1 3 4 , 2 5 6 Scheme 1 comparison, the splitting (An) between the first two bands in cyclohexane-1,4-dione is 0.1 eVf4], and in bicyclo[3.3.O]octane-3,7-dione 0.33 eV1.
Surprisingly, the template effect of a hydrocarbon has been detected for the first time: the yield in the one‐pot synthesis of the tetracationic macrocycle 1c is raised from 3–5% to 16% when excess phenanthrene is present. The new phane‐like tetracations 1a‐c and 2a‐c act as π‐acceptor host compounds and take up arenes as π‐donors in their cavities in a sandwich‐like manner.
The complexation properties of the title species (IVb) and (Vb) which act as π‐acceptor host compounds toward a series of arene donors such as (X)‐(XIII) are investigated in detail and compared with the respective behavior of the compounds (IVa), (Va), (VI)‐(IX).
form die exo-2-Brom-und exo,exo-2,6-Dibromderivate 2 bzw. 3 in 60 bzw. 70% Ausbeute. Die transanulare Eliminierung von HBr aus 2 zu 5 gelingt rnit Diazabicyclo[5.4.0]undecen (DBU) in wasserfreiem Acetonitril bei 50 "C unter N2 (70%, Fp = 140-142 "C). 3 liil3t sich in einem Schritt mit DBU in 6 umwandeln (80%, Fp=145-147 "C) oder in zwei Schritten iiber 4.
Der Templateffekt eines Kohlenwasserstoffs konnte überraschend erstmals nachgewiesen werden: Bei der Eintopfsynthese des tetrakationischen Makrocyclus 1c steigt die Ausbeute von 3–5% auf 16%, wenn Phenanthren im Überschuß zugegen ist. Als neue π‐Acceptor‐Wirtverbindungen nehmen die phanartigen Tetrakationen 1a–1c und 2a–2c Arene als π‐Donoren sandwichartig in ihren Hohlraum auf. magnified image
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