6051-66-7Relevant articles and documents
A Charged Coordination Cage-Based Porous Salt
Gosselin, Aeri J.,Decker, Gerald E.,Antonio, Alexandra M.,Lorzing, Gregory R.,Yap, Glenn P. A.,Bloch, Eric D.
, p. 9594 - 9598 (2020)
Metal-organic frameworks and porous coordination cages have shown incredible promise as a result of their high tunability. However, syntheses pursuing precisely targeted mixed functionalities, such as multiple ligand types or mixed-metal compositions are often serendipitous, require postsynthetic modification strategies, or are based on complex ligand design. Herein, we present a new method for the controlled synthesis of mixed functionality metal-organic materials via the preparation of porous salts. More specifically, the combination of porous ionic molecules of opposite charge affords framework-like materials where the ratio between cationic cage and anionic cage is potentially tunable. The resulting doubly porous salt displays the spectroscopic signatures of the parent cages with increased gas uptake capacities as compared to starting materials. This approach will be widely applicable to all families of porous ions and represents a new and powerful method for the synthesis of porous solids with tailored functionalities.
PROCESS FOR PRODUCING AROMATIC POLYCARBOXYLIC ACID
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Page/Page column 13-14, (2011/04/18)
A process for producing an aromatic polycarboxylic acid in which all alkyl groups are converted into carboxyl groups in a high yield by decreasing a residual amount of an intermediate product is provided. The process comprises oxygen-oxidizing an aromatic compound having a plurality of alkyl groups (e.g., durene) in the presence of a catalyst containing a cyclic imino unit having an N—OR group (wherein R represents a hydrogen atom or a protecting group for a hydroxyl group) and a transition metal co-catalyst (e.g., a cobalt compound, a manganese compound, and a zirconium compound) under heating in a lower-temperature zone and a higher-temperature zone to produce an aromatic polycarboxylic acid in which a plurality of alkyl groups are oxidized into carboxyl groups. In an initial stage of the reaction, the reaction may be conducted in a first lower-temperature zone (a reaction temperature of 60 to 120° C. and a second lower-temperature zone (an intermediate temperature zone) (a reaction temperature of 100 to 140° C.); and then, in a latter stage of the reaction, the reaction may be conducted in a higher-temperature zone (a reaction temperature of 110 to 150° C.).
The complex synergy of water in the metal/bromide autoxidation of hydrocarbons caused by benzylic bromide formation
Partenheimer, Walt
, p. 297 - 306 (2007/10/03)
One of the most active and selective catalysts in homogeneous liquid phase oxidation using molecular oxygen (O2) is a mixture of cobalt, manganese and bromide salts in acetic acid. It has been used to produce hundreds of different carboxylic acids in high yield and purity including the commercial production of terephthalic acid from p-xylene. Water is normally a by-product in these reactions and it is shown here that its concentration is an important reaction variable. In anhydrous acetic acid, with reagents with sufficiently strong electron-withdrawing substitutents (toluene, 4-carboxytoluene, 4-chlorotoluene), all of the active bromide becomes inactive via benzylic bromide formation. The Co/Mn/ Br catalyst is therefore converted to a Co/Mn catalyst which is dubbed 'catalyst failure' because of its undesirable characteristics of lower activity, decreased selectivity especially towards over-oxidation and color formation. For 4-chlorotoluene, increasing the water concentration to 5 weight % initially decreases the rate of reaction but eventually is more active and selective because the oxidation and hydrolysis of the benzylic bromide allows for sufficient active catalytic bromide. It is shown that benzylic bromides do not 'promote' the reaction and that both oxidation and solvolysis of the benzylic bromide occurs during autoxidation. During polymethylbenzene oxidation, benzylic bromide formation occurs only with the most reactive methyl group. The complex factors during metal/bromide autoxidation -some favored by increased water concentration and others detrimental - are outlined.
