The first lithium phenolate with a trinuclear structure and the tetranuclear product of 1 : 1 addition of lithium iodide; X-ray structures of [LiOAr]3 and [Li2(OAr)I]2[OAr = OC6H2(CH2NMe2)2-2,6-Me-4]

Schaaf, Paul A. van der; Hogerheide, M.P.; Grove, David M.; Spek, Anthony L.; Koten, Gerard van

doi:10.1039/c39920001703

Cited by 37 publications

(30 citation statements)

References 8 publications

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“…The molecular structure shown in Fig. 1 shows complex 1, which is a trimetallic lithium complex with the lithium centres bridged by phenolate oxygen atoms to form a Li 3) Å] are comparable to related trimetallic and bimetallic lithium complexes reported in the literature, 5,33,[37][38][39] but shorter than those (Li-O [1.938(3)-2.096(4) Å] and Li-N [2.158(3)-2.213(3) Å]) found for bridged phenoxide. 34 Crystals of complex 3 were also grown from toluene-hexane at −35 °C.…”

Section: Synthesis and Solid-state Structuressupporting

confidence: 67%

“…6 Furthermore, it has been established that lithium phenolates usually contain square Li 2 O 2 dimers or 'daisy-chain' Li 4 O 4 tetramers with μ 2bridging-phenolate interactions. In the literature, very few structurally characterized trimetallic lithium phenolate complexes have been reported: [LiOC 6 H 2 (CH 2 NMe 2 ) 2 -2,6-Me-4] 3 , 37 [LiOC 6 H 3 {2,6( i Pr) 2 }(THF)] 3 38 and [{Li(OC 6 H-3,5-t Bu 2 -2,6-Ph 2 )} 3 ]. 39 Following our recently reported work on zinc compounds of piperazinyl aminephenolate ligands, 18 which efficiently initiated the ring-opening polymerization of rac-lactide and ε-caprolactone in a controlled manner, we decided to study the chemistry of related Li complexes.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Ring-opening polymerization of ε-caprolactone by lithium piperazinyl-aminephenolate complexes: synthesis, characterization and kinetic studies

et al. 2012

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A series of lithium complexes were prepared from 2(N-piperazinyl-N′-methyl)-2-methylene-4-R′-6-Rphenols ([ONN] RR′ ) and characterized through elemental analysis, 1 H and 13 C{ 1 H} NMR spectroscopy, and X-ray crystallography. Treatment of the ligands with n-butyllithium afforded {Li [ONN] RR′ } 3 [R = Me, R′ = t Bu, (1); R = R′ = t Bu (2); R = R′ = t Am, (3), t Am = C(CH 3 ) 2 CH 2 CH 3 ], with trimetallic structures in the solid-state as shown by single-crystal X-ray diffraction. The reactivity of these complexes in the ring-opening polymerization of ε-caprolactone (ε-CL), as well as the influences of monomer concentration, monomer/Li molar ratio, polymerization temperature and time, was studied. Rates of polymerization were first order with respect to both monomer and lithium concentrations, and activation energies for the reactions were determined. MALDI-TOF MS analysis revealed that transesterification had occurred during the polymerization.

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Section: Synthesis and Solid-state Structuressupporting

confidence: 67%

Section: Introductionmentioning

confidence: 99%

Ring-opening polymerization of ε-caprolactone by lithium piperazinyl-aminephenolate complexes: synthesis, characterization and kinetic studies

et al. 2012

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“…To our knowledge the only related example is that of the lithium phenolate [Li-{OC 6 H 2 (CH 2 NMe 2 ) 2 -2,6-Me-4}] 3 , which forms a structure having a planar Li 3 O 3 6-membered ring. 23 Dimeric structures such as that of 5 are more common.…”

Section: Discussionmentioning

confidence: 99%

Structural Aspects of Lithium Arenethiolate Complexes with Intramolecular Coordinating Amine Donors

