Polar Hydrophobicity

在有机化学和高分子化学项目的支持下，内布拉斯加州大学林肯分校化学系的斯蒂芬·迪马诺教授正在开发用于分子识别的氟化主机和客人的设计中的“极性疏水性”。通过合成和研究含有多个CF2(CHOH)取代的重氟碳水化合物类似物，DiMagno教授检验了这样一种假设，即由于电子极化引起的能量项的重要性降低，预先组织的位置和结合的客体比溶液中的同等结构“更硬”。极性疏水效应源于碳-氟键的特殊物理特性，它同时具有极强的极性和疏水性。由于C-F键的极性特性在结晶或有组织相中占主导地位，而疏水作用在溶液中更为重要，因此与天然底物相比，焓和熵因素都可能更有利于氟类似物的结合。因此，这些研究有望证明利用极性疏水性作为设计主体和客体的工具，并有助于对分子识别和氢键的一般理解。一种分子对另一种分子的特定识别和结合形成了无数化学和生化现象的基础。在有机化学和高分子化学项目的支持下，内布拉斯加州大学林肯分校化学系的斯蒂芬·迪马尼奥教授正在开发“极性疏水性”的概念，以设计用于分子识别的新类别的“宿主”和“客体”。迪马诺教授的研究集中在碳-氟键的特殊物理特征上，这种键同时具有极强的极性和高度的疏水性(憎水)。通过对糖的衍生物的研究，其中的极性和亲水性(亲水)基团被氟原子取代，DiMagno教授获得了关于极性和疏水相互作用在分子识别事件中的作用的信息，获得了关于用于一般分子识别研究的新的‘主机’和‘客人’的设计的实用知识，以及关于天然底物的生物识别的详细信息。

With the support of the Organic and Macromolecular Chemistry Program, Profesor Stephen DiMagno, of the Department of Chemistry at the University of Nebraska - Lincoln, is developing `polar hydrophobicity` in the design of fluorinated hosts and guests for molecular recognition. Through the synthesis and study of heavily fluorinated carbohydrate analogs incorporating multiple CF2 (for CHOH) substitutions, Professor DiMagno tests the hypothesis that preorganized sites and bound guests are `harder` than equivalent structures in solution due to the decreased importance of energetic terms arising from electron polarization. The polar hydrophobic effect results from the peculiar physical characteristics of the carbon-fluorine bond, which is at once both extremely polar and hydrophobic. Since the polar characteristics of the C-F bond dominate in crystalline or organized phases while hydrophobic effects are more important in solution, both enthalpic and entropic factors may be more favorable for binding fluorinated analogs than natural substrates. Thus, these studies are expected both to demonstrate the use of polar hydrophobicity as a tool for the design of hosts and guests and to contribute to the general understanding of molecular recognition and hydrogen bonding. The specific recognition and binding of one molecule by another forms the basis of a myriad of chemical and biochemical phenomena. With the support of the Organic and Macromolecular Chemistry Program, Professor Stephen DiMagno, of the Department of Chemistry at the University of Nebraska - Lincoln, is developing the concept of `polar hydrophobicity` in order to design new classes of `hosts` and `guests` for molecular recognition. Professor DiMagno's studies focus on the peculiar physical characteristics of the carbon-fluorine bond, which is at once both extremely polar and highly hydrophobic (water-hating). Through the study of sugar derivatives in which polar and hydrophilic (water-loving) groups are replaced by fluorine atoms, Professor DiMagno obtains information about the roles of polarity and hydrophobic interactions in molecular recognition events, gaining both practical knowledge about the design of new `hosts` and `guests` for general molecular recognition studies as well as detailed information about the biological recognition of natural substrates.