分子自己集合がどのようにして起こるのか？

　分子自己集合という現象が見つかって以来，この美しい現象がどのように起こるのかという，反応機構については長らく謎のままでした．我々の研究室では，2014年から自己集合性金属錯体を題材に，この問題に取り組み，QASAP (Quantitative Analysis of Self-Assembly Process)という独自の解析手法を開発し，これを利用して，これまでに，カプセル型，カゴ型，環状型などの自己集合体の形成機構を明らかにしてきました．これにより，多くの分子自己集合が通常の化学反応と異なり，様々な経路を経て進行することが明らかになりました．我々の研究室の目標は，多数の自己集合体の形成機構の解明を通して，分子自己集合を支配する原理をあぶり出すことです．自己集合性金属錯体の形成機構を調べている研究グループは世界で我々の研究室だけで，現在，QASAPを利用して世界中の研究者との共同研究を進めています．

分子自己集合の速度論コントロール

　分子自己集合は構成要素が可逆な結合や相互作用により集まっているため、一般的に熱力学的に支配されていると考えられています。熱力学支配における分子自己集合では、自己集合体の熱力学的安定性によってのみ決まり、最終的に到達する状態は自己集合過程に依存しません。一方、自然界には色々な構成要素からなる複雑な分子自己集合体が存在します。このような多成分の分子自己集合体の場合、各構成要素の数、組成、配列の異なるさまざまな異性体が生成し、これらのエネルギーが近くなり、熱力学支配によって、ある一種類の自己集合体を選択的に生成することが困難になります。分子自己集合が速度論で進行する場合、どのような経路で反応が進行するかによって得られる自己集合体が変化します。そのため、上手に経路を選択することができれば、エネルギーの近い多数の異性体の中からある1種類を選択的に形成することが可能になります。また、速度論支配では生成物の分布は異性体の安定性に依存しないため、最安定ではない（準安定な）構造体を主生成物にすることもできます。現在、我々の研究室では、自己集合過程の解明によって明らかになった知見を利用し、速度論支配における分子自己集合の一般原理や一般的な合成手法の開発に取り組んでいます。

104. Kinetically controlled narcissistic self-sorting of Pd(II)-linked self-assemblies from structurally similar tritopic ligands.

T. Abe, S. Horiuchi, and S. Hiraoka*

Chem. Commun. 58, 10829–10832 (2022). [DOI: 10.1039/d2cc04496j]

103. Cyclization or bridging: which occurs faster is the key to the self-assembly mechanism of Pd6L3coordination prisms. 

X. Zhang‡, S. Takahashi‡, K. Aratsu, I. Kikuchi, H. Sato, and S. Hiraoka*

Phys. Chem. Chem. Phys. 24, 2997–3006 (2022). [DOI: 10.1039/D1CP04448F] ‡: These authors equally contributed to this research.

H. Sato
Kyoto University

102. Unexpected self-assembly pathway to a Pd(II) coordination square- based pyramid and its preferential formation beyond the Boltzmann distribution.

T, Tateishi, S. Takahashi, I. Kikuchi, K. Aratsu, H. Sato, and S. Hiraoka*

Inorg. Chem. 60, 16678–16685 (2021). [DOI: 10.1021/acs.inorgchem.1c02570]

H. Sato
Kyoto University

98. Coordination Self-assembly Processes Revealed by Collaboration of Experiment and Theory: Toward Kinetic Control of Molecular Self-assembly.

S. Hiraoka*, S. Takahashi, and H. Sato

Chem. Rec. 21, 443 – 459 (2021). [DOI: 10.1002/tcr.202000124] (selected as Front Cover)

H. Sato
Kyoto University

97. Towards Kinetic Control of Coordination Self-Assembly: A Case Study of a Pd3L6 Double-Walled Triangle to Predict the Outcomes by a Reaction Network Model. 

S. Takahashi,* T. Tateishi, Y. Sasaki, H. Sato, and S. Hiraoka*

Phys. Chem. Chem. Phys. 22, 26614 – 26626 (2020). [DOI: 10.1039/d0cp04623j]

H. Sato
Kyoto University

96. Navigated Self-assembly of a Pd2L4 Cage by Modulation of an Energy Landscape under Kinetic Control.

T. Tateishi, S. Takahashi, A. Okazawa, V. Martí-Centelles, J. Wang, T. Kojima, P. J. Lusby,* H. Sato, and S. Hiraoka*

J. Am. Chem. Soc. 141, 19669 – 19676 (2019). [DOI: 10.1021/jacs.9b07779]

P. J. Lusby University of Edinburgh, UK
H. Sato
Kyoto University

95. Bifurcation of Self-assembly Pathways to Sheet or Cage Controlled by Kinetic Template Effect

L. H. Foianesi-Takeshige, S. Takahashi, T. Tateishi, R. Sekine, A. Okazawa, W. Zhu, T. Kojima, K. Harano, E. Nakamura, H. Sato, and S. Hiraoka*

