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Abstract Mono‐ and dianions of 2‐tert‐butyl‐3a2‐azapentabenzo[bc,ef,hi,kl,no]corannulene (1 a) were synthesized by chemical reduction with sodium and cesium metals, and crystallized as the corresponding salts in the presence of 18‐crown‐6 ether. X‐ray diffraction analysis of the sodium salt, [{Na+(18‐crown‐6)(THF)2}3{Na+(18‐crown‐6)(THF)}(1 a2−)2], revealed the presence of a naked dianion. In contrast, controlled reaction of1 awith Cs allowed the isolation of singly and doubly reduced forms of1 a, both forming π‐complexes with cesium ions in the solid state. In [{Cs+(18‐crown‐6)}(1 a−)]⋅THF, asymmetric binding of the Cs+ion to the concave surface of1 a−is observed, whereas in [{Cs+(18‐crown‐6)}2(1 a2−)], two Cs+ions bind to both the concave and convex surfaces of the dianion. The present study provides the first successful isolation and characterization of the reduced products of heteroatom‐containing buckybowl molecules.
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Twisted Diindeno‐Fused Dibenzo[ a , h ]anthracene Derivatives and their Dianions
Abstract We report a facile synthesis of diindeno‐fused dibenzo[a,h]anthracene derivatives (DIDBA‐2Cl,DIDBA‐2Ph, andDIDBA‐2H)with different degrees of non‐planarity using three substituents (chloro, phenyl, and hydrogen) of various sizes. The planarization of their cores, as evidenced by the decreased end‐to‐end torsional angles, was confirmed by X‐ray crystallography. Their enhanced energy gaps with twisting were investigated by a combination of spectroscopic and electrochemical methods with density functional theory, which showed a transition from singlet open‐shell to closed‐shell configuration. Moreover, their doubly reduced states,DIDBA‐2Ph2−andDIDBA‐2H2−, were achieved by chemical reduction. The structures of dianions were identified by X‐ray crystallographic analysis, which elucidated that the electron charging further distorted the backbones. The electronic structure of the dianions was demonstrated by experimental and theoretical approaches, suggesting decreased energy gaps with larger non‐planarity, different from the neutral species.
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- PAR ID:
- 10431948
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 62
- Issue:
- 34
- ISSN:
- 1433-7851
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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