Siloxane Units Research Articles

Preparation of Polydimethylsiloxane Copolymers by the Azide–Alkyne Huisgen Cycloaddition Method

The copolymers containing alternating siloxane and urethane units in the chain as well as ester moieties were synthesized by the azide–alkyne cycloaddition without application of a solvent and copper salts as catalysts. The resulting copolymers were analyzed by NMR spectroscopy and gel permeation chromatography.

Oxygen-containing compounds in polydimethylsilanes and -carbosilanes

An analysis of fractions extracted from polydimethylsilanes, as well as distillates obtained during the synthesis of poly(oligo)carbosilanes was carried out. By the methods of gel permeation chromatography and chromatography-mass spectrometry, the range of molecular weights in extracts and distillates, the composition and structure of compounds, as well as the sequence of their retention times on the chromatographic column were determined. It was established that the compounds extracted from polydimethylsilanes are low molecular weight cycles containing methylsilane and/or methylsiloxane units. In distillates, compared with extracts, the number of low molecular weight compounds containing individual or mixed methylsilane, carbosilane and siloxane units increases.

Polymers from Plant Oils Linked by Siloxane Bonds for Programmed Depolymerization.

The increased production of plastics is leading to the accumulation of plastic waste and depletion of limited fossil fuel resources. In this context, we report a strategy to create polymers that can undergo controlled depolymerization by linking renewable feedstocks with siloxane bonds. α,ω-Diesters and α,ω-diols containing siloxane bonds were synthesized from an alkenoic ester derived from castor oil and then polymerized with varied monomers, including related biobased monomers. In addition, cyclic monomers derived from this alkenoic ester and hydrosiloxanes were prepared and cyclized to form a 26-membered macrolactone containing a siloxane unit. Sequential ring-opening polymerization of this macrolactone and lactide afforded an ABA triblock copolymer. This set of polymers containing siloxanes underwent programmed depolymerization into monomers in protic solvents or with hexamethyldisiloxane and an acid catalyst. Monomers afforded by the depolymerization of polyesters containing siloxane linkages were repolymerized to demonstrate circularity in select polymers. Evaluation of the environmental stability of these polymers toward enzymatic degradation showed that they undergo enzymatic hydrolysis by a fungal cutinase from Fusarium solani. Evaluation of soil microbial metabolism of monomers selectively labeled with 13C revealed differential metabolism of the main chain and side chain organic groups by soil microbes.

Effect of Molecular Architecture of Surface-Active Organosilicon Macromers on Their Colloidal Properties in Relation to Heterophasic Radical Polymerization of Styrene and Methyl Methacrylate

The effects of the molecular architecture of water-insoluble organosilicon polymerizable surfactant macromers (SAMs) on their colloidal-chemical characteristics and on their efficiency in heterophase radical polymerization of styrene and methyl methacrylate were studied. It was shown that despite considerable differences in the structure of three synthesized oligomers (linear α,ω-dipropylmethacrylatepolydimethylsiloxane with a number of repeated siloxane units n = 20—l-SAM; branched γ-methacryloxypropyl containing dimethylsiloxane oligomer—b-SAM; and “spherical” oligo-(γ-methacryloxypropyl)silsesquioxane—s-SAM), the colloidal-chemical characteristics (interfacial tension, layer thickness, adsorption, etc.) were rather similar. In particular, they all form “thick” multimolecular adsorption layers on the toluene–water interphase. All three SAMs were shown to act as effective colloidal stabilizers in heterophase radical polymerization of styrene and methyl methacrylate, which resulted in one-step preparation of large (0.5–1.5 µm) polymer particles with narrow particle size distribution. The obtained results are consistent with the published data on the use of water-insoluble polymerizable oligomers of various chemical structures on the heterophase radical polymerization. The use of these colloidal stabilizers may be considered as an effective way to obtain stable suspensions with large particles and narrow particle size distribution.

