The crystalline structure of ureidopyrimidinone-based silane (UPY) has been determined. The local and long range order structuring of the bridged silsesquioxane (MUPY) resulting from the sol-gel hydrolysis-condensation of the former precursor has been investigated by MFTIR (Mid Fourier Transform InfraRed) combined with DFT (Density Functional Theory) and XRD (X-ray diffraction) studies. These studies showed that a long range structuring exists within the organic fragments with the transcription of the DDAA (Donor-Donor-Acceptor-Acceptor) H-bonding array from UPY to MUPY whereas a disordered siloxane network was revealed in the hybrid material.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/c2cp40250e | DOI Listing |
Dalton Trans
December 2024
Shandong University, Department of Chemistry and Chemical Engineering, Shanda South Road 27, 250100 Jinan, China.
The first metallasilsesquioxane bearing pyrazolylpyridine ligands, the Cu-based complex 1, adopts a cage-like structure with two zigzag-type copper tetramers sandwiched by two cyclic Si silsesquioxane ligands. The four 3-phenyl-5-(2-pyridyl)pyrazolate ligands in 1 exhibit dual (chelating and bridging) modes of ligation. Compound 1 is very active in the oxidation of alkanes and alcohols.
View Article and Find Full Text PDFChem Asian J
November 2024
Instituto de Química, UFRGS, CP 15003, CEP 91501-970, Porto Alegre, RS, Brazil.
In the present study, both short-range and long-range structural features of an ionic bridged silsesquioxane, specifically one containing the 1,4-diazoniabicyclo[2.2.2]octane chloride group (ISSQ), were elucidated.
View Article and Find Full Text PDFNanoscale
March 2024
Department of Organic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic.
Two spherical nanoparticulate materials were prepared by base-catalyzed sol-gel hydrolysis/self-condensation of the bis- alkaloid-phthalazine-based bridged bis(triethoxysilanes). For the purpose of comparing the catalytic properties, two compact materials were also prepared from the same precursors using a fluoride-catalyzed sol-gel process. All materials were characterized by SEM, TEM, solid-state Si NMR and C NMR, TGA, and FTIR.
View Article and Find Full Text PDFGels
April 2023
Institute of Inorganic Chemistry, Department of Chemistry and Physics, Technische Universität Bergakademie Freiberg (TUBAF), Leipziger Strasse 29, 09596 Freiberg, Saxony, Germany.
Condensation reactions of chlorosilanes (SiCl and CHSiCl) and bis(trimethylsilyl)ethers of rigid, quasi-linear diols (CH)SiO--OSi(CH) ( = 4,4'-biphenylene () and 2,6-naphthylene ()), with release of (CH)SiCl as a volatile byproduct, afforded novel hybrid materials that feature Si-O-C bridges. The precursors and were characterized using FTIR and multinuclear (H, C, Si) NMR spectroscopy as well as single-crystal X-ray diffraction analysis in case of . Pyridine-catalyzed and non-catalyzed transformations were performed in THF at room temperature and at 60 °C.
View Article and Find Full Text PDFJ Chromatogr A
February 2023
School of Pharmacy, Jiangsu University, Zhenjiang, 212013, China.
Periodic mesoporous organosilicas (PMO) hydrophilic microspheres were synthesized by co-condensation of sulfated polysaccharide from Lilum lancifolium Thunb. bridged silane (SLLTPBS) and polyhedral oligomeric silsesquioxane (POSS) as stationary phase (PMO(SLLTP-POSS)) for per aqueous liquid chromatography (PALC), which would overcome the disadvantages of using a large amount of acetonitrile on the hydrophilic interaction liquid chromatography (HILIC) columns. Average particle size of PMO (SLLTP-POSS) microspheres was 4.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!