et al. 1996

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Reaction of aryllithium reagents LiR (R = C6H4((R)-CH(Me)NMe2)-2 (1a), C6H3(CH2NMe2)2-2,6 (1b), C6H4(CH2N(Me)CH2CH2OMe)-2 (1c)) with 1 equiv of sulfur (1/8 S8) results in the quantitative formation of the corresponding lithium arenethiolates [Li{SC6H4((R)-CH(Me)NMe2)-2}]6 (3), [Li{SC6H3(CH2NMe2)2-2,6}]6 (4), and [Li{SC6H4(CH2N(Me)CH2CH2OMe)-2}]2 (5). Alternatively, 3 can be prepared by reacting the corresponding arenethiol HSC6H4((R)-CH(Me)NMe2)-2 (2) with nBuLi. X-ray crystal structures of lithium arenethiolates 3 and 4, reported in abbreviated form, show them to have hexanuclear prismatic and hexanuclear planar structures, respectively, that are unprecedented in lithium thiolate chemistry. The lithium arenethiolate [Li{SC6H4(CH2N(Me)CH2CH2OMe)-2}]2 (5) is dimeric in the solid state and in solution, and crystals of 5 are monoclinic, space group P21/c, with a = 17.7963(9) Å, b = 8.1281(7) Å, c = 17.1340(10) Å, β = 108.288(5)°, Z = 4, and final R = 0.047 for 4051 reflections with F > 4σ(F). Hexameric 4 reacts with 1 equiv of lithium iodide and 2 equiv of tetrahydrofuran to form the dinuclear adduct [Li2(SAr)(I)(THF)2] (6). Crystals of 6 are monoclinic, space group P21/c, with a = 13.0346(10) Å, b = 11.523(3) Å, c = 16.127(3) Å, β = 94.682(10)°, Z = 4, and final R = 0.059 for 3190 reflections with F > 4σ(F).

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“…This planar geometry is similar to the lithium phenolate complex previously reported. 26 The O1−Li1 distance of 1.891(6) Å is slightly longer than the average Li−O distance (1.865(9) Å) found in the reported lithium phenolate complex.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…It is very interesting to note that the geometry around the methoxy oxygen atom is planar with an average angle of 119.5°, indicating the change in hybridization of the oxygen atom from sp 3 to sp 2 caused by the donation of lone pair of electrons from the filled oxygen p orbital to the empty boron p orbitals. This planar geometry is similar to the lithium phenolate complex previously reported . The O1–Li1 distance of 1.891(6) Å is slightly longer than the average Li–O distance (1.865(9) Å) found in the reported lithium phenolate complex.…”

Section: Resultsmentioning

confidence: 99%

Synthesis, Reactions, and Structures of Heterocycle-Tethered Boranes and Their Precursors

Subramaniyan

Mani

2017

Organometallics

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Heterocycle-tethered organoboranes generally dimerize by using the heteroatom present in them. When this does not take place, some interesting molecules or properties are bound to be observed. This is demonstrated in this work, as well. The lithium salt of 1,2-dimethylimidazole reacts with Et2B(OMe) or 9-BBN-OMe to give the air-stable intermolecular adduct of 2-(dialkylborylmethyl)-1-methylimidazole (alkyl = Et (1) and 9-BBN (2)) after treatment with BF3·OEt2. These two dimers exist in two stereoisomers: clockwise and counterclockwise, as shown by their X-ray structures. On the contrary, in the analogous reaction between the lithium salt of 1,3,5-trimethylpyrazole and Et2B(OMe) in the presence of BF3·OEt2, an air- and moisture-sensitive adduct, 1-(diethylborylmethyl)-3,5-dimethylpyrazole·BF2(OMe) (3), was isolated as a liquid in an excellent yield, instead of its dimer. Its structure is based on 1H, 19F, 11B, and HRMS methods and supported by anion binding studies. Consequently, the reactive neat liquid 3 decomposes in air to give the bicyclo[3.3.1]nonane-like neutral bicycle 4. Notably, a CH2Cl2 solution of 3 decomposes differently to give the OH-bridged cationic analogous bicycle 5. In addition, their precursors, [2-(diethylborylmethyl)-1-methylimidazole·LiOMe(1,2-dimethylimidazole)]2 6, [(1-(diethylborylmethyl)-3,5-dimethylpyrazole·LiOMe)2THF] 7, and [(1-(diethylborylmethyl)-3,5-dimethylpyrazole·LiOMe(DMAP)2] 8, were also isolated and structurally characterized. In the crystal lattices of structures of 4, 5, and 7, both enantiomers RR and SS are present.

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The first lithium phenolate with a trinuclear structure and the tetranuclear product of 1 : 1 addition of lithium iodide; X-ray structures of [LiOAr]3 and [Li2(OAr)I]2[OAr = OC6H2(CH2NMe2)2-2,6-Me-4]

Cited by 37 publications

References 8 publications

Ring-opening polymerization of ε-caprolactone by lithium piperazinyl-aminephenolate complexes: synthesis, characterization and kinetic studies

Ring-opening polymerization of ε-caprolactone by lithium piperazinyl-aminephenolate complexes: synthesis, characterization and kinetic studies

Structural Aspects of Lithium Arenethiolate Complexes with Intramolecular Coordinating Amine Donors

Synthesis, Reactions, and Structures of Heterocycle-Tethered Boranes and Their Precursors

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