Synthesis of bent-shaped azobenzene main-chain polymers for photo-switching properties

This work presents the synthesis of the new bent-core polymers with siloxane units connected to the one side of azobenzene units. The structure of siloxane-based azobenzene bent-core polymers, 7a–c, was elucidated by spectral analysis (nuclear magnetic resonance and Fourier-transform infrared spectroscopy). The results of gel permeation chromatography suggested that all polymers (7a–c) showed polydisperse (polydispersity index >1). Besides, the extent of polymerization in the following order: 7a > 7b > 7c, where the degree of polymerization values were 7, 8 and 11, respectively. Polarizing optical microscopy revealed that the bent-core liquid crystal (BCLC) monomers, 6a and 6b, displayed the smectic A phase, whereas BCLC monomer 6c and all siloxane-based main-chain polymers (MCPs) (7a–c) were crystalline in nature. The result of ultraviolet-visible spectroscopy demonstrated that all MCPs (7a–c) exhibited strong photoisomerization behavior in solution. All polymers (7a–c) showed trans to cis isomerization in about 200 s, whereas the reverse process required much longer times ranging from 400 to 520 min in solution. The photo-switching study on azobenzene containing polymers stated that the effect of alkyl chain length and type of central core units on trans to cis isomerization were negligible. In contrast, both parameters influence the cis to trans process in which the photo-switching behavior of these materials may be primarily suitably exploited in the field of photo-induced phenomenon.

Synthesis and characterization of liquid crystal methyl methacrylic monomers

AbstractThree liquid crystalline monomers were systematically designed, synthesised and characterised. Methyl methacrylic unit was linked to the mesogenic compound, 4′-Undecycloxybiphenyl-4-yl 4-octyloxy-2-(pent-4-en-1-yloxy) benzoate, (Me), using disiloxane, ester and siloxane units respectively. In the first compound, 4′-(undecyloxy)-[1,1′-biphenyl]-4-yl 2-((5-(3-(4-(methacryloyloxy)butyl)-1,1,3,3-tetramethyldisiloxanyl)pentyl)oxy)-4-(octyloxy)benzoate, (M1), the methyl methacrylic unit was linked to the mesogen by disiloxane group, (Si–O–Si), while ester group, (COOC), was used in the second compound, 4′-(undecyloxy)-[1,1′-biphenyl]-4-yl 2-((5-(methacryloyloxy)pentyl)oxy)-4-(octyloxy)benzoate, (M2), and siloxane unit, (Si–O), in the third compound, 4′-(undecyloxy)-[1,1′-biphenyl]-4-yl 2-((5-((4-(methacryloyloxy)butyl)dimethylsilyl)pentyl)oxy)-4-(octyloxy)benzoate, (M3). The introduction of the methyl methacrylic unit caused the melting point of the compounds to reduce with Me melting at 53.3 °C, M1 at −8.1 °C and M2 at −12.5 °C. The three compounds showed characteristic nematic textures when observed under POM and when compared to the mesogenic compound (Me, 71.7 °C), there were remarkable reduction in the clearing points of the compounds, with M1 clearing at 18.6 °C, M2 at 68.8 °C and M3 at 10.3 °C. Finally, there was appreciable increment in the nematic phase range for the compounds when compared to the mesogen, Me, 18.4 °C. The range was 26.7 °C for M1, 81.3 °C for M2 and since there was no observable crystallization point for M3, the range was not determined.

Synthesis and characterization of UV curable biocompatible hydrophilic copolymers containing siloxane units

Tissues are highly three-dimensional structure complexes composed of different cell types and their interactions. One of the main challenges in tissue engineering is the inability to produce large, highly perfused scaffolds in which cells can grow at a high cell density and viability. Poly(dimethyl siloxane) (PDMS) is used as a flexible, biocompatible cell culture substrate with tunable mechanical properties. However, its fragility and hydrophobicity still pose a challenge. Here, we present a new strategy for the three-step one-pot synthesis of novel biocompatible hydrophilic copolymers containing siloxane units. In the first step, free radical copolymerization of acrylic acid (AA), butyl methacrylate (BMA), and 2-hydroxyethyl methacrylate (HEMA) was carried out in dioxane (DO) solution in the presence of 2,2′-azodiisobutyronitrile (AIBN). In the second step, the copolymers were modified with diepoxypropoxypropyl-terminated polydimethylsiloxane (DE-PDMS), and in the third step, the copolymers were additionally modified with glycidyl methacrylate (GMA). The modified copolymers were characterized by FTIR, NMR spectroscopy and elemental analysis. Films of modified copolymers were prepared by UV curing. SEM studies revealed microphase separated morphology with distribution of PDMS domains. The mechanical properties of the films depended on the amount of incorporated silicone modifier. The films were more hydrophilic than PDMS films. All novel copolymers showed high biocompatibility.

