Structurally different divalent metallasiloxanes [Mg{O(Ph2SiO)2}2]-μ-(LiPy)-μ-{(LiPy)3(OH)(Cl)}], [Cr{O(Ph2SiO)2}-μ-(LiPy2)2], and [{O(Ph2SiO)2}Co{O(Ph2SiO)3)}-μ-(LiPy2)2] from Ph2Si(OH)2/2BuLi and the metal dichlorides

Abrahams, Isaac; Lazell, Michael; Motevalli, Majid; Simon, Charlotte K.; Sullivan, Alice C.

doi:10.1007/bf02252164

Cited by 5 publications

(1 citation statement)

References 21 publications

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“…(1) In the first method the deprotonation of the disilanol Ph LH 2 with different bases MR (R = basic residue), e.g., n -BuLi, LiO t Bu, NaO t Bu, KO t Bu, and KH, is followed by treatment of the resulting Ph LM 2 with the transition metal halides. This led to the isolation of heterometallic complexes of the type [ Ph L 2 M T ]M 2 (e.g., M = Li + , M T = Co, Cr, , Cu; , M = Na + , M T = Cr; M = K + , M T = Cr). However, the suitability of basic compounds with M other than alkali metal ions for the deprotonation step is limited and often does not lead to the formation of the desired product.…”

Section: Resultsmentioning

confidence: 99%

Routes to Heterotrinuclear Metal Siloxide Complexes for Cooperative Activation of O₂

et al. 2020

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The assembly of heterometallic complexes capable of activating dioxygen is synthetically challenging. Here, we report two different approaches for the preparation of heterometallic superoxide complexes [PhL2CrIII-η1-O2][MX]2 (PhL = –OPh2SiOSiPh2O–, MX+ = [CoCl]+, [ZnBr]+, [ZnCl]+) starting from the CrII precursor complex [PhL2CrII]Li2(THF)4. The first strategy proceeds via the exchange of Li+ by [MX]+ through the addition of MX2 to [PhL2CrII]Li2(THF)4 before the reaction with dioxygen, whereas in the second approach a salt metathesis reaction is undertaken after O2 activation by adding MX2 to [PhL2CrIII-η1-O2]Li2(THF)4. The first strategy is not applicable in the case of redox-active metal ions, such as Fe2+ or Co2+, as it leads to the oxidation of the central chromium ion, as exemplified with the isolation of [PhL2CrIIICl][CoCl]2(THF)3. However, it provided access to the hetero-bimetallic complexes [PhL2CrIII-η1-O2][MX]2 ([MX]+ = [ZnBr]+, [ZnCl]+) with redox-inactive flanking metals incorporated. The second strategy can be applied not only for redox-inactive but also for redox-active metal ions and led to the formation of chromium(III) superoxide complexes [PhL2CrIII-η1-O2][MX]2 (MX+ = [ZnCl]+, [ZnBr]+, [CoCl]+). The results of stability and reactivity studies (employing TEMPO–H and phenols as substrates) as well as a comparison with the alkali metal series (M+ = Li+, Na+, K+) confirmed that although the stability is dependent on the Lewis acidity of the counterions M and the number of solvent molecules coordinated to those, the reactivity is strongly dependent on the accessibility of the superoxide moiety. Consequently, replacement of Li+ by XZn+ in the superoxides leads to more stable complexes, which at the same time behave more reactive toward O–H groups. Hence, the approaches presented here broaden the scope of accessible heterometallic O2 activating compounds and provide the basis for further tuning of the reactivity of [RL2CrIII-η1-O2]M2 complexes.

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Section: Resultsmentioning

confidence: 99%

Routes to Heterotrinuclear Metal Siloxide Complexes for Cooperative Activation of O₂

et al. 2020

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Linear Heterometallic Co₃Li₂ and Co₄Li₂ Siloxides: Precursors for the Plasma Synthesis of Adsorbent Materials

et al. 2013

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New linear heterometallic Co3Li2 and Co4Li2 arrays have been assembled with the use of disiloxanediolate and silsesquioxane ligands. Treatment of anhydrous CoCl2 with in situ‐prepared (Ph2SiOLi)2O afforded (thf)Co[Co{μ‐(Ph2SiO)2O}{(μ‐Cl)2Li(thf)2}]2 (5) as dark blue prisms in 73 % yield, while the analogous reaction of CoCl2 with in situ‐prepared Cy7Si7O9(OLi)3 (Cy = cyclohexyl) gave royal blue [Co2(μ‐Cy7Si7O12)(μ‐OSiMe3)(μ‐Cl){Li(thf)2}2]2 (6) in 68 % yield. Both of the new compounds have been structurally characterized by X‐ray crystallography. Plasma treatment of 5 was found to activate the surface by creating –C–O, –C=O, and –COO functionalities. An initial study revealed promising formaldehyde adsorption properties for the plasma‐treated material 5a.

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Chromium

Lay

Levina

2003

Comprehensive Coordination Chemistry II

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Structurally different divalent metallasiloxanes [Mg{O(Ph2SiO)2}2]-μ-(LiPy)-μ-{(LiPy)3(OH)(Cl)}], [Cr{O(Ph2SiO)2}-μ-(LiPy2)2], and [{O(Ph2SiO)2}Co{O(Ph2SiO)3)}-μ-(LiPy2)2] from Ph2Si(OH)2/2BuLi and the metal dichlorides

Cited by 5 publications

References 21 publications

Routes to Heterotrinuclear Metal Siloxide Complexes for Cooperative Activation of O₂

Routes to Heterotrinuclear Metal Siloxide Complexes for Cooperative Activation of O₂

Linear Heterometallic Co₃Li₂ and Co₄Li₂ Siloxides: Precursors for the Plasma Synthesis of Adsorbent Materials

Chromium

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Structurally different divalent metallasiloxanes [Mg{O(Ph2SiO)2}2]-μ-(LiPy)-μ-{(LiPy)3(OH)(Cl)}], [Cr{O(Ph2SiO)2}-μ-(LiPy2)2], and [{O(Ph2SiO)2}Co{O(Ph2SiO)3)}-μ-(LiPy2)2] from Ph2Si(OH)2/2BuLi and the metal dichlorides

Cited by 5 publications

References 21 publications

Routes to Heterotrinuclear Metal Siloxide Complexes for Cooperative Activation of O2

Routes to Heterotrinuclear Metal Siloxide Complexes for Cooperative Activation of O2

Linear Heterometallic Co3Li2 and Co4Li2 Siloxides: Precursors for the Plasma Synthesis of Adsorbent Materials

Chromium

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Product

Resources

About

Routes to Heterotrinuclear Metal Siloxide Complexes for Cooperative Activation of O₂

Routes to Heterotrinuclear Metal Siloxide Complexes for Cooperative Activation of O₂

Linear Heterometallic Co₃Li₂ and Co₄Li₂ Siloxides: Precursors for the Plasma Synthesis of Adsorbent Materials