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现代无机化学进展. 第 1 部分 超分子化学与晶体工程基础 (陈小明: 12 hrs) 第 2 部分 生物无机化学(黄锦汪教授 : 12 hrs) 第 3 部分 无机材料 (吴明娒教授: 12 hrs) 陈小明课件:存放在 suprachem_sysu@yahoo. com.cn 密码: super06 或者: http://ce.sysu.edu.cn/cxm/ Resources 课件 内容:课件、文献,格式 : pdf. PPT :分次提供. References. 麦松威 , 周公度: 《 高等无机结构化学 》 ,第二版,北大出版 , 2006.
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现代无机化学进展 第1部分 超分子化学与晶体工程基础(陈小明:12 hrs) 第2部分 生物无机化学(黄锦汪教授:12 hrs) 第3部分 无机材料 (吴明娒教授:12 hrs) 陈小明课件:存放在suprachem_sysu@yahoo.com.cn 密码:super06 或者:http://ce.sysu.edu.cn/cxm/Resources课件 内容:课件、文献,格式: pdf PPT:分次提供
References 麦松威, 周公度:《高等无机结构化学》,第二版,北大出版, 2006. J.W. Steed and J.L. Atwood, Supramolecular Chemistry, Wiley, 2000 Jean-Marie Lehn:《超分子化学——概念与展望》沈兴海等译,北京大学出版社,2002。 陈小明:配位聚合物组装化学,《无机合成与制备化学》,徐如人、庞文琴、霍启升主编,第11章,363-384页, 高等教育出版社,2009 无机化学中的重要领域: 无机材料,配位化学,超分子化学,生物无机化学 配合物晶体工程
现代无机化学进展 第1部分超分子化学与晶体工程基础 1.1 引言——历史、现在与未来 1.2 分子间的作用力 1.3 超分子化学基本概念 1.4晶体工程中的氢键 1.5配位聚合物晶体工程 Crystal Engineering ofCoordination Polymers 要点:基本概念,例子
1.1 Introduction What is Supramolecular Chemistry Chemistry beyond molecules (Lehn) 研究由非共价作用结合起来的分子有序聚集体的化学,分子间的键合(intermolecular bonding) Nobel Laureate C.J. Pedersen: Crown ether (冠醚) (1967) J.-M. Lehn (1969): Cryptand (多环穴状配体)、Spherand (穴状球形配体) D.J. Cram (early 1970): Cavitand (空穴配体) molecular recognition Landmarks: Nobel Prize in 1987 Journal: Supramolecular Chemistry in 1992 Monograph: Comprehensive Supramolecular Chemistry in 1994 (11 vols!) Edited by J.-M. Lehn, J.L. Atwood, J.E.D. Davies, D.D. MacNicol, F. Vögtle
Supramolecular Chemistry——Yesterday Early: ….Nobel laureatesand pioneers 1893 - Alfed Werner: coordination chemistry 1894 - Emil Fischer: lock and key 1939 -Linus Pauling:H-bonding in “The Nature of Chemical Bonds” 1940 - M.F. Bengen: urea channel inclusion compounds 1948 - H.M. Powell: the term ‘clathrate’(嵌合物)---enclosing of one component in the frameworkof another (Inclusion compound包合物) 1953 - Watson & Crick: structure of DNA 1961 - N.F. Curtis: first Schiff base 1967 -Charles Pederson:crown ethers 1969 -Jean-Marie Lehn: first cryptand 1973 -Donald Cram: spherand hosts 1978 - Jean-Marie Lehn: introduction of the term “supramolecular chemistry” defined as the ‘chemistry of molecular assemblies and of the intermolecular bonds’
Directeur : Jean-Marie LEHNProfessor at Collège de France Laboratoire de Chimie Supramoléculaire 8 allée Gaspard Monge BP 70028 F-67083 Strasbourg Cedex
Supramolecular Chemistry today Organic Supramolecular Chemistry:solution & solid state Crown ethers, spherands, cavitands, calixanes (杯芳烃), cyclodextrins (环糊精), molecular and ion recognition, supramolecular molecular devices, crystal engineering Inorganic Supramolecular Chemistry: solution &solid state Metal aggregates (聚集体), molecular tubes and networks, molecular devices, crystal engineering Biological Supramolecular Chemistry:solution DNA, interaction between metal complex or molecules with bio-macromolecules molecular/ionic transportation There is no strict borderline between them.