Synthesis and characterization of siloxane functionalized CO2-based polycarbonate

CO2-based polycarbonates are among the most promising eco-friendly polymers with excellent biodegradability and biocompatibility. However, the poor performance of conventional CO2-based polycarbonates such as poly(propylene carbonate) (PPC) and poly(cyclohexene oxide) (PCHC) limits their application. Herein, a series of siloxane functionalized CO2-based polycarbonates were obtained via terpolymerization of carbon dioxide (CO2), propylene oxide (PO), and [2-(3, 4-epoxycyclohexyl)-ethyl] trimethoxysilane (TMSO) using a SalenCoCl/PPNCl catalyst system. A systematic study of these polycarbonate's thermal, mechanical, and surface properties was conducted by tuning the ratio between TMSO and PO. The siloxane units offered polycarbonate with a higher surface energy, resulting in a water contact angle of 110° and a significant improvement in glass transition temperature (Tg) and decomposition temperature (Td). Additionally, the micro-crosslinked structure formed by the hydrolysis and condensation of methoxysilane groups provided to the polycarbonate's remarkable mechanical strength, with a high tensile strength of 46 MPa. As a result, a novel CO2-based polycarbonate derived from cost-efficient silane coupling agents and CO2 has shown promising results as an alternative to rigid plastics used in industry.

Metallacyclosilanes of Calcium, Yttrium, and Iron.

Utilizing a choice of α,ω-oligosilanylene diides, it is possible to synthesize a number of heterocyclosilanes with heteroelements of calcium, yttrium, and iron by metathesis reactions with respective metal halides CaI2, YCl3, and FeBr2. 29Si NMR spectroscopic analysis of the calcacyclosilanes suggests that these compounds retain a strong oligosilanylene dianion character, which is more pronounced than in the analogous magnesacyclosilanes. As the electronegativity of calcium lies between potassium and magnesium, silyl calcium reagents should be considered as building blocks with an attractive reactivity profile. Reaction of a 1,4-oligosilanylene diide with YCl3 gave the five-membered yttracyclosilane as an ate-complex with two chlorides still attached to the yttrium atom. Reaction of the obtained compound with two equivalents of NaCp led to another five-membered yttracyclosilane ate-complex with an yttracene fragment. When using a dianionic oligosilanylene ligand containing a siloxane unit, the siloxane oxygen acted as an additional coordination site for Ca and Y. When the same ligand was used to prepare a cyclic 1-ferra-4-oxatetrasilacyclohexane, an analogous transannular interaction between the iron and oxygen atoms is missing.

Preparation and properties of benzoxazine precursors containing siloxane units and their epoxy copolymers

Four siloxane benzoxazines containing different rigid segments were successfully synthesized and characterized herein, including a benzene ring, a biphenyl, a naphthalene ring, and a diphenyl sulfone group. Different rigid segments had different effects on polymer properties. The introduction of the naphthalene ring and sulfone group considerably reduced the curing temperature of benzoxazine. Although the benzoxazine with the naphthalene ring exhibited low heat resistance, all the four samples showed a high char yield at 800°C under nitrogen atmosphere. In addition, during copolymerization with AG-80 epoxy, the introduction of epoxy promoted the curing of the benzoxazines containing the naphthalene ring and sulfone group. The heat resistance of all copolymers was considerably improved, especially for the copolymer containing the naphthalene ring, whose 5% thermal weight loss temperature ( Td5) increased from 248°C to 321°C under nitrogen atmosphere. The copolymer containing the biphenyl structure had the highest glass transition temperature, reaching 259.1°C. Copolymerization with epoxy also considerably improved the tensile strength and elongation at break of the copolymers, which were much higher than those of traditional bisphenol A-aniline based benzoxazine (BA-a). Compared with the neat benzoxazine prepared using siloxane and bisphenol A, the developed copolymers also had better tensile properties, and the copolymer containing the sulfone group showed the greatest improvement (from 49 to 69 MPa, from 3.1% to 9.12%).

Inherent Flame-Retardant, Humid Environment Stable and Blue Luminescent Polyamide Elastomer Regulated by Siloxane Moiety.