Commun. Chem. 2, 128 (2019). [DOI: 10.1038/s42004-019-0232-2] プレスリリース[Link]、Press release [Link]

E. Nakamura
the University of Tokyo
K. Harano
the University of Tokyo
H. Sato
Kyoto University

91. Self-assembly Processes of Octahedron-shaped Pd6L4 Cages. 

S. Komine, S. Takahashi, T. Kojima, H. Sato, and S. Hiraoka*

J. Am. Chem. Soc. 141, 3178 – 3186 (2019). [DOI: 10.1021/jacs.8b12890]

H. Sato Kyoto University

90. Self-assembly Process of a Pd4L8 Quadruply Interlocked Cage.

 T. Tateishi, Y. Yasutake, T. Kojima, S. Takahashi, and S. Hiraoka*

Commun. Chem. 2, 25 (2019). [DOI: 10.1038/s42004-019-0123-6] プレスリリース[Link]、日本経済新聞電子版 [Link]

88. Self-assembly Processes of Pd6L12 Cages.

S. Komine, T. Tateishi, T. Kojima, H. Nakagawa, Y. Hayashi, S. Takahashi, and S. Hiraoka*

Dalton Trans. 48, 4139 – 4148 (2019). [DOI: 10.1039/C8DT04931A] selected as Inside Front Cover and Hot Paper

87. Self-assembly Processes of Pd(II)- and Pt(II)-linked Discrete Self-assemblies Revealed by QASAP.

S. Hiraoka*

Isr. J. Chem. 59, 151 – 165 (2019). [DOI: 10.1002/ijch.201800073](Invited Account)

86. A Stochastic Model Study on the Self-Assembly Process of a Pd2L4 Cage Consisting of Rigid Ditopic Ligands.

 S. Takahashi*, Y. Sasaki, S. Hiraoka*, and H. Sato*

Phys. Chem. Chem. Phys. 21, 6341 – 6347 (2019). [DOI: 10.1039/C8CP06102E] selected as Outside Back Cover

H. Sato
Kyoto University

85. A Kinetics Study of Ligand Substitution Reaction on Dinuclear Platinum Complexes: Stochastic Versus Deterministic Approach

T. Iioka, S. Takahashi, Y. Yoshida, Y. Matsumura, S. Hiraoka, and H. Sato*

J. Comput. Chem. 1, 279 – 285 (2019). [DOI: 10.1002/jcc.25588]

H. Sato
Kyoto University

84. Self-Assembly of a Pd4L8 Double-Walled Square Takes Place through Two Kinds of Metastable Species. 

S. Kai, T. Tateishi, T. Kojima, S. Takahashi, and S. Hiraoka*

Inorg. Chem. 57, 13083 – 13086 (2018). [DOI: 10.1021/acs.inorgchem.8b02470]

キラルセルフソーティング の機構:どのようにエナンチオマーの選別が起こるのか

立石 友紀・小島 達央・平岡 秀一

現代化学, 9月号(570), 64–68 (2018).

80. Two Dominant Self-assembly Pathways to a Pd3L6 Double-walled Triangle.

 T. Tateishi, S. Kai, Y. Sasaki, T. Kojima, S. Takahashi, and S. Hiraoka*

Chem. Commun. 54, 7758 – 5561 (2018). [DOI: 10.1039/C8CC02608D]]selected as Back Cover

78. Energy-Landscape-Independent Kinetic Trap of Incomplete Cage in the Self-assembly of a Pd2L4 Cage.

M. Nakagawa, S. Kai, T. Kojima, and S. Hiraoka*

Chem. Eur. J. 24, 8804–8808 (2018). [DOI: 10.1002/chem.201801183] selected as Hot Paper and Inside Cover

74. How Does Chiral Self-sorting Take Place in the Formation of Homochiral Pd6L8 Capsules Consisting of Cyclotriveratrylene-based Chiral Tritopic Ligands?

