Isolation of a Donor-Acceptor Superphane with a Quinone and a CpCo- Cyclobutadiene Unit.

The reaction of cyclodeca-1,6-diyne with η5-cyclopentadienylcobaltdicarbonyl not only yields the cyclobutadiene-derivatives 2 and 3 but also the fourfold bridged donor-acceptor superphane 4 as a side product.