The rapid development of the polymeric materials market has created an urgent demand for the thermoplastic polyamide elastomer (TPAE) owing to its greater functionality, and ability to be synthesized via a facile and industrial route. In this work, a series of novel silicone-containing polyamides (PA1212/Si12) were successfully synthesized from 1,12-dodecarboxylic acid (LA), 1,12-dodecarbondiamine (DMDA), and 1,3-bis (amino-propyl) tetramethyldisiloxane (BATS), via a one-pot melt polycondensation method in the absence of a catalyst. FTIR, 1H-NMR, GPC and inherent viscosity results cohesively prove that the polymerization of monomers was well conducted, and the chemical structure was in high accordance with the design. As expected, the Si12 unit-content of the copolymers regulate the properties of the series. As the feeding ratio of BATS in the diamines increases from 5 mol% to 40 mol%, the thermal transition temperatures, Tg and Tm, decline steadily before finally stabilizing at ~6 °C and 160 °C, respectively, indicating that the co-polyamides possess improved chain flexibility but restricted crystallization ability. The conspicuous evolution in crystalline morphology of the series was observed by XRD and AFM. The increased PA Si12 phase induces the crystallized PA 1212 phase to transit from a thermally-favorable large and rigid crystal structure (α phase) to a kinetically-favorable small and ductile crystal structure (γ phase). Reflected in their stress–strain behavior, PA1212/Si12 copolymers are successfully tailored from rigid plastic to ductile elastomer. The tensile strength mildly drops from above 40 MPa to ~30 MPa while the reversible elongation increases from ~50% to approximately 350%. Accordingly, the moderate surface tension differences in the monomers facilitate the efficient conduction of the co-polymerization process, and the distributed short siloxane unit in the backbone fulfills the copolymer with desirable elasticity. Interestingly, the novel silicone-containing polyamides also display Si12 unit-content dependent flame retardancy, humidity stability, and unconventional solid-state fluorescence properties. The elastomers exhibit a low bibulous rate and anti-fouling characteristics to dye droplets and mud contamination, pass the V–1 rating (UL 94) with a constantly declining PHRR value, and emit blue luminescence under a 365 nm light source. Herein, we propose a new facile strategy for developing a high-performance and multifunctional silicone-modified polyamide, which bears promising industrialization potential. In addition, this first reported silicone-containing thermoplastic polyamide elastomer, which is self-extinguishing, anti-fouling and blue-luminescent, will further broaden the application potential of thermoplastic polyamide elastomers.

Characterization and analysis of extended-wear silicone hydrogel contact lenses utilizing novel silicone macromers.

Contact lenses are one of the most successful biomaterials in history with a global market estimated to be worth over $17 billion in 2025. Silicone hydrogel contact lenses dominate the market and are complex biphasic biomaterials with several critical material properties needed for clinical use. Careful consideration of composition and chemistry is needed to identify formulations of lenses meeting all commercial standards with the potential for improved manufacturability, cost, and/or next generation use. Four silicone macromers were investigated in this work with varying symmetry of siloxane units and macromer structure, number of siloxane groups, branching, length, and concentration. Novel silicone hydrogel lenses were produced and evaluated for optical transmittance, elastic modulus, oxygen transmissibility, water content, and surface wettability. Several lenses met commercial standards and demonstrated an increase in oxygen permeability (Dk) and inverse relationship with elastic modulus and siloxane concentration, respectively. A hydrophobic/hydrophilic ratio below 1.4 was needed for a co‐continuous water phase. Substitution of methoxypropyl groups for butyl groups increased hydrophobic microdomains leading to decreased optical quality and mechanical properties. Generally, fluorine‐containing silicone macromers allowed for a wider range of successful compositions, and above a certain hydrophilic composition, the presence of trifluoropropyl groups resulted in improved solubility and optically clear lenses. Data also showed asymmetric siloxane macromers have potential to meet critical lens properties at lower overall siloxane content. New lens materials with wider composition ranges meeting all clinical lens properties is a significant challenge and may significantly expand the field.

Synthesis and characterization of novel poly(sulfone siloxane)s with good solubility and recyclability based on siloxane units

A controllable circulation between poly(sulfone siloxane)s (PSS) and sulfone-containing cyclosiloxane monomers (SCS) was acheived in the presence of KHSO4.

Mechanical properties and structures under the deformation of thiophene copolymers with cyclic siloxane units

The control of cross-linking of polythiophene with cyclic siloxane was achieved and provided to their mechanical properties and elastic recovery. The cross-links led to high recovery of crystallite orientation under stretching.

