| Abstract: | Mono‐ and dianions of 2‐tert‐butyl‐3a2‐azapentabenzobc,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 a 2?)2], revealed the presence of a naked dianion. In contrast, controlled reaction of 1 a with Cs allowed the isolation of singly and doubly reduced forms of 1 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 of 1 a ? is observed, whereas in {Cs+(18‐crown‐6)}2( 1 a 2?)], 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. |
