Cyanide-bridged complexes building block approach

A nontrivial synthetic approach to multinuclear cyanide-bridged clusters was developed by Comba and co-workers (208), who used ligand XXII capable of encapsulating up to three Cu(II) ions inside the cyclam macrocycles connected to the central triazine ring. In this case, the very nature of the building block promotes the formation of high nuclearity complexes. Indeed, when the [Cu°3(XXII)] ... 

A simpler but equally effective approach has been employed by Ward and coworkers [25] in the preparation of coordination polymers using luminescent anionic complexes. Here transition metals with emissive MLCT states act as effective sensMsers for lanthanide emission in the NIR [25]. In this case cyanide groups were used as bridging units starting from stable Ru " complexes and simple Ln salts. Examples include [Ru(Bipy)(CN)4] [26,27], [Ru(Phen) (CN)4] - [28], [Ru(Bpym)(CN)4] -, [Ru(CN)4]2([i-Bpym) 4- [29], [Ru(Hat)(CN)4] - [25], [Ru(CN)4]3(p"-Hat) -, [ Ru(CN)4 2([i -Hat)]4-, [Cr(CN)6]"-, and [Co(CN)6] - [30]. The advantage of this method is that the building blocks are already kinetically stable in solution and the solid structure is dictated by the coordination number adopted by the lanthanide ion (Fig. 9.5). 

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