Transfer of gas chromatographic retention data among poly(siloxane) columns by quantitative structure-retention relationships based on molecular descriptors of both solutes and stationary phases

In the present study, computational molecular descriptors of 90 saturated esters and seven poly(siloxane) stationary phases with different polarity (SE-30, OV-7, DC-710, OV-25, XE-60, OV-225 and Silar-5CP) were combined into quantitative structure-retention relationship (QSRR) models aimed at predicting the Kováts retention indices (RIs) of the solutes. The molecular descriptors (174) of the stationary phases included in the models were computed using Dragon software from poly(siloxane) oligomers made of 20 siloxane units reflecting the nominal composition of the stationary phase, whereas 439 molecular descriptors were adopted to represent the esters. Different QSRR models were generated by means of Partial Least Squares (PLS) regression to assess the accuracy of this approach in predicting the RIs of unexplored solutes both in known and external stationary phases. After calibration of each PLS model, the descriptors were selected/discarded according to their relevance, evaluated by Covariance Selection (CovSel), and the PLS models were re-built, which resulted in a noticeable improvement of their predictive ability. Firstly, all the available data were equally divided into a training and a test set; the model built on the calibration set was used to predict the RIs of the validation observations. Successively, seven diverse PLS models were created following a “leave-one-column-out” fashion procedure, each one finalized to the estimation of the RIs of the 90 esters associated with a single stationary phase, whereas the calibration model was calculated on the remaining data. All the estimated models provided successful results on the external stationary phase, and predictive performance further increased after variable selection based on CovSel analysis. The final models provided a Root Mean Square Error in Cross Validation (RMSECV) in the range 12–20, a Root Mean Square Error in Prediction (RMSEP) in the range 11–26, and Mean Absolute Percentage Errors in Prediction (MAMEPs) in the range 0.7–1.5, revealing accurate cross-column prediction. Eventually, to test the robustness of the proposed approach, the 90 solutes were equally partitioned into a calibration and a test set and two further QSSR strategies were applied. The first PLS model was calibrated on all the seven stationary phases and the RIs of the 45 external solutes in the same seven columns were simultaneously predicted. The last QSRR approach followed a “leave-one-column-out” scheme and RI of 45 test solutes on an external stationary phase was predicted by a PLS model calibrated with the data of the 45 remaining solutes and the six left stationary phases. After selection of the significant molecular descriptors, PLS regression provided RMSECV values in the range 6–19, RMSEPs in the range 10–14, and MAPEPs in the range 0.9–2.4, revealing the suitability of the approach to deduce the RI of unknown solutes in uncharted stationary phases.

Facile construction of aggregation-induced emission molecular liquids via Piers-Rubinsztajn reaction for green fluorescent ink

Solvent-free luminescent molecular liquids (LMLs), which exhibit nonvolatile fluidic nature and active optoelectronic properties, were widely used. For further development, we introduced siloxane units into AIE molecules, designed and synthesized TPE derivatives with siloxane side chains via facile Piers-Rubinsztajn reaction. The obtained AIE molecular liquids exhibit unique photophysical properties. Compared with the obtained alkyl TPE-solids, siloxane TPE show liquid state, which proves that the siloxane units have stronger liquefaction effect than alkyl. Viscosity test shows that siloxane TPE-liquids has far more lower viscosity and better fluidity than the long-chain alkyl molecular liquids in previous research. All those properties are attributed to the weak interaction between flexible molecular chains of siloxane. Besides, fluorescence test shows temperature responsiveness of siloxane TPE-liquids. We developed this low-viscosity nonvolatile AIE molecular liquid as green fluorescent ink.

Study of the impurities in technical-grade 1,3,5-trimethyl-1,3,5-triphenylcyclotrisiloxane by gas chromatography-mass spectrometry

