Inside Cover: hallium(I) as a Coordination Site Protection Agent: Preparation of an Isolable Zero‐Valent Nickel Tris‐Isocyanide (Angew. Chem. Int. Ed. 19/2009)

Binding of thallium(I) by low‐valent nickel establishes the use of main‐group ions as coordination site protection agents for transition‐metal centers. As described by J. S. Figueroa and co‐workers in their Communication on page 3473 ff. , Tl(I) coordination provides a route to the preparation of a coordinatively unsaturated nickel tris‐isocyanide complex. Thallium functions as a protecting group towards Lewis bases and is readily removed upon addition of halide ions.