Scanning tunnelling microscopy (STM) and molecular dynamics (MD) simulations have been used to investigate the implantation of Ag − 7 clusters into the graphite surface. An experimental measure of the implantation depth of individual clusters is gained via thermal oxidation of the bombarded graphite surfaces. This process results in etching of the cluster-induced defects to form etch pits which grow laterally whilst retaining the depth of the implanted cluster. STM imaging of the etch pits reveals the distribution of implantation depths for deposition energies of 2 keV and 5 keV. Molecular dynamics simulations for clusters of 5 keV energy show that the implantation depth for Ag − 7 is largely independent of the impact site on the graphite surface and the cluster orientation. The implantation depth found by MD lies at the upper edge of the experimental depth distribution.PACS. 36.40.-c Atomic and molecular clusters -68.37.Ef Scanning tunnelling microscopy (including chemistry induced with STM) -02.70.Ns Molecular dynamics and particle methods

A series of bis‐[3]ferrocenophanes of the general type Fe(C5H4E’)2E−E(E'C5H4)2Fe (E=P, SiH and E’=PtBu, NneoPentyl, NSi(CH3)3) with an isolobal molecular framework have been prepared and characterized by heteronuclear NMR spectroscopy and X‐ray crystallography. The thermal dissociation behavior with respect to homolytic fission of the central bond generating phosphorus centered radicals was investigated using EPR spectroscopy and quantum chemical calculations.

Reactions of P-chloro-1,3,2-diazaphospha-[3]ferrocenophanes with ECl3 (E = Al, Ga) under solvent-free conditions and with Na[Mn(CO)5] furnished salts featuring a ferrocenophane-based phosphenium cation or neutral phosphenium complexes, respectively. All products were characterized by spectroscopic studies. Single-crystal X-ray diffraction studies confirmed the ionic nature of the phosphenium tetrachloroaluminate and the structural analogy between the phosphenium complexes and Fischer-type carbene complexes. Distinct deviations in the conformation of the ansa-bridge suggest electronic stabilization of the electrophilic phosphorus atom by phosphorus-nitrogen π-interactions in the free cation and by phosphorus-metal π-bonding in the complexes. The observation of short intermolecular contacts in the crystalline phosphenium salt and its chemical behavior towards donor solvents attest the cation an unusually high degree of Lewis-acidity, which was confirmed by DFT studies and related to the presence of a rather large N-P-N angle. Computational studies indicate further that the free phosphenium cation exhibits a closed-shell electronic structure with a formal Fe(II) oxidation state and is thus a true analogue to ferrocenophane-based diaminotetrylenes.

Condensation of 1,1′-diaminoferrocenes with PCl3 gives access to P-halo-diazaphospha-[3]ferrocenophanes and [4]ferrocenophane-annelated tetraphosphetanes, which can undergo multiple oxidation in both ferrocene and aminophosphine units.

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.