Control of Molecular Topology and Metal Nuclearity in Multimetallic Assemblies: Designer Metallosiloxanes Derived from Silanetriols

Abstract

Lipophilic N-bonded silanetriol RSi(OH)(3) (R=(2,6-iPr(2)C(6)H(3))N(SiMe(3))) can be utilized as an effective synthon for building a variety of multimetallic assemblies containing the Si-O-M motif. The type of metallosiloxane synthesized-its nuclearity and its molecular topology-can be readily modulated by the choice of the metal substrate, reaction stoichiometry, and reaction conditions. It is anticipated that the synthetic principles elaborated here will allow the design of many other multifunctional synthons.

High Catalytic Activity of Heterometallic (Fe₆Na₇and Fe₆Na₆) Cage Silsesquioxanes in Oxidations with Peroxides

“…Reactions of sodium siloxanolate with iron(III) chloride were carried out in various media (DMF, THF, DMSO, or 1,4-dioxane). All these solvents already proved to be proper solvating ligands for metallasilsesquioxane design [14][15][16][17][25][26][27][28].…”

“…Formation of complex II (26% yield, Figure 2) was observed when a ~1/1.4/0.33 ratio between interacting silane/NaOH/FeCl3 was used, while in the synthesis of I, ratio between reactants was ~1/1/0. 25 The most attractive feature of compounds I and II is the nature of their silsesquioxane ligands.…”

“…It is explained by the participation of specific siloxanolate [RSi(O)ONa] ligand in cage construction, giving rise to multiple metallasiloxane architectures [17]. It is also noteworthy that several reports have discussed in detail the influence of reactants ratio and/or choice of solvent system on structural features of cage-like metallasilsesquioxanes [14][15][16][17][25][26][27]. This tactics has been rarely used for Fe,Na-silsesquioxane design.…”

The Anhydride Route to Group 15/16 Ligands in Oligomeric and Polymeric Environments: From Metal Complexes to Supraionic Chemistry

“…For molecular chemists, however, there are two obvious routes to make use of anhydrides in synthesis. One is to generate models for naturally occurring anhydrides and investigate their chemistry as it has been recently described, for example, for metal silicates by Roesky et al [5] The second route involves the use of anhydride derivatives of inorganic acids (instead of carboxylic acids) and their transformations with metal salts. The fact that the latter approach can be used as a synthetic concept is illustrated in the following for novel Group 15/16 anions derived from thiophosphonic and selenophosphonic acid anhydrides (in this article the term anhydride is used for compounds derived from corresponding acids by formal loss of H 2 O, H 2 S and H 2 Se).…”

Binuclear Cage‐Like Copper(II) Silsesquioxane (“Cooling Tower”) – Its High Catalytic Activity in the Oxidation of Benzene and Alcohols

“…Cage-like metallasilsesquioxanes belong to the most attractive objects of contemporary organosilicon chemistry because of their extraordinary molecular architecture [1][2][3][4] and the potential of their subsequent practical use, for example, in obtaining metal-containing nanoparticles, [5] formation of hydroxy-or triorganosiloxy-bearing siloxane rings, [6,7] or creation of micro-or mesoporous inorganic materials. [8][9][10][11][12][13] Another direction of the usage of metallasilsesquioxanes, which currently looks quite promising, is their practical application in catalysis.…”