Introduction chiral polymers

It has to be taken into account that these catalysts are not yet fully developed. Introduction of electron-withdrawing groups is suspected to increase Lewis acidity, which influences activity, and the optimum spacer length may enable formation of chiral polymers, but such variations are synthetically challenging. 

In summary, the examples given above demonstrate that immobilization of metal salts in a block copolymer micellar system followed by a reduction step is a suitable method to synthesize stable colloids with small particle sizes and narrow size distributions. Moreover, such systems are very interesting for catalytic applications because they offer the possibility of designing tailored catalysts for special demands and can be easily tuned by the choice and combination of different polymer block types and lengths, different types of the metal precursor and of the reduction method used. Additional introduction of further functionalities such as charges or chiral groups could make these catalyst systems even more versatile and effective. 

The introduction of sugars into polymeric molecules can bestow new properties, such as increased polarity, chirality, and biodegradability or biocompatibility. Sucrose-containing polymers can be of various types, either having the carbohydrate backbone within the polymer chain or having pendant sucrose residues serving as functional polar groups. 

Moreover, introduction of additional silane with chiral/achiral side groups to the 16-based copolymers permits fine control of the transition temperature (Tc) between -64 and +79°C. These results may open new methodologies in designing PM-transition polymers that may be promising in diverse screw-sense related applications, such as thermo-driven chiroptical switch and memory, a thermo-driven switching chiral separation column, and molecular recognition ability. 

A deeper understanding of the crystallization process is desirable and would be achieved if the helical chain conformation in the melt could be determined more exactly, if it were possible to know which helical hand the chains adopt in the melt, and compare it with that of the crystal that is formed. This issue is now addressed by considering (a) the evidence that the polymer melt is indeed organized to some extent - but this does not require a spinodal decomposition, and (b) the chiral polyolefins mentioned in the Introduction , for which the helical hand in the melt is known, and for which the helical hand in the crystal is also known. 

A large number of azobenzene-based amorphous and liquid crystalline polymers, particularly polyacrylates and polymethacrylates with chiral azobenzene pendants, have been prepared for the development of data storage and photonic devices [1-3,11-14]. For instance, the introduction of optically active mesogenic azobenzene residues into the side groups of the polymers produces chiral nematic and cholesteric phases, which are regulated by photoisomerization of the azobenzene units [10,14]. In most cases, however, the optical activity and chiroptical... 

Oligoureas are characterized by (i) hydrogen bonding groups inside the backbone (ii) chiral centers (iii) significant degree of conformational restriction and (iv) backbone NH groups available for the introduction of additional side chain functionalities. Such structures should provide new classes of folded polymers with novel conformational features... 

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