穴状球形配体 冠醚 穴醚 穴状配体 Host-guest interaction: recognition of molecules and ions Different in what aspects? shape and size 杯芳烃 球形配体
超分子催化:金属水解酶和SOD的模拟 超分子体系模拟+金属活性中心模拟 金属酶活性中心结构与功能 明显提高仿生催化活性(羧酸酯水解和SOD酶活性) 一种新的超分子催化剂的设计策略 环糊精+活性中心 • 毛宗万等,J. Am. Chem. Soc. 2006, 128, 4924 • 毛宗万等,Chem. Eur. J.2007,13, 2402
Supramolecular Chemistry today Interdisciplines: physists, theorists, inorganic and solid-state chemists, solution chemists, syntheticorganic chemists, biochemists, etc. Molecular recognition, Crystal engineering, Molecular architectures, Supramolecular devices, Host-guest chemistry, Coordination polymers Synthesis technology:Self-assembly, self-organization, templating A highly active, fast-growing field
Supramolecular Chemistry Tomorrow Unusual and unexpected molecular assemblies, topology Beauty of Chemistry and Molecules Materials: catalysis, separation (chirality and shape), molecular reactors, electronic, magnetic and optoelectronic materials Supramolecular devices: Molecular reactors, Nanomachines? Nanocomputers?
超分子化学的定义 “超分子化学就是分子间键合的化学,所研究的是由两个或者两个以上化学物种通过分子间键合而成实体的结构与功能” Supramolecular chemistry is the chemistry of the intermolecular bond, concerning the structure and functions of the entities formed by the association of two or more chemical species.(Jean-Marie Lehn) 分子间键:离子对(静电)、亲水与疏水、氢键、 p-p堆积、范德华等作用,甚至包括配位作用 分子化学: 分子内的共价、离子与金属-金属键(传统化学)
1.2. Intermolecular forces • Molecular Chemistry: covalent, ionic and metal-metal bonds ––Intramolecular bonding • Supramolecular Chemistry: charge groups, dipoles, H-bonds, hydrophobic (疏水)/ hydrophilic (亲水) interactions, p-p interactions, non-bonding electronic repulsion ––Intermolecular bonding
Molecular aggregates:held together by intermolecular forces (聚集体) Major intermolecular forces: non-directional: van der Waals interactions, directional: H-bonds, p-p interactions Strength: Intermolecular forces–––usuallyless than 10 kJ.mol–1 Distance: 0.3-0.5 nm (important,why?) Too short: intramolecular; too long: too weak kilo Joule per mol
1. Hydrogen bonding a) Basic Concept of H-bonding Energy: 2-120 kJ.mol–1 i) R, strength ii)q, strength directionality:hybridization of the donor/acceptor atoms ? iii) Energy: 10 ~ 100 kJ·mol–1 (vs: covalent >>100 kJ·mol–1) iv) Extreme cases: F···H···F (180o), ~0.22 nm, ~200 kJ·mol–1 O···H···O (180o), ~0.24 nm, <100 kJ·mol–1 C–H···p, <10 kJ·mol–1 (非经典)
氢键Hydrogen bonding AT and GC base pairs In solid and solution H-bonded carboxylic acid dimers and base pairing in DNA by H-bonding
氢键给体、受体原子的杂化形式( hybridization) sp2or sp3hybridizationorgin of geometry / direction! overlap of the sp2or sp3obitals with a proton 溶液中主要形式 轨道的重叠 ∝ 强度
氢键的种类 • OH···O (20-40 kJ/mol) • CH···O & OH···p (2-20 kJ/mol) • Hydrogen bonding donors/ [acceptors]: • C-H [A = different acceptors] (usually weak and very weak) • N-H [N] (usually strong) • O-H [O] (usually strong and very strong) • S-H [S] (usually weak and very weak) • X-H [X] (halogens) (usually weak and very weak except X = F) • A strong H-bond ≈ a very weak covalent bond (C-C is ~300 kJ/mol)
c) Significance of H-bonds in Supramol. Chem. H-bonding, the key for molecular recognition, is the most reliable, directional interaction in supramolecular construction, and its significance in crystal engineering can scarcely be underestimated. Role in molecular recognition:directionality, saturation Key points: Distance, geometry, and strength are the key parameters that must be considered when designing a target structure. The geometry of hydrogen bond donor-acceptor interactions is fairly well defined. It is accepted that linear hydrogen bonds are the strongest.
