Zinc(II) Homogeneous and Heterogeneous Species and Their Application for the Ring‐Opening Polymerisation of <i>rac</i>‐Lactide

Jones, Matthew D.; Davidson, Matthew G.; Keir, Callum G.; Hughes, Laura M.; Mahon, Mary F.; Apperley, David C.

doi:10.1002/ejic.200801049

Cited by 96 publications

(22 citation statements)

References 45 publications

(40 reference statements)

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“…The ultimate goal was to isolate emissive SIMs. The salanH/salan − ligands have widely been used in transition and main group metal chemistries [66][67][68][69][70][71][72][73][74], but no Ln(III) complexes have been reported to date. The structural chemistry of the free salanH compound is exciting.…”

Section: Introductionmentioning

confidence: 99%

Mononuclear Lanthanide(III)-Salicylideneaniline Complexes: Synthetic, Structural, Spectroscopic, and Magnetic Studies

et al. 2018

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The reactions of hydrated lanthanide(III) [Ln(III)] nitrates and salicylideneaniline (salanH) have provided access to two families of mononuclear complexes depending on the reaction solvent used. In MeCN, the products are [Ln(NO3)3(salanH)2(H2O)]·MeCN, and, in MeOH, the products are [Ln(NO3)3(salanH)2(MeOH)]·(salanH). The complexes within each family are proven to be isomorphous. The structures of complexes [Ln(NO3)3(salanH)2(H2O)]·MeCN (Ln = Eu, 4·MeCN_Eu, Ln = Dy, 7·MeCN_Dy; Ln = Yb, 10·MeCN_Yb) and [Ln(NO3)3(salanH)2(MeOH)]·(salanH) (Ln = Tb, 17_Tb; Ln = Dy, 18_Dy) have been solved by single-crystal X-ray crystallography. In the five complexes, the LnIII center is bound to six oxygen atoms from the three bidentate chelating nitrato groups, two oxygen atoms from the two monodentate zwitterionic salanH ligands, and one oxygen atom from the coordinated H2O or MeOH group. The salanH ligands are mutually “cis” in 4·MeCN_Eu, 7·MeCN_Dy and 10·MeCN_Yb while they are “trans” in 17_Tb and 18_Dy. The lattice salanH molecule in 17_Tb and 18_Dy is also in its zwitterionic form with the acidic H atom being clearly located on the imine nitrogen atom. The coordination polyhedra defined by the nine oxygen donor atoms can be described as spherical tricapped trigonal prisms in 4·MeCN_Eu, 7·MeCN_Dy, and 10·MeCN_Yb and as spherical capped square antiprisms in 17_Tb and 18_Dy. Various intermolecular interactions build the crystal structures, which are completely different in the members of the two families. Solid-state IR data of the complexes are discussed in terms of their structural features. 1H NMR data for the diamagnetic Y(III) complexes provide strong evidence that the compounds decompose in DMSO by releasing the coordinated salanH ligands. The solid complexes emit green light upon excitation at 360 nm (room temperature) or 405 nm (room temperature). The emission is ligand-based. The solid Pr(III), Nd(III), Sm(III), Er(III), and Yb(III) complexes of both families exhibit LnIII-centered emission in the near-IR region of the electromagnetic spectrum, but there is probably no efficient salanH→LnIII energy transfer responsible for this emission. Detailed magnetic studies reveal that complexes 7·MeCN_Dy, 17_Tb and 18_Dy show field-induced slow magnetic relaxation while complex [Tb(NO3)3(salanH)2(H2O)]·MeCN (6·MeCN_Tb) does not display such properties. The values of the effective energy barrier for magnetization reversal are 13.1 cm−1 for 7·MeCN_Dy, 14.8 cm−1 for 17_Tb, and 31.0 cm−1 for 18_Dy. The enhanced/improved properties of 17_Tb and 18_Dy, compared to those of 6_Tb and 7_Dy, have been correlated with the different supramolecular structural features of the two families. The molecules [Ln(NO3)3(salanH)2(MeOH)] of complexes 17_Tb and 18_Dy are by far better isolated (allowing for better slow magnetic relaxation properties) than the molecules [Ln(NO3)3(salanH)2(H2O)] in 6·MeCN_Tb and 7·MeCN_Dy. The perspectives of the present initial studies in the Ln(III)/salanH chemistry are discussed.

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Section: Introductionmentioning

confidence: 99%

Mononuclear Lanthanide(III)-Salicylideneaniline Complexes: Synthetic, Structural, Spectroscopic, and Magnetic Studies

et al. 2018

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“…In 2009, Jones et al reported novel mono-and trinuclear zinc complexes of variously substituted phenoxyimine ligands [74]. All complexes exhibited good catalytic activity in the ROP of r-LA in melt conditions at 130 • C. While monozinc species afforded atactic PLAs with moderate control (M w /M n spanning from 1.42 to 1.50), broader polydispersities and moderately heterotactic polymers were achieved in the presence of the trinuclear analogues.…”

Section: Zincmentioning

confidence: 99%

Synthesis of Biodegradable Polymers: A Review on the Use of Schiff-Base Metal Complexes as Catalysts for the Ring Opening Polymerization (ROP) of Cyclic Esters

2020

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“…Zinc-based catalysts are the most promising for industrial applications due to their minimal toxicity. The successful application of zinc complexes for the ROP of LA has been extensively reviewed [31,[46][47][48][49][50]. Recently, a few zinc complexes bearing entiopure ligands were reported for use with LA polymerisation [51][52][53][54][55] and there were also some zinc complexes containing achiral ligands having afforded highly heterotactic PLA [56][57][58].…”

Section: Introductionmentioning

confidence: 99%

Synthesis, characterization and X-ray structures of enatiopure-diamine zinc(II) complexes as pre-catalysts for stereoselective production of poly(rac-lactide)

Nayab

Jeong

2013

Polyhedron

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Zinc(II) Homogeneous and Heterogeneous Species and Their Application for the Ring‐Opening Polymerisation of rac‐Lactide

Cited by 96 publications

References 45 publications

Mononuclear Lanthanide(III)-Salicylideneaniline Complexes: Synthetic, Structural, Spectroscopic, and Magnetic Studies

Mononuclear Lanthanide(III)-Salicylideneaniline Complexes: Synthetic, Structural, Spectroscopic, and Magnetic Studies

Synthesis of Biodegradable Polymers: A Review on the Use of Schiff-Base Metal Complexes as Catalysts for the Ring Opening Polymerization (ROP) of Cyclic Esters

Synthesis, characterization and X-ray structures of enatiopure-diamine zinc(II) complexes as pre-catalysts for stereoselective production of poly(rac-lactide)

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