Guest Inclusion in Butadiyne- Bridged Macrocycles （ブタジイン架橋マクロサイクルのゲスト分子包摂） Tobe Lab. M1 Hiroshi Takeda 1

Contents Host–Guest Chemistry About Macrocycle Complexation of Butadiyne-Bridged Pyridinophane and Tropylium Cation STM & Guest Inclusion Ability My Work Summary 2

Contents Host–Guest Chemistry About Macrocycle Complexation of Butadiyne-Bridged Pyridinophane and Tropylium Cation STM & Guest Inclusion Ability My Work Summary 3

Host–Guest Chemistry Like the relation between “a key and a keyhole”, an enzyme reaction may show high selectivity. The molecules called host have spaces where they can selectively recognize a specific molecule. The molecules called guest are accepted in a host molecules. We create the substances which show new recog- nition ability, and study about their interaction. ＋ hostguest 4

Contents Host–Guest Chemistry About Macrocycle Complexation of Butadiyne-Bridged Pyridinophane and Tropylium Cation STM & Guest Inclusion Ability My Work Summary 5

About Macrocycle pyridinebutadiyne Butadiyne-bridged pyridinophane （ ） macrocycle 6

Mechanism of Complexation δ－δ－ δ－δ－ δ－δ－ δ－δ－ δ+ Ion Dipole Interaction The ion-dipole interaction refers to weak noncovalent bonds. It is due to interactions between ions and polar groups of molecules (or induced dipoles). Ion Dipole Interaction The ion-dipole interaction refers to weak noncovalent bonds. It is due to interactions between ions and polar groups of molecules (or induced dipoles). 7

Titration of Pyridinophan 8 1 R= 8 H H

Titration of Pyridinophan H 9 1 R=C 8 H 17 Addition of guest Shift 9 c hemical shift concentration K K is complex formation constant : 錯形成定数

Contents Host–Guest Chemistry About Macrocycle Complexation of Butadiyne-Bridged Pyridinophane and Tropylium Cation STM & Guest Inclusion Ability My Work Summary 10

Complexation of Butadiyne-Bridged Pyridinophane and Ｔ ropylium Cation in Ｓ olution R=C 8 H 17 To examine the binding ability of pyridinophanes 1 and 2, we choose tropylium ion as a guest ⇒ the cation size is slightly larger than the cavity of 1 but it is too small to fit the cavity of 2. tropylium ion

Complexation of Butadiyne-Bridged Pyridinophane and Tropylium Cation in Solution R=C 8 H 17 The nonlinear least-squares regression analysis gave K11(1:1) and K21(2:1) → For 1, K11 = 3×10 3 M -1 and K21 = 3×10 4 M -1 For 2, K11 = 1×10 2 M -1 and K21 = 4×10 2 M -1 The larger binding constants of 1 than those of 2 →The size of the cavity of 1 which fits better than that of 2. > K11(1:1)K21(2:1) 13 × × × ×10 2 K is complex formation constant : 錯形成定数

Contents Host–Guest Chemistry About Macrocycle Complexation of Butadiyne-Bridged Pyridinophane and Tropylium Cation STM & Guest Inclusion Ability My Work Summary 13

Until the former half of the 1980s, It was the dream for researchers to study a substance with an atomic level by using the atomic resolution microscope. BinnigRohrer A scanning tunneling microscope (STM) is an instrument for imaging surfaces at the atomic level. Its development in 1981 ear- ned its inventors, Gerd Binnig and Heinrich Rohrer (at IBM Zürich), the Nobel Prize in Physics in Invention of ＳＴＭ (Scanning Tunneling Microscopy) Scanning Tunneling Microscopy(STM) 14

Scanning Tunneling Microscopy (STM) Tunneling current electron Tunneling current Tip Sample 15

Scanning Tunneling Microscope (STM) Small change d (distance) J i (tunneling current) Large change J i = Aexp(-Bd) J i : tunneling current A, B : constant d : distance Tip Sample 16

Self-Assembly of Butadiyne-Bridged Pyridinophane 17 R = COOC 8 H 17 1

Guest Inclusion Ability of Butadiyne- Bridged Pyridinophane on Solid Surfaces The brighter spots within the cavity of 1 are trapped tropylium cations. An empty macrocycle 1 ＋ 18 R = COOC 8 H 17 1

Guest Inclusion Ability of Butadiyne- Bridged Pyridinophane on Solid Surfaces ・ Squares filled with a bright spot are 1+ tropylium cation complex ・ Darker square features are 3 ・ They appear randomly in the domains ＋ 19 R = COOC 8 H 17 13

Guest Inclusion Ability of Butadiyne- Bridged Pyridinophane on Solid Surfaces ・ Squares filled with a bright spot are 1+ tropylium cation complex ・ Darker square features are 3 ・ They appear randomly in the domains 20 R = COOC 8 H Only 1 formed the complex with tropylium cation !

Contents Host–Guest Chemistry About Macrocycle Complexation of Butadiyne-Bridged Pyridinophane and Tropylium Cation STM & Guest Inclusion Ability My Work Summary 21

Purpose of My Work ・ Synthesis of butadiyne-bridged pyridino phane which possesses a larger cavity ・ Evaluation of its guest inclusion ・ Formation of two-dimensional (2D) molecular networks on the solid surface. ・ guest inclusion ability ＋ 22

Contents Host–Guest Chemistry About Macrocycle Complexation of Butadiyne-Bridged Pyridinophane and Tropylium Cation STM & Guest Inclusion Ability My Work Summary 23

Summary The tetragonal butadiyne-bridged pyridinophane and tropylium cation form the complex in solution. The binding constants of tetragonal butadiyne-bridged pyridinophane are larger than those of hexagonal. The tetragonal butadiyne-bridged pyridinophane also forms complex with tropylium cation on solid surfaces. A purpose of my work is to synthesize butadiyne-bridged pyridinophane which possesses a larger cavity and evaluate its guest inclusion. 24

Thank you for listening. 25