Terphenyl Derivatives of. s-Block Elements

After the halide starting materials themselves, the alkali metal salts are the most important terphenyl compounds. This is a result of their widespread and almost exclusive use as transfer agents for terphenyl ligands. They can be synthesized by the simple reaction of n-BuLi with the halide (usually bromide or iodide). This general reaction, 

The sole heavier alkali metal derivative of a terphenyl ligand is the compound (NaC6H3-2,6-Mes2)2.35 It was synthesized by the reaction of its lithium congener with 

NaO-FBu as shown in Eq. (2). Its structure (Fig. 6) resembles that seen for the lithium dimer (LiC6H3-2,6-Mes2)2. However, in this case the metal ion (Na+) interacts almost equally (Na(l)-C(l) = 2.572(2) A, 

At present, only two organomagnesium derivatives of terphenyl ligands have been well characterized. However, the first terphenyl magnesium compound was reported more than 60 years ago with the generation of BrMgTriph in solution and its subsequent reactions to give the carboxylic acid, the acetyl derivative, and triphenylbenzophenone.28 

Currently, no terphenyl derivatives of the heavier group 2 elements, calcium, strontium, or barium have been well characterized. 

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