超分子化学
孙俊奇
第一章
超分子化学导论
Chemistry in our life
■ Health ■ Energy/water/food ■ Population control ■ Information Technology ■ Global environmental stability ■ National security ■ Reinventing the supply chain ■ Understanding the living, material, and information-based worlds.
Supramolecular Chemistry (超分子化学)
(1) Molecular chemistry, the chemistry of the covalent bond, is concerned with uncovering and mastering the rules that govern the structures, properties and transformations of molecular species. (2) Supramolecular chemistry may be defined as “chemistry beyond the molecule”, bearing on the organized entities of higher complexity that result from the association of two or more chemical species held together by intermolecular forces. Its development requires the use of all resources of molecular chemistry combined with the designed manipulation of non-covalent interactions so as to form supramolecular entities, supermolecules possessing features as well delined as those of molecules themselves. One may say that supermolecules are to molecules and the intermolecular bond what molecules are to atoms and the covalent bond.
Chemistry
MOLECULAR
A B D SYNTHESIS polymolecular assembly C
SUPRAMOLECULAR
SELF-ASSEMBLY SELF-ORGANISATION
covalent bonds
RECOGNITION RECEPTOR
INTERACTION intermolecular bonds
SUPRAMOLECULE
TRANSFORMATION
MOLECULAR AND SUPRAMOLECULAR DEVICES
SUBSTRATE
TRANSLOCATION FUNCTIONAL COMPONENTS
Discovery of crown ether
0.4% Pederson C. J. 1967：the compound dissolved sparingly in methanol, but its solubility was enhanced significantly on addition of alkali metal salts. He eventually concluded: …the potassium ion had fallen into the hole at the center of the molecule.
C. J. Pedersen, J. Am. Chem. Soc. , 89, 2495, 7017 (1967).
Molecular Receptors—Design Principles
In order to achieve high recognition it is desirable that receptor and substrate be in contact over a large area. The simplest recognition: spherical recognition in crown ethers spherical substrates: positively charged metal cations (alkali, alkalineearth, lanthanide ions) or the negative halide anions. Ethers, esp. crown ethers, are good ligands for alkali metals
18-Crown-6
complex
2、cryptand （穴醚） and cryptate
1967年以来，J.M.Lehn等合成了一些双环的多元醚，即穴醚，穴醚 与碱金属配合物的稳定常数比类似冠醚配合物高二个数量级以上， 穴醚是天然离子载体和细胞膜的良好模拟物。由于冠醚，穴醚可以 作为主体（或受体），在主客体化学和超分子化学中已得到了广泛 的关注。
(a) Spherical recognition
1: Li+; 2: Na+; 3：K+
3与K+形成的 配合物
Donald J. Cram Host-guest chemistry (1974)
Complexes are composed of two or more molecules or ions held together in unique structural relationships by electrostatic forces other than those of full covalent bonds. The host component is defined as an organic molecule or ion whose binding sites converge in the complex. The guest component is defined as any molecule or ion whose binding sites diverge in the complex. We tried to interest graduate students in synthesizing chiral crown ethers from 1968 on, the efforts were unsuccessful. In 1970 we insisted that several postdoctoral co-workers enter the field. During 1973, we published five Communications on the subject. In 1974 with Jane M. Cram, we published a general article entitled “Host-Guest Chemistry”, which defined our approach to this research.
The Nobel Prize in Chemistry 1987
Donald J. Cram 1/3 of the prize USA 主客体化学 University of California Los Angeles, CA, USA b. 1919 d. 2001
Jean-Marie Lehn 1/3 of the prize France 发现穴醚配合物，超分 子化学概念 Université Louis Pasteur Strasbourg, France; Collège de France Paris, France b. 1939
Charles J. Pedersen 1/3 of the prize USA 发现冠醚配合物 Du Pont Wilmington, DE, USA b. 1904 (in Fusan, Korea) d. 1989
立项依据及拟解关键科学问题 超分子科学是21世纪新概念和高技术的一个重要源头
分子层次 分子以上层次
原子 原子
共价键
分子
合成
非共价键
分子聚集体 分子
自组装
超分子科学
纳米科学 结构生物学 分子电子学
超分子科学的研究对象是分子聚集体，分子聚集 体形成的本质是分子间相互作用，分子自组装是构 筑各种各样分子聚集体的有效手段。
History of Supramolecular Chemistry
The origin of supramolecular chemistry can be traced back to 1894 E. Fishcer in 1894: “Lock and Key ”, implying geometrical complementarity that lays the basis of molecular recognition. K.L. Wolf et al, Z. Phys. Chem., 1937, B36, 237 Molecular associations have been recognized and studied for a long time and the term “übermoleküle”, i.e. supermolecules, was introduced already in the mid-1930’s to describe entities of higher organization resulting from the association of coordinatively saturated species. The partners of a supramolecular species have been named molecular receptor（分子受体） and substrate （底物）, the substrate being usually the smaller component whose binding is being sought.
Supramolecular chemistry has been defined, conceptualized, and structured into a coherent system. Its roots extend into different subjects of chemistry and other physical science. 有机化学：分子构筑基元的合成
配位化学：分子受体化学的基础 物理化学：分子间相互作用的理论与实验研究 生物化学：生物的过程均从底物的结合与识别开始 高分子科学：材料科学与生物科学的桥梁
纳米科学： 生命科学： 物理学： Bottom-up 纳米构建 超分子生物学、结构生物学 介观物理
Life Lifescience science Molecular Molecular recognition recognition
E Enzyme function
Molecular Molecular self-organization self-organization
Biomembrane Liposome
2D Protein crystallization
+
Host/guest systems
Functional supramolecular systems
Micelles Monolayers
Surface functionalization Multilayers Liquid crystals
Function Function via via organization organization
Materials Materialsscience science
Order Order and and mobility mobility
Helmut Ringsdorf Angew Chem.Int.Ed. 1988, 23, 113.
超分子化学是关于分子间相互作 用和分子聚集体的化学
Self-assembly 自组装 Molecular recognition 分子识别 Supermolecules 超分子 Molecular assemblies 分子组装体 Supramolecular chirality 超分子手性 Molecular and supramolecular devices 分子和超分子器件 Supramolecular polymers 超分子聚合物
在超分子层次，分子组装的重要性 就如同分子化学中的合成
Self-assembly
Self-assembly may be defined as the process by which a supramolecular species forms spontaneously from its components.
关键词：自发，有序，非共价键
Molecular Recognition －－－－Recognition - Information - Complementarity
Molecular recognition has been defined as a process involving both binding and selection of substrate(s) by a given receptor molecule, as well as possibly a specific function. Mere binding is not recognition, although it is often taken as such. One may say that recognition is binding with a purpose, like receptors are ligands with a purpose. It implies a structurally well defined pattern of intermolecular interactions.
分子识别可定义为这样一个过程，对于一个给定的受体或者一个特殊功能， 底物选择性地与之键合。仅有键合并不是识别，因为识别和目的键合连在一 起。
超分子化学与生命科学
自然界的一切生命都是分子通过弱相互作用以非 常精密、准确、可控的方式自发自组装得到的。 因此要揭开生命起源的奥秘必须研究超分子自组 装。
1、超分子化学与生命科学