Unusual Stereochemical Opportunities in Extended Helical Conformations

点击翻译按钮获取中文摘要

This grant from the Organic Dynamics Program of the Chemistry Division and the Polymers Program of the Division of Materials Research supports the continuing work of Professor Green and Dr. Levon at the Polytechnic University. The results of this research will give new understanding and insight to the right or left hand helical nature of polymers. The factors that control the preferential formation of right- or left- handed helices will be explored. Since bio-polymers, such as peptides and DNA, can exist in right- or left- handed helices, this work is of particular interest. Drs. Green and Levon will provide new and important information in three areas, of which all are related to how the chirality of the monomers effect the helical chirality of the polymers. In the first area, the effect of a chiral center on the chiral helicity of isocyanate polymers will be studied. It has been found that a chiral center by virtue of deuterium substitution in R-1- deuteriohexylisocyanate had a profound effect on the helical chirality of the polyisocyanate. This observation will be studied further as well as the helical chirality of the polymer resulting from R-2-deuteriohexylisocyanate. In the second area, a study will be made of the relationship between helical twist of a side chain containing a biphenyl group in an N-carboxyanhydride monomer and helicity of the polyglutamate polymer. In the third area, the gelation of polyisocyanides as function of the stereochemistry of the monomer will be investigated.