184-26-9Relevant articles and documents
One-pot synthesis of ordered mesoporous zirconium oxophosphate with high thermostability and acidic properties
Miao, Zhichao,Xu, Leilei,Song, Huanling,Zhao, Huahua,Chou, Lingjun
, p. 1942 - 1954 (2013/07/26)
A series of mesoporous zirconium oxophosphate (M-ZrPO) with different P/Zr molar ratios (0-1.25) has been prepared via a facile one-pot evaporation-induced self-assembly (EISA) strategy. After removing the structure-directing agents, the M-ZrPO with large specific surface area (160 m2 g-1), big pore volume (0.26 cm3 g-1) and narrow pore size distribution (5.64 nm) has been obtained. Small-angle X-ray diffraction (SXRD) and transmission electron microscopy (TEM) results showed that these materials had ordered mesoporous structure. With the increase of P/Zr, the textural properties of M-ZrPO could be improved. Moreover, the ordered mesostructure could be maintained even when treated at 800°C, indicating the M-ZrPO had attractive thermal stability. NH3-TPD and pyridine-IR analyses showed the presence of abundant Broensted and Lewis acid sites in the material. The M-ZrPO has been used successfully as solid acid catalyst and showed excellent performance in the ketalization reaction.
Synthesis of phototrappable shape-shifting molecules for adaptive guest binding
Lippert, Alexander R.,Naganawa, Atsushi,Keleshian, Vasken L.,Bode, Jeffrey W.
supporting information; experimental part, p. 15790 - 15799 (2011/02/21)
We have designed and synthesized oligosubstituted bullvalenes 1 and 2 as adaptive molecules that can change their shapes in order to bind tightly to a suitable guest. By incorporation of a photolabile o-nitroveratryloxycarbonate (NVOC) group into bullvalenes 1 and 2, tightly binding species can be selectively isolated from a population of hundreds of interconverting structural isomers. Spontaneous strain-assisted Cope rearrangements allow these shape-shifting molecules to exist in a dynamic equilibrium of configurationally distinct valence isomers, as revealed by dynamic NMR and HPLC studies. When NVOC bullvalenes 1 and 2 were exposed to UV light, the cleavage of the NVOC group resulted in a mixture of static isomers of the corresponding bullvalone. Binding studies of NVOC bisporphyrin bullvalene 1 demonstrated that the dynamic isomeric equilibrium shifted in the presence of C60, favoring configurations with more favorable binding affinities. Irradiation of a mixture of 1 and C60 with UV light and isolation of the major static isomer yielded an isomer of bisporphyrin bullvalone with a binding affinity for C 60 that was ～2 times larger than that of the nonadapted isomer bisporphyrin bullvalone 41.
A simple and practical synthetic protocol for acetalisation, thioacetalisation and transthioacetalisation of carbonyl compounds under solvent-free conditions
Khan, Abu T.,Mondal, Ejabul,Ghosh, Subrata,Islam, Samimul
, p. 2002 - 2009 (2007/10/03)
A wide variety of carbonyl compounds can be converted smoothly to the corresponding acetals on treatment with alcohols or diols and triethyl orthoformate in the presence of a catalytic amount of (bromodimethyl)sulfonium bromide at room temperature. Similarly, various carbonyl compounds can be transformed into the corresponding dithioacetals on reaction with thiol or dithiols at room temperature by employing the same catalyst without any solvent. Moreover, O,O-acetals can also be converted into the corresponding dithioacetals under identical conditions. Some of the major advantages are mild reaction conditions, a high degree of efficiency, compatibilty with other protecting groups and the lack of solvents, particularly for thioacetalisation. In addition, no brominations occur at the double bond or α to the keto position or even in the aromatic ring under these experimental conditions. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
