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A meso compound or meso isomer is an optically inactive isomer in a set of stereoisomers, at least two of which are optically active. [1] [2] This means that despite containing two or more stereocenters, the molecule is not chiral. A meso compound is superposable on its mirror image (not to be confused with superimposable, as any two objects ...
For example, the battery performance of mesoporous electroactive materials is significantly different from that of their bulk structure. [ 5 ] A procedure for producing mesoporous materials (silica) was patented around 1970, [ 6 ] [ 7 ] [ 8 ] and methods based on the Stöber process from 1968 [ 9 ] were still in use in 2015. [ 10 ]
Mesoionic compounds are a subclass of betaines. [1] Examples are sydnones and sydnone imines (e.g. the stimulant mesocarb ), münchnones , [ 1 ] [ 2 ] and mesoionic carbenes . The formal positive charge is associated with the ring atoms and the formal negative charge is associated either with ring atoms or an exocyclic nitrogen or other atom. [ 3 ]
These include meso compounds, cis–trans isomers, E-Z isomers, and non-enantiomeric optical isomers. Diastereomers seldom have the same physical properties. In the example shown below, the meso form of tartaric acid forms a diastereomeric pair with both levo- and dextro-tartaric acids, which form an enantiomeric pair.
1,2,3,4-Butanetetracarboxylic acid is an organic compound with the formula HO 2 CCH 2 CH(CO 2 H)CH(CO 2 H)CH 2 CO 2 H. It is one of the simplest stable tetracarboxylic acids. The compound exists as two diastereomers, meso and the (R,R)/(S,S) pair. All are white solids. The compound is produced by oxidation of tetrahydrophthalic anhydride. [1]
For example, when this probability is 0.25 then the probability of finding: an isotactic triad is P m 2, or 0.0625; an heterotactic triad is 2P m (1–P m), or 0.375; a syndiotactic triad is (1–P m) 2, or 0.5625; with a total probability of 1. Similar relationships with diads exist for tetrads. [5]: 357
In chemistry and chemical physics, a mesophase or mesomorphic phase is a phase of matter intermediate between solid and liquid. Gelatin is a common example of a partially ordered structure in a mesophase. Further, biological structures such as the lipid bilayers of cell membranes are examples of mesophases. Mobile ions in mesophases are either ...
Examples of microporous materials include zeolites and metal-organic frameworks. Porous materials are classified into several kinds by their size. The recommendations of a panel convened by the International Union of Pure and Applied Chemistry (IUPAC) are: [1] Microporous materials have pore diameters of less than 2 nm.