3587-64-2Relevant articles and documents
-
Sparks,Nelson
, p. 671 (1936)
-
HYDROGEN-BONDING IN NON-CYCLIC VICINAL DIOLS AND THEIR MONO-METHYL ETHERS: AN FTIR STUDY
Singelenberg, F.A.J,Maas, J. H. Van Der
, p. 111 - 122 (1991)
Thirteen vicinal diols and their mono-alkyl ethers, dissolved in CCl4 and CS2, have been studied in the fundamental OH-stretching region.These systems are predominantly present in the intramolecular H-bonded form.The frequencies of the OH donor appears to be mainly determined by two effects: the character of the donor and its molecular surroundings.The frequency decreases on going over from primary to secondary and tertiary OH groups.The difference in the molecular surroundings is related to shielding of the H bond from the solvent and is expressed in a decrease ofthe frequency.For the diols evidence is found for a double, cyclic intramolecular H bond next to a single H bond in which one OH acts as a donor and another one as an acceptor.The proton of an acceptor OH is present in a preferential position and the corresponding OH frequency is increased with respect to the mono-hydroxy analogue.
Influence of Hydrogen Bond Donating Sites in UiO-66 Metal-Organic Framework for Highly Regioselective Methanolysis of Epoxides
Anbu, Nagaraj,Biswas, Shyam,Das, Aniruddha,Dhakshinamoorthy, Amarajothi,Sk, Mostakim
, (2020/02/18)
A Zr(IV)-based UiO-66 metal-organic framework (MOF) (named 1) was synthesized by employing 1-(aminomethyl)naphthalene-2-ol appended terephthalate linker and Zr(IV) salt via solvothermal method and subsequently characterized. Furthermore, the potential efficiency of activated (named 1′) form of as-synthesized MOF was investigated as an organocatalyst for the ring-opening of epoxide by methanol. The catalytic performance of 1 and 1′ was studied in the methanolysis of styrene oxide as a model substrate and the activity of 1′ was also examined with various alcohols. Under the optimized reaction conditions, the catalytic performance of 1′ reached 96 % conversion of styrene oxide to its corresponding product with 98 % regioselectivity. The reusability and stability of the catalyst were proved by recycling up to four runs in the methanolysis of styrene oxide. The Lewis acidity originating from metal nodes and hydrogen bond donating (HBD) sites in the linker is distributed homogeneously throughout the framework, thus playing crucial role in the activation of epoxide with easy accessibility.
Influence of functionalization of terephthalate linker on the catalytic activity of UiO-66 for epoxide ring opening
Blandez, Juan F.,Santiago-Portillo, Andrea,Navalón, Sergio,Giménez-Marqués, Mónica,álvaro, Mercedes,Horcajada, Patricia,García, Hermenegildo
, p. 332 - 339 (2016/12/09)
A series of five isostructural zirconium terephthalate UiO-66 metal organic frameworks bearing different functional groups on the terephthalate linker (UiO-66-X; X = H, NH2, NO2, Br, Cl,) have been successfully prepared and characterized. UiO-66-X materials were evaluated as heterogeneous catalysts for the epoxide ring opening of styrene oxide by methanol, observing an increase in the initial reaction rate from UiO-66-H to UiO-66-Br, over one order of magnitude. The reactivity order, however, does not follow a linear relationship between the Hammett constant value of the substituent and the initial reaction rate. UiO-66-Br exhibits a wide scope, its activity depending on the structure of epoxide and nucleophile. The absence of Zr leaching to the solution together with the preservation of the UiO-66-X crystallinity confirms the stability of the framework under the reaction conditions. Nevertheless, UiO-66 undergoes a progressive deactivation upon reuse that was attributed to a strong adsorption of the reaction product.