Polymerization of 1,3,5-trimethyl-1,3,5-triphenylcyclotrisiloxane is the main method for manufacturing methylphenylsiloxane rubbers, and copolymerization of octamethylcyclotetrasiloxane and 1,3,5-trimethyl-1,3,5-triphenylcyclotrisiloxane is the main method for production of high- and low-molecular weight dimethylmethylphenylsiloxane rubbers. The molecular weight, viscosity, and other properties of the obtained polymers depend on the purity of cyclosiloxanes. The technology of 1,3,5-trimethyl-1,3,5-triphenylcyclotrisiloxane production by thermocatalytic decomposition of methylphenylsiloxanes in the presence of lithium hydroxide or lithium silanolate, followed by vacuum rectification, makes it possible to obtain a product containing 1,3,5,7-tetramethyl-1,3,5,7-tetraphenylcyclotetrasiloxanes, tetraphenyldimethyldisiloxane as impurities and trace amounts of phenyl-containing siloxanes of cyclic and linear structure. The impurities of polycyclic and polyhedral structures have not been previously described. In this study, the method of gas chromatography-mass spectrometry is used to analyze compounds that can be present as impurities in technical-grade 1,3,5-trimethyl-1,3,5-triphenylcyclotrisiloxane. The use of the previously described regularities of the fragmentation of siloxanes of different structures made it possible to identify a number of siloxanes which are absent in the NIST 11 mass spectra library. It is shown that polycyclic and polyhedral compounds containing methylsilsesquioxane units have a short fragmentation path. They are characterized by ionization with the elimination of the methyl group and benzene in case of two phenyl groups in the molecule. The siloxane skeleton of such cations is rather stable, so they more readily lose another methyl group thus transforming into double-charged cations. The impact of electron ionization on the molecules with siloxane units containing different organic substituents at silicon leads to randomization of those substituents and rearrangement of the siloxane skeleton. Analysis of the results revealed that silanes, siloxanes of linear, cyclic, polycyclic and polyhedral structures are present in technical grade 1,3,5-trimethyl-1,3,5-triphenylcyclotrisiloxane.

Linear/Ladder-Like Polysiloxane Block Copolymers with Methyl-, Trifluoropropyl- and Phenyl- Siloxane Units for Surface Modification.

Multiblock copolymers containing linear polydimethylsiloxane or polymethyltrifluoropropylsiloxane and ladder-like polyphenylsiloxane were synthesized in a one-step pathway. The functional homopolymer blocks and final multiblock copolymers were characterized using solution and solid-state multinuclear 1H, 13C, 19F, and 29Si NMR spectroscopy. It was shown that the ladder-like block contains silanol units, which influence the adhesion properties of multiblock copolymers and morphology of their casted films. The adhesion to metals and mechanical properties of multiblock copolymers were tested. The SEM study of casted films of multiblock copolymers shows the variety of formed morphologies, including long-strip-like or globular.

Rare-Earth-Silyl ate-Complexes Opening a Door to Selective Manipulations.

The reactions of a number of rare-earth (RE) trichlorides and an oligosilanylene diide containing a siloxane unit in the backbone in DME are described. The formed products of the type [(DME)4·K][(DME)·RE(Cl)2{Si(SiMe3)2SiMe2}2O] (RE = Y, La, Ce, Pr, Sm, Tb, Dy, and Er) are disilylated dichloro metalate complexes and include the first examples of Si–La and Si–Pr compounds as well as the first structurally characterized example of a Si–Dy complex. A most intriguing aspect of the synthesis of these complexes is that they offer entry into a systematic study of the still largely unexplored field of silyl RE complexes by the possibility of ligand exchange reactions under preservation of the Si–RE interaction. This was demonstrated by the conversion of [(DME)4·K][(DME)·RE(Cl)2{Si(SiMe3)2SiMe2}2O] to [(DME)4·K][Cp2Y{Si(SiMe3)2SiMe2}2O].

Unusual Reactivity of Silicon Grease Towards Metal Alkoxides: Serendipity for Structural Chemistry

AbstractControlled synthesis of moisture sensitive metal alkoxides demands the use of silicon grease for the inert synthetic manipulation of starting materials using glass apparatus to avoid adventitious hydrolysis. Spontaneous reaction of the siloxane units (−OSi(Me3)2)n) with the synthesized alkoxides often leads to molecular metal alkoxides based siloxane frameworks. These spontaneous incorporation of siloxane units into homo‐ and heterometallic alkoxide building blocks lead to the new multinuclear homo‐ and heterometallic alkoxide‐siloxide compounds [Ce2(OtBu)4{Me2Si(OtBu)O}2(NO3)2] (1), [Zr{(OiPr)2{Me2SiO2}Sr{Zr2(OiPr)8}}2] (2) and [Sn2In2O2{Me2Si(OiPr)O}(OiPr)5]2 (3). Multifunctional coordination properties of these siloxane units enable the molecular approach to synthetically demanding polymetallic complexes for potential MOx‐SiOx nanocomposites fabrication.