Cavitand-Based Pd-Pyridyl Coordination Capsules: Guest-Induced Homo- or Heterocapsule Selection and Applications of Homocapsules to the Protection of a Photosensitive Guest and Chiral Capsule Formation
著者
和文:
M. Nakamura,
Y. Tsukamoto,
T. Ueta,
Y. Sei,
福島 孝典,
K. Yoza,
K. Kobayashi.
英文:
M. Nakamura,
Y. Tsukamoto,
T. Ueta,
Y. Sei,
T. Fukushima,
K. Yoza,
K. Kobayashi.
A 2 : 4 mixture of tetrakis[4‐(4‐pyridyl)phenyl]cavitand (1 ) or tetrakis[4‐(4‐pyridyl)phenylethynyl]cavitand (2 ) and Pd(dppp)(OTf)2 self‐assembles into a homocapsule {1 2 ⋅ [Pd(dppp)]4}8+ ⋅ (TfO−)8 (C1 ) or {2 2 ⋅ [Pd(dppp)]4}8+ ⋅ (TfO−)8 (C2 ), respectively, through Pd−Npy coordination bonds. A 1 : 1 : 4 mixture of 1 , 2 , and Pd(dppp)(OTf)2 produced a mixture of homocapsules C1 , C2 , and a heterocapsule {1 ⋅ 2 ⋅ [Pd(dppp)]4}8+ ⋅ (TfO−)8 (C3 ) in a 1 : 1 : 0.98 mole ratio. Selective formation (self‐sorting) of homocapsules C1 and C2 or heterocapsule C3 was controlled by guest‐induced encapsulation under thermodynamic control. Applications of Pd−Npy coordination capsules with the use of 1 were demonstrated. Capsule C1 serves as a guard nanocontainer for trans‐4,4′‐diacetoxyazobenzene to protect against the trans‐to‐cis photoisomerization by encapsulation. A chiral capsule {1 2 ⋅ [Pd((R )‐BINAP)]4}8+ ⋅ (TfO−)8 (C5 ) was also constructed. Capsule C5 induces supramolecular chirality with respect to prochiral 2,2′‐bis(alkoxycarbonyl)‐4,4′‐bis(1‐propynyl)biphenyls by diastereomeric encapsulation through the asymmetric suppression of rotation around the axis of the prochiral biphenyl moiety.
各種検索
サポート
ヘルプ