Straightforward synthesis and structural characterization of the first alkoxy-zircono-silsesquioxanes — Potential models for zirconia–silica epoxidation catalysts

Viotti, Olle; Fischer, Andreas; Seisenbaeva, Gulaim A.; Kessler, Vadim G.

doi:10.1016/j.inoche.2010.03.044

Cited by 9 publications

(8 citation statements)

References 18 publications

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“…A single 29 Si{ 1 H}NMR absorption signal was observed in the region δ = −94.2 to −95.1 ppm in the 29 Si NMR spectra of all these derivatives, which falls within the expected range for Zr-OSiO 3 groups. 25 However, the appearance of only one signal in the 29 Si{ 1 H}] NMR spectra may be due to the formation of an equilibrium between tetra-and penta-coordinated states in solution at room temperature.…”

Section: Ir Spectrasupporting

confidence: 66%

“…Since benzene exhibits carcinogenic effects, therefore, due precautions were taken to handle it. The reaction of the zirconium alkoxides with silanols, even at low temperature, may also be carried out in toluene and the substituents can be produced simply by direct removal of toulene/isopropanol azeotrope, 29 however, without monitoring the progress of the reactions. The alkoxy zirconosiloxanes A and B solidify on ageing.…”

Section: Synthesis and Characterization Of Precursorsmentioning

confidence: 99%

“…H,13 C{ 1 H} and29 Si{ 1 H} NMR data (in δ ppm) of alkoxy zirconosiloxanes and its glycolato derivatives J = 6.0 Hz, CH 3 (OPr i )}; 1.26 {s, 27H, CH 3 (O t Bu)}; 4.24 (br, 3H, CH). 26.6 (CHMe 2 ); 32.1 (CMe 3 ); 70.9 (CHMe 2 ); 71.1 (CMe 3 ).…”

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confidence: 99%

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Molecular precursors for the preparation of homogenous zirconia–silica materials by hydrolytic sol–gel process in organic media. Crystal structures of [Zr{OSi(OtBu)3}4(H2O)2]·2H2O and [Ti(OtBu){OSi(OtBu)3}3]

et al. 2012

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[Zr(OPr(i))(4)·Pr(i)OH] reacts with [HOSi(O(t)Bu)(3)] in anhydrous benzene in 1:1 and 1:2 molar ratios to afford alkoxy zirconosiloxane precursors of the types [Zr(OPr(i))(3){OSi(O(t)Bu)(3)}] (A) and [Zr(OPr(i))(2){OSi(O(t)Bu)(3)}(2)] (B), respectively. Further reactions of A or B with glycols in 1:1 molar ratio afforded six chemically modified precursors of the types [Zr(OPr(i))(OGO){OSi(O(t)Bu)(3)}] (1A-3A) and [Zr(OGO){OSi(O(t)Bu)(3)}(2)] (1B-3B), respectively [where G = (-CH(2)-)(2) (1A, 1B); (-CH(2)-)(3) (2A, 2B) and (-CH(2)CH(2)CH(CH(3)-)} (3A, 3B)]. The precursors A and B are viscous liquids, which solidify on ageing whereas the other products are all solids, soluble in common organic solvents. These were characterized by elemental analyses, molecular weight measurements, FAB mass, FTIR, (1)H, (13)C and (29)Si-NMR studies. Cryoscopic molecular weight measurements of all the products, as well as the FAB mass studies of 3A and 3B, indicate their monomeric nature. However, FAB mass spectrum of the solidified B suggests that it exists in dimeric form. Single crystal structure analysis of [Zr{OSi(O(t)Bu)(3)}(4)(H(2)O)(2)]·2H(2)O (3b) (R(fac) = 11.9%) as well as that of corresponding better quality crystals of [Ti(O(t)Bu){OSi(O(t)Bu)(3)}(3)] (4) (R(fac) = 5.97%) indicate the presence of a M-O-Si bond. TG analyses of 3A, B, and 3B indicate the formation of zirconia-silica materials of the type ZrO(2)·SiO(2) from 3A and ZrO(2)·2SiO(2) from B or 3B at low decomposition temperatures (≤200 °C). The desired homogenous nano-sized zirconia-silica materials [ZrO(2)·nSiO(2)] have been obtained easily from the precursors A and B as well as from the glycol modified precursors 3A and 3B by hydrolytic sol-gel process in organic media without using any acid or base catalyst, and these were characterized by powder XRD patterns, SEM images, EDX analyses and IR spectroscopy.

