Acc. Chem. Res.

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Inexorably, the environmental persistence and damage caused by polyolefins have become major drawbacks to their continued long-term use. Global shifts in thinking from fossil-fuel to renewable biobased resources have urged researchers to focus their attention on substituting fossil-fuel based polymers with renewable and biodegradable alternatives on an industrial scale. The recent development of biodegradable polyesters from ring opening polymerization (ROP) of bioderived cyclic ester monomers has emerged as a promising new avenue toward this goal. Ever increasing numbers of metal-based initiators have been reported in the literature for the controlled ROP of cyclic esters, in particular for the polymerization of lactide to produce poly(lactic acid) (PLA). PLA has several material weaknesses, which hinder its use as a replacement for commodity plastics. Despite many advances in developing highly active and controlled catalysts for lactide polymerization, no single catalyst system has emerged to replace industrially used catalysts and provide access to PLA materials with improved properties. We reported the first example of indium(III) for the ring opening polymerization of lactide. Since then, indium(III) has emerged as a useful Lewis acid in initiators for the controlled polymerization of lactide and other cyclic esters. In particular, we have developed a large family of chiral dinuclear indium complexes bearing tridentate diaminophenolate ligands and tetradentate salen and salan ligands. Complexes within our tridentate ligand family are highly active initiators for the moderately isoselective living and immortal polymerization of rac-lactide, as well as other cyclic esters. We have shown that subtle steric effects influence aggregation in these systems, with polymerization typically proceeding through a dinuclear propagating species. In addition, profound effects on polymerization activities have been observed for central tertiary versus secondary amine donors in these and other related systems. In contrast, our well-controlled and highly active chiral indium salen systems are more isoselective than the tridentate analogues and polymerize lactide via a mononuclear propagating species. Again, we have noticed that subtle steric and electronic changes to the ligand can influence both polymerization activity and stereoselectivity via aggregation phenomena. Recently, we have reported a promising new chiral indium catalyst supported by a tetradentate salan ligand. This catalyst is remarkably water and air stable and can be activated by linear and branched alcohols to provide controlled access to multiblock copolymers in air. This catalyst represents an important step forward toward generating new, commercially relevant catalysts for ROP of cyclic esters to produce novel biodegradable polymers, and highlights the unique value of indium-based catalysts in the field.

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Section: Introductionmentioning

confidence: 99%

Indium Catalysts for Ring Opening Polymerization: Exploring the Importance of Catalyst Aggregation

Osten

Mehrkhodavandi

2017

Acc. Chem. Res.

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“…In the present case, methylation was also observed in the 13 C SS-NMR spectra as broad signals with maxima positioned around −8.6 and −15.5 ppm chemical shift (Figure 7). The peak closest to 0 ppm can be assigned to mono-methylated silicon (O 3 -Si-CH 3 ) and the signal more up-field might derive from methylated gallium (O-Ga-CH 3 or O-Ga-(CH 3 ) 2 ) [94,95]. The formation of methoxy species or longer alkyl chains can be ruled out as they typically appear down-field at around 50 or 22 ppm [89,96,97].…”

Section: Determination Of Ligand Implementationmentioning

confidence: 99%

Synthesis of High Surface Area—Group 13—Metal Oxides via Atomic Layer Deposition on Mesoporous Silica

et al. 2022

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The atomic layer deposition of gallium and indium oxide was investigated on mesoporous silica powder and compared to the related aluminum oxide process. The respective oxide (GaOx, InOx) was deposited using sequential dosing of trimethylgallium or trimethylindium and water at 150 °C. In-situ thermogravimetry provided direct insight into the growth rates and deposition behavior. The highly amorphous and well-dispersed nature of the oxides was shown by XRD and STEM EDX-mappings. N2 sorption analysis revealed that both ALD processes resulted in high specific surface areas while maintaining the pore structure. The stoichiometry of GaOx and InOx was suggested by thermogravimetry and confirmed by XPS. FTIR and solid-state NMR were conducted to investigate the ligand deposition behavior and thermogravimetric data helped estimate the layer thicknesses. Finally, this study provides a deeper understanding of ALD on powder substrates and enables the precise synthesis of high surface area metal oxides for catalytic applications.

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“…Especially gallium concentrates the extraction of its complexes with methyl isobutyl ketone or ammonium pyrrolidin-dithiocarbamate [5]. Despite the fact that gallium forms numerous complex compounds with organic ligands, the ligands that are used in its determination are still relevant [10] [11].…”

Section: Introductionmentioning

confidence: 99%

Extraction-Atomic-Absorption Determination of Gallium (III) with 2-hydroxy-5-T-butylphenol-4’-methoxy-azobenzene

Pashajanov¹,

Bayramov²,

Abbasova³

et al. 2020

MSCE

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The complexation of gallium with 2-hydroxy-5-T-butylphenol-4'-methoxyazobenzene (HR) has been studied by atomic absorption and spectrophotometric methods. The optimal conditions for the formation and extraction of the complex were found. The maximum light absorption of the complex in n-butanol is in the range of 450-470 nm. The molar absorption coefficient is (3.3-4.2)⋅10 4. The stability constant of the gallium coordination compound in n-butanol is β l = 4.2⋅10 10. The developed technique allows to determine the gallium content within n × 10 −1-n × 10 −4 %. The selective and sensitive technique for the extraction-atomic absorption determination of gallium in soils has been developed.

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Aluminium, gallium and indium complexes supported by a chiral phenolato-prolinolato dianionic ligand

Cited by 9 publications

References 74 publications

Indium Catalysts for Ring Opening Polymerization: Exploring the Importance of Catalyst Aggregation

Indium Catalysts for Ring Opening Polymerization: Exploring the Importance of Catalyst Aggregation

Synthesis of High Surface Area—Group 13—Metal Oxides via Atomic Layer Deposition on Mesoporous Silica

Extraction-Atomic-Absorption Determination of Gallium (III) with 2-hydroxy-5-T-butylphenol-4’-methoxy-azobenzene

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