CAREER: Structure/Property Relationships for Dendritic Macromolecules Containing Stereogenic Centers

9702123 McGrath研究：这一职业奖授予包含内部手性部分的树状聚合物材料的设计、合成和研究，以及这些材料中手性和构象顺序之间的基本关系的研究。这项研究的主要目的是了解手性对三维树枝状微结构构象顺序的影响。本研究的最终目标是开发用于不对称催化和手性分离技术的新材料。这项研究的初始阶段是对一大类具有相同基本结构的树状大分子的结构/性质关系进行系统的研究，以努力阐明控制这类合成大分子的构象不对称性和手性微环境的因素。建议研究的树枝状大分子系统是基于对映体纯的1，2-二醇键和苯基芳基或烷基芳基醚。这些材料具有不对称的内腔和能够产生吸引作用(氢键)的官能团，应该能够选择性地包裹特定形状和官能团排列的客体。因此，我们将研究树枝状大分子与小分子之间的主客体相互作用。然后，这些材料将在高效液相色谱(HPLC)和胶束电动毛细管色谱(MECC)中进行手性识别测试。选择性包覆和客体结合也将是这些材料发展成为不对称催化多中心反应器的基础。反应速度的加快是由(A)树枝状大分子内部反应物的疏水结合或(B)固定在树枝状大分子1，2-二醇键上的过渡金属催化中心的反应引起的。教学：从事自然科学研究的女性比男性少。在研究生、本科生甚至高中阶段，女性很少会做出不进入科学领域的决定。研究表明，早期的社会和文化影响，而不是生物因素，导致女孩远离科学，男孩和女孩对科学的态度在四年级和八年级之间存在巨大差异。有人提议通过在当地小学(三年级和四年级)开展一项外联计划来解决这个问题，该计划的基础是鼓励好奇心、亲身接触科学经验和积极的男性和女性榜样，目的是将科学描绘为女孩和年轻女性追求的一种有吸引力的活动/职业机会。希望这种对科学的兴趣的提高将有助于克服目前导致女孩在初中阶段对科学的态度下降的社会、文化和课程因素。这项研究计划将有助于理解手性对树枝状大分子构象的影响，并为手性树枝状大分子的设计提供新的途径，为手性树枝状大分子提供不对称环境提供包封的客体分子。此外，还将制备在手性色谱分离和不对称催化中应用的新一代材料。***

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. ***