Bis‐[3]Ferrocenophanes with Central >E−E’< Bonds (E, E’=P, SiH): Preparation, Properties, and Thermal Activation

Invited for this month's cover picture are the groups of Professors Rudolf Pietschnig at the University of Kassel, Professor Dietrich Gudat at the University of Stuttgart and Professor László Nyulászi at the Budapest University of Technology and Economics. The cover picture shows the thermally induced homolytic cleavage of the central P‐P bond in a phosphorus–rich bis‐ferrocenophane furnishing P‐centered radicals (as evidenced by the computed spin‐density highlighted in blue). The central P6 unit in the title compound is a structural analog of the connecting unit in Hittorf's violet phosphorus, which links the orthogonally arranged tubular entities. A portrait of the German physicist Johann Wilhelm Hittorf is included. Read the full text of their Full Paper at 10.1002/open.201900182. “…We are amazed by the structural parallels between our bisferrocenophanes and the bridging units in Hittorf's violet phosphorus, which include even the bond length alternation pattern with the location of the shortest P‐P bond in the center of the scaffold. Surprisingly enough, it is this shortest P‐P bond in the molecule which acts as breaking point upon moderate heating….” Find out more about the story behind the front cover research at 10.1002/open.201900182.