Cover Feature: Square Planar Coordination of Silver in a η4‐Cyclobutadiene‐(η5‐C5H5)ReBr2 Complex Framework (Z. Anorg. Allg. Chem. 21/2018).

The cover picture shows a (distorted) square planar bromide coordination environment about a silver cation. The application of soluble silver salts for halide abstraction is a common preparative routine in organometallic chemistry. If the oxidation power of Ag+ is restricting, respective thallium salt can be an alternative. The paper of Kleinschmidt et al. presents polynuclear ReIII/AgI complexes, in which the contest between both metals for the bromide or even iodide ion remains undecided. Consequently, the cyclobutadiene complexes [(η5‐C5H5)(η4‐C4Ph4)ReX2] (X = Br, I) act as neutral halide ligands for Ag+ leading to molecular complexes. Interestingly, the organometallic scaffold of the Re complex moieties forces a square planar coordination. In addition, reversible rhenacyclopentatriene /η4‐cyclobutadiene rearrangement by successful bromide addition/abstraction is presented for sulfide‐substituted congeners. More details can be found in the article by Steffen Kleinschmidt, Alexander Hinz, Alexander Villinger, and Wolfram W. Seidel on page 1268 ff. [ABSTRACT FROM AUTHOR]