9702123 McGrath Research: This CAREER award presents the design, synthesis, and study of dendrimeric materials containing interior chiral moieties and the study of the fundamental relationships between chirality and conformational order in these materials. The primary goal of this research is to develop an understanding of the effect that chirality has on the conformational order of three-dimensional dendritic microstructures. The ultimate goal of this research is the development of new materials for asymmetric catalysis and chiral separations technologies. The initial phases of this research are a systematic study of the structure/property relationships of a large family of dendrimers of the same basic structure in an effort to elucidate the factors governing conformational asymmetry and chiral microenvironments in this class of synthetic macromolecules. The dendrimer systems proposed for study are based on enantiomerically pure 1,2-diol linkages and benzyl aryl or alkyl aryl ethers. These materials with asymmetrlc interior cavities and functional groups capable of attractive interactions (hydrogen bonding) should be able to selectively clathrate guests of a certain shape and functional group arrangement. Hence, host-guest interactions between the dendrimers and small molecules will be studied. These materials will then be tested for chiral discrimination in high performance liquid chromatography (HPLC) and micellar electrokinetic capillary chromatography (MECC). Selective encapsulation and guest binding will also be the basis for the development of these materials as multi-site reactors for asymmetric catalysis. Reaction rate acceleration will result from either (a) hydrophobic binding of reactants in the dendrimer interior or (b) reaction at transition metal catalytic centers anchored on the 1,2-diol linkages of the dendrimer. Teaching: Fewer women than men embark on c areers in the physical sciences. A woman's decision not to enter the sciences is rarely made at the graduate, undergraduate, or even high school level. Research has shown that very early social and cultural influences, rather than biological factors, steer girls away from science, with a sharp disparity in attitude towards science between boys and girls occurring between grades 4 and 8. It is proposed to address this problem by developing an outreach program to local elementary schools (grade 3 and 4) based upon providing encouragement of curiosity, hands on scientific experiences, and positive male and female role models with the aim of portraying science as an attractive activity/career opportunity for girls and young women to pursue. It is hoped that this heightened interest in science will help overcome the social, cultural, and curriculum factors which currently contribute to girls' declining attitudes towards science through the junior high years. %%% This research program will result in an understanding of the effect of chirality on the onformation of dendritic macromolecules and a new paradi gm for the design of chiral dendrimers which can provide asymmetric envir onments to encapsulated guest molecules. In addition, a new generation of materials with applications in chiral chromatographic separations and asymmetric catalysis will be prepared. ***