2. p-p stacking interaction a) Basic Concept of p-p stacking interaction Typical example:graphite Attraction between aromatic groups Energy: 1-50 kJ·mol–1 1 layer 2 layers C: sp2; fully conjugated system Adjacent layers are stacked in an off-set fashion offset face-to-face edge-to-face
Nature of p-p stacking interactions directional Simple model:Electronic (cloud) attraction Keys: distance (usually 0.33-0.37 nm) degree of the off-set (偏移)
Examples of p-p stacking interactions An infinite molecular zipper: offset face-to-face p-p stacking interaction Intercalation withp-p stacking interaction Role in molecular recognition:direction, saturation
3) van der Waals forces van der Waals forces are the ubiquitous (无所不在的) forces, including Dipole-dipole interactions, London forces (色散力), induced dipole (诱导偶极), which play a important role in Supramol. Chem. Dipole-dipole interactions (5-50 kJ.mol–1) Electronic static interaction van der Waals forces: < 5 kJ.mol-1
Characteristics of van der Waals forces • They are long range forces. They are effective over distances • greater than 10 nm down to "interatomic spacings" (~0.3 nm) • These forces may be repulsive or attractive • These forces not only bring molecules together, but also tend to • align them, though this orienting effect is usually weak • (generally < 5kJ/mol). • These forces arenon-directional. • 范德华力是一种弱的作用,作用距离在0.3-10nm之间,能量通常< 8kJ/mol; 可能是相互吸引、也可能是相互排斥作用;能影响分子的聚集和排列
van der Waals radii: non-convalent distances——a balance between repulsive and attractive interaction Related to the guest-host interaction, cage and porous (channel) sizes for accommodation of guest molecules or ions. Red and blue dots: the van der Waals forces area Role in molecular recognition: non-directional size and shape effect
Basis of Supramolecular Chemistry 2.1 Introduction Yesterday, Today and Tomorrow 2.2 Intermolecular Forces 2.3 Basic Concepts of Supramolecular Chemistry 2.4 Hydrogen-bonding in Crystal Engineering 2.5Crystal Engineering of Coordination Polymers
2.3 Basic Concepts of Supramolecular Chemistry • Molecular recognition • Self-assembly • Supramolecular synthons(合成子) • Crystal Engineering
1. Molecular Recognition:Complementarity Size, shape, chemical properties + Complementary Key and Lock(by Emil Fischer in 1894) Chemical Nature: H-bonding, p-p interactions, dipole-dipole interactions, van der Waals interactions, etc.
互补、匹配 Complementarity Size, shape, p-p stacking interaction An infinite molecular zipper: offset face-to-facep-p stacking interaction aryl-to-aryl distance? + Cu2+ ? Chen, X.-M.; et al., Chem. Eur. J. 2002, 8, 4811
Complementarity 4 H-bonds H-bonding recognition:directional ! donor-acceptor complementarity Important basis for molecular recognition 1 H-bonds ?
Complementarity H-bonding recognition:directional ! donor-acceptor complementarity Important basis for molecular recognition
Key points for molecular recognition Size, shape, p-p stacking interaction, H-bonding, van der Waals interactions, etc. Directional? Non-directional? Complementarity p-p stacking interaction, H-bonding van der Waals interactions, etc.
