Crystalline inclusions

In 1986, we have found that l,l,6,6-tetraphenylhexa-2,4-diyne-l,6-diol (1) includes various guest molecules in a stoichiometrical ratio and forms crystalline inclusion complexes.1 X-ray analysis of a 1 2 inclusion complex of 1 and acetone showed that the guest molecules are accommodated in inclusion crystalline cavity by the formation of hydrogen bond with the hydroxyl groups of l.2 It was also found that inclusion complexation with 1 occurs selectively, and a mixture of isomers can be separated by the selective inclusion process.3 This suggests that racemic guest compound can be separated into enantiomers by inclusion... 

Toda, F., Tanaka, K., Matsumoto, T., Nakai, T., Miyahara, I., and Hirotsu, K. (2000) A New Host 2,3,6,7,10,11-Hexahydroxytriphenylene Which Forms Chiral Inclusion Crystalline Lattice X-ray Structural Study of the Chiral Crystalline Lattice, J. Phys. Org. Chem., 13, 39-45. 

There are several ways of isolating molecules, in addition to dilution in appropriate solvents. For instance, extremely long PDA chains can be diluted in their monomer single crystal by exploiting the peculiar polymerization mechanism [91] of this class of polymers. In the case of CPs blended with non-conjugated macromolecules (polyethylene, polymethylmethacrylate, etc.) or inclusion crystalline compounds [92], the interaction between molecule and environment is usually strongly suppressed, but at the expense of the sample optical density, in a way that may easily challenge the common sensitivity of time-resolved techniques. 

Figure 7.6. Schematic drawing of the uano-scale iiiterphase and the models used to translate behavior of discrete matter consisting of molecules with segmental mobilitj reduced due to the presence of uano-scale solid inclusions. Crystalline inclusions surrounded by a number of long chain molecules can be modeled as a continuum, while amorphous inclusions with the extent of non-locality similar to polymers has to be considered discrete as well [170]...

Fig. 7. Schemes of crystalline cyclodextrin inclusion compounds (a) channel type (b) cage herringbone type (c) cage brick type (58).

In acidic solutions, equiUbtium is achieved more slowly. Polymerization of smaller species appears to occur sequentially a given polymer species first increases in size and then disappears, presumably because of its inclusion in higher order polymers. Depolymerization of siUcate species appears to be rapid, because crystalline Na2Si02 and Na2H2Si04 8H2O yield equivalent distributions of siUcate species in water upon dissolution. 

Flaws in the anodic oxide film are usually the primary source of electronic conduction. These flaws are either stmctural or chemical in nature. The stmctural flaws include thermal crystalline oxide, nitrides, carbides, inclusion of foreign phases, and oxide recrystaUi2ed by an appHed electric field. The roughness of the tantalum surface affects the electronic conduction and should be classified as a stmctural flaw (58) the correlation between electronic conduction and roughness, however, was not observed (59). Chemical impurities arise from metals alloyed with the tantalum, inclusions in the oxide of material from the formation electrolyte, and impurities on the surface of the tantalum substrate that are incorporated in the oxide during formation. 

As with the aliphatic polyamides, the heat deflection temperature (under 1.82 MPa load) of about 96°C is similar to the figure for the Tg. As a result there is little demand for unfilled polymer, and commercial polymers are normally filled. The inclusion of 30-50% glass fibre brings the heat deflection temperature under load into the range 217-231°C, which is very close to the crystalline melting point. This is in accord with the common observation that with many crystalline polymers the deflection temperature (1.82 MPa load) of unfilled material is close to the Tg and that of glass-filled material is close to the T. ... 

B. thurigiensis is a common Gram-positive, spore-forming soil bacterium that produces inclusion bodies, microcrystalline clusters of many different proteins. These crystalline proteins, called 5-endotoxins, are the ion channel toxins that are sold commercially for pest control. Most such endotoxins are protoxins, which are inactive until cleaved to smaller, active proteins by proteases in the gut of a susceptible insect. One such crystalline protoxin. 

Heat treatment at 400 °C of pure polymer specimens and composites containing 0.16 and 0.34 of calcite has shown [221] that the base polymer was sublimated without residue the specimen with Vf = 0.16 left a powder, and the specimen with Vf = 0.34 a brittle skeleton. Electron microscopy confirms that the latter consists of large crystalline inclusions interconnected by systems of small particles. 

Materials produced by crystalliferous bacilli which elicit a toxic response in susceptible insects may be separated into two types. The first type, the true toxins, include the crystalline protein inclusion body the parasporal body of Hannay (14)], a heat-stable, water-soluble exotoxin active against flies, a heat-stable, dialyzable water-soluble exotoxin, toxic to Lepidoptera on injection (23), and a heat-labile, water-soluble, filterable exotoxin, toxic toward larch sawfly larvae (Hymenoptera) which was reported by Smirnoff (31). 

A special case of polymorphic forms can be considered the clathrates, that is forms in which polymer molecules interact with solvents in the crystalline state and form inclusion compounds. 

For instance, one of the various crystalline forms of polyoxacyclobutane is a hydrate [62], Syndiotactic polymethylmethacrylate also forms nonstoichiometric inclusion compounds with a variety of solvents [63,64]. 

The following survey of the kinetics of dehydration of crystalline hydrates includes examples of the various types of behaviour commonly observed and unusual systems which merit inclusion in a general review. In this section (and also those which follow), the content is inevitably the product of selection since every relevant article cannot be individually cited. 

The mechanical behaviour of a two-phase composite system depends partly on the filler characteristics, such as the geometry of inclusions, their size, the size distribution, the orientation of inclusions, the filler volume-fraction, the relative positions between the inclusions, the physical state of the filler, etc. and partly on the matrix characteristics, which are related to the physico-chemical state of the matrix, the degree of its polymerization, the crystallinity, the degree of cross-linking, etc. 

To demonstrate the utilities of salt inclusion, we review the selected zeoUte-like transition-metal-containing open frameworks (TMCOFs) and then describe the structures of non-centrosymmetric solids (NCSs) and, finally, report crystalline solids containing a periodic array of transition metal nanostructures. In particular, we will address the issues concerning the role that molten salt has in... 

Organisms are more resistant to ethylene oxide treatment in a dried state, as are those protected from the gas by inclusion in crystalline or dried organic deposits. Thus, a further condition to be satisfied in ethylene oxide sterilization is attainment of a minimum level of moisture in the immediate product environment. This requires a sterilizer humidity of 30-70% and frequently a preconditioning of the load at relative humidities of greater than 50%. 

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