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Section: Ir Spectrasupporting

confidence: 66%

Section: Synthesis and Characterization Of Precursorsmentioning

confidence: 99%

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Molecular precursors for the preparation of homogenous zirconia–silica materials by hydrolytic sol–gel process in organic media. Crystal structures of [Zr{OSi(OtBu)3}4(H2O)2]·2H2O and [Ti(OtBu){OSi(OtBu)3}3]

et al. 2012

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“…Poly(ethylene oxide) (PEO) chains were grafted onto octahydridosilsesquioxane (Q 8 M 8 H ) to obtain the PEO‐functionalized silsesquioxanes 10. The first representatives of alkoxy‐zircono‐silsesquioxane compounds have been prepared with quantitative yield by interaction of the corresponding zirconium alkoxides with the cycloalkyl‐substituted cage silsesquioxanes in hexane 11. POSSs have been added to different kinds of polymers to form the POSS containing O–I hybrids.…”

Section: Introductionmentioning

confidence: 99%

Curing octaepoxysilsesquioxane with different curing agents

Zhang

Liang

Fang

et al. 2012

J of Applied Polymer Sci

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Octaepoxysilsesquioxane (POSS‐Ep) was first synthesized by the hydrolysis and condensation of γ‐[(2,3)‐epoxypropoxy]propyltrimethoxysilicane (KH‐560) with the presence of ethanol and HCl at 55°C for 72 h. Then, it was cured with 4,4′‐diaminodiphenylsulfone (DDS) and methylnadic anhydride (MNA), respectively. The curing reactions between POSS‐Ep and DDS or MNA were investigated by FTIR. Thermal stability of the cured nanocomposites was studied by TGA. The micromophologies of the obtained hybrids were observed by SEM. FTIR results show that POSS‐Ep can be cured completely with DDS or MNA to obtain the final organic–inorganic (O–I) hybrids after the same experimental curing cycle: 120°C/2 h + 140°C/2 h + 160°C/2 h + 180°C/2 h + 200°C/2 h. TGA results show that POSS‐Ep/DDS hybrid displays better thermal stability than that of POSS‐Ep/MNA hybrid. Initial thermal degradation temperature (Tdi) of POSS‐Ep/DDS hybrid is 420°C, 195°C higher than that of POSS‐Ep/MNA (225°C). SEM images of the fracture surfaces of the hybrids suggest the cured POSS‐Ep possesses good mechanical properties. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

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“…Recently, many new POSS derivates containing various functional groups such as multi‐ N ‐methylol groups29 and epoxy rings30 have been synthesized. A number of metal‐containing POSS (Zr, Fe, Zn, and Al) were also reported 31–33. They have been introduced into several polymer matrixes to form organic–inorganic hybrids 34–36.…”

Section: Introductionmentioning

confidence: 99%

Methyl silsesquioxane/cyanate ester resin organic–inorganic hybrids with low dielectric constant

Zhang

Pei

Liang

et al. 2011

J of Applied Polymer Sci

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A kind of nonfunctional oligomeric silsesquioxane (SSQ), methyl silsesquioxane (Me-SSQ), was used to modify cyanate ester (CE) resin in this article. First, Me-SSQ was synthesized by the hydrolysis and condensation of methyltriethoxysilane. Then, a series of Me-SSQ/CE hybrids containing 0, 1, 5, 10, and 20 wt % of Me-SSQ were prepared. The effect of Me-SSQ content on the reactivity, mechanical, dielectric, thermal, and hot/wet properties of materials was investigated. Fourier transform infrared spectroscopy was used to study the reactivity of hybrid CE resin systems, indicating that the addition of Me-SSQ does not show significant effect on the conversion of CE. Mechanical and dielectric properties of the Me-SSQ/CE hybrid materials were also studied. Impact strength of the Me-SSQ/CE hybrids reaches its maximum value when Me-SSQ content is 5 wt %. However, the flexural strength reaches the maximum value when Me-SSQ content is 1 wt %. The Me-SSQ/CE hybrid containing 20 wt % of Me-SSQ shows a dielectric constant of 2.78, that is, much lower than the pure CE resin. At the same time, the dielectric loss of the Me-SSQ/CE hybrids was slightly increased (tan d < 0.006). Therefore, Me-SSQ/CE hybrid is a promising candidate for high-performance printed circuit board matrix materials.

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Straightforward synthesis and structural characterization of the first alkoxy-zircono-silsesquioxanes — Potential models for zirconia–silica epoxidation catalysts

Cited by 9 publications

References 18 publications

Molecular precursors for the preparation of homogenous zirconia–silica materials by hydrolytic sol–gel process in organic media. Crystal structures of [Zr{OSi(OtBu)3}4(H2O)2]·2H2O and [Ti(OtBu){OSi(OtBu)3}3]

Molecular precursors for the preparation of homogenous zirconia–silica materials by hydrolytic sol–gel process in organic media. Crystal structures of [Zr{OSi(OtBu)3}4(H2O)2]·2H2O and [Ti(OtBu){OSi(OtBu)3}3]

Curing octaepoxysilsesquioxane with different curing agents

Methyl silsesquioxane/cyanate ester resin organic–inorganic hybrids with low dielectric constant

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