3. Self-assembly Molecular self-assembly: concerns the formation of covalent bonds as part of a special synthetic procedure. The assembly is subject to control the reaction stereochemistry and the conformation features of the intermediates Supramolecular self-assembly:concerns the recognition directed, reversible spontaneous association(可逆性自发缔合)of a limited number of components under the intermolecular control of relatively labile, noncovalent interactions, such as coordination interactions, hydrogen bonds and dipole-dipole interactions Key:Reversibility
Self-assembly Self-assembly by H-bonding Self-assembly by Coordination
3 Basic concepts: Supramolecularsynthons Synthon (合成子): first used by E.J. Corey in 1960s (Organic) “合成子”概念原先用于描述合成有机物的结构特点,被Desiraju推广来描述超分子基元。 “Supramolecular synthons are structural units within supramolecules which can be formed and/or assembled by known or conceivable synthetic operations involving intermolecular interactions.” (by Desiraju). 超分子合成子指的是超分子中的结构单元,这些结构单元可以通过已知或者可能的,包含超分子作用的合成操作而形成,并组装起来。
Hydrogen-bonded pairs: Examples will be shown in Organic crystal engineering 合成子:超分子组装的结构基元
Basis of Supramolecular Chemistry 1.1 Introduction Yesterday, Today and Tomorrow 1.2 Intermolecular Forces 1.3 Basic Concepts of Supramolecular Chemistry 1.4Hydrogen-bonding in Crystal Engineering 1.5Crystal Engineering of Coordination Polymers
phenol acetamide 1.4 Hydrogen-bonded molecular assemblies in solid state 1. Organic Donors and Acceptors for H-bonding good donors: bad donors: good acceptors: bad acceptors:
2. Basic properties of H-bonds (1) How many H-bonds can be formed? sp3 sp2 sp2 and sp3 hybridization overlap of a sp2/sp3 obitalwith a proton (2) Directional, reversible (association/dissociation), designable
3. Dimensionality and Examples The goal of crystal engineering is to recognize and design synthons that are robust enough, which ensures generality and predictability. Such structural predictability leads, in turn, to the anticipation of one-, two-, and three-dimensional patterns formed with intermolecular interactions. 晶体工程的目的是:认识和设计足够结实的合成子,以保证普适性和可预测性,从而通过分子间作用,形成所预期的1、2、3维结构 羧酸氢键对是最常用的超分子合成子。
(1)0-Dimensional (0-D) Example synthon
(2)1-Dimensional (1-D) Example synthon
(3)2-Dimensional (2-D) Example Honeycomb network observed for BTC): (a) H-bonding pattern (b) the hexagonal channels 蜂窝状网 disordered isooctane clathrate 正辛烷 space-filling model : van der Waals’ radii Herbstein, F. H.; et al.. J. Inclusion Phenom. 1987, 5, 211.
Interpenetration: from 2-D to 3-D Interpenetration Bend sheet These pictures show that the 'sheets' are NOT planar (in fact they contain an odd, yet interesting bend), and the 'cavity' is filled by another interlocked ring. The whole structure contains four separate 'sheets' that are all locked together to form what can be described as 'molecular fabric'.
Why Interpenetration? The solid become more stable. “Nature abhors a vacuum”! 自然憎恶真空 It is therefore difficult to generate porous solids or crystals, and appropriate templates or guest molecules are helpful in the formation of the channel structures. 故此,制备带有孔洞的固体、晶体并不容易。 合适的模板或者客体分子有利于通道结构的形成。
(4)3-Dimensional (3-D) Example Adamantane-1,3,5,7- tetracarboxylic acid (tetrahedral geometry ) The structural unit
(4)Other examples (1) 2-D network with N–H···O synthons Amide to carbonyl groups H Color codes: O NC
Stability: may be very good (up to 200oC) Solubility: may be very poor Practical application ? Possible——molecular or ionic exchange Practical application: Stability, Solubility, Pore size and Shape