S. Kai, T. Kojima, F. L. Thorp-Greenwood, M. J. Hardie, and S. Hiraoka*

Chem. Sci. 9, 4104 – 4108 (2018). [DOI: 10.1039/C8SC01062E]

M. J. Hardie
University of Leeds, UK

73. Unresolved Issues that Remain in Molecular Self-Assembly. 

S. Hiraoka*

Bull. Chem. Soc. Jpn. 91, 957–978 (2018). [DOI: 10.1246/bcsj.20180008] Commemorative Accounts: Self-Organization

71. Chiral Self-sorting Process in the Self-assembly of Homochiral Coordination Cages from Axially Chiral Ligands. 

T. Tateishi, T. Kojima, and S. Hiraoka*

Commun. Chem. 1, 20 (2018). [DOI: 10.1038/s42004-018-0020-4]. プレスリリース [Link] 日本経済新聞電子版 [Link]

68. Flexibility of Components Alters the Self-assembly Pathway of Pd2L4 Coordination Cages.

S. Kai, S. P. Maddala, T. Kojima, S. Akagi, K. Harano, E. Nakamura, and S. Hiraoka*

Dalton Trans. 47, 3258–3263 (2018). [DOI: 10.1039/C8DT00112J] selected as Outside Front Cover

66. Multiple Pathways in the Self-assembly Process of a Pd4L8 Coordination Tetrahedron.

T. Tateishi, T. Kojima, and S. Hiraoka*

Inorg. Chem. 57, 2686–2694 (2018). [DOI: 10.1021/acs.inorgchem.7b03085]

65. Chiral Effects on the Final Step of an Octahedron-Shaped Coordination Capsule Self-Assembly. 

Y. Matsumura, S. Iuchi, S. Hiraoka, and H. Sato*

Phys. Chem. Chem. Phys. 20, 7383–7386 (2018). [DOI: 10.1039/C7CP08237A] selected as Hot Paper and Back Cover

H. Sato
Kyoto University

64. Self-assembly of a Pd4L8 Double-walled Square Partly Takes Place through the Formation of Kinetically Trapped Species.

T. Tateishi, W. Zhu, L. H. Foianesi-Takeshige, T. Kojima, K. Ogata, and S. Hiraoka*

Eur. J. Inorg. Chem. 1192–1197 (2018). [DOI: 10.1002/ejic.201800037]

63. Self-Assembly Process of a Pd2L4 Capsule: Steric Interactions between Neighboring Components Favor the Formation of Large Intermediates

S. Kai, M. Nakagawa, T. Kojima, X. Li, M. Yamashina, M. Yoshizawa, and S. Hiraoka*

Chem. Eur. J. 24, 3965 3969 (2018). [DOI: 1002/chem.201705253] selected as Cover Feature

62. Quantitative Analysis of Self-Assembly Process of Hexagonal Pt(II) Macrocyclic Complexes: Effect of Solvent and Components. 

A. Baba, T. Kojima, and S. Hiraoka*

Chem. Eur. J. 24, 838–847 (2018). [DOI: 10.1002/chem.201702955] selected as Hot Paper, Front Cover and Cover Profile

61. Quantitative Analysis of Self-Assembly Process of a Pd2L4 Cage Consisting of Rigid Ditopic Ligands. 

S. Kai, V. Marti-Centelles, Y. Sakuma, T. Mashiko, T. Kojima, U. Nagashima, M. Tachikawa, P. J. Lusby, and S. Hiraoka*

Chem. Eur. J. 24, 663–671 (2018). [DOI: 10.1002/chem.201704285]

60. Quantitative Analysis of Self-assembly Process of a Pd12L24 Coordination Sphere. 

S. Kai, T. Shigeta, T. Kojima, and S. Hiraoka*

Chem. Asian J. 12, 3203–3207 (2017). [DOI: 10.1002/asia.201701351]

59. The Effect of Solvent and Coordination Environment of Metal Source on the Self-Assembly Pathway of a Pd(II)-mediated Coordination Capsule. 

S. Kai, Y. Sakuma, T. Mashiko, T. Kojima, M. Tachikawa, and S. Hiraoka*

Inorg. Chem. 56, 12652-12663 (2017). [DOI: 10.1021/acs.inorgchem.7b02152]

58. A Reaction Model on the Self-assembly Process of Octahedron-shaped Coordination Capsules. 

Y. Matsumura, S. Hiraoka, and H. Sato*

Phys. Chem. Chem. Phys. 19, 20338–20342 (2017). [DOI: 10.1039/c7cp03493h]

H. Sato
Kyoto University

55. What Do We Learn from the Molecular Self-Assembly Process?

S. Hiraoka*

Chem. Rec. 15, 1144-1147 (2015) [DOI: 10.1002/tcr.201510005]

54. Self-Assembly Process of Dodecanuclear Pt(II)-Linked Cyclic Hexagon.

A. Baba, T. Kojima, and S. Hiraoka

J. Am. Chem. Soc. 137, 7664-7667 (2015). [DOI: 10.1021/jacs.5b04852]

自己組織化の過程を調べる

平岡秀一

現代化学, 3, 30–35 (2015).

51. Rate-Determining Step in the Self-Assembly Process of Supramolecular Coordination Capsules. 

Y. Tsujimoto, T. Kojima, and S. Hiraoka* 

Chem. Sci. 5, 4167-4172 (2014). [DOI: 10.1039/C4SC01652A] selected as Back Cover