Tridentate facially chelating

A.N. Vedernikov and co-workers designed and synthesized tridentate facially chelating ligands of the [2.n.1]-(2,6)-pyridinophane family. The key step in their synthesis of these tripyridine macrocycles was a double Chichibabin-type condensation of 1,2-b/s(2-pyridyl)ethanes with lithiated 2,6-dimethylpyridines. 

A more complex intramolecular hydrogen bond system is built in the platinum(II) complex 33 (O Fig. 8) in which the central f/trco-configured diol is the chelation site. A y and a S hydrogen bond, each starting at one of the terminal donor hydroxyl functions, end at one and the same alkoxido function. The other one is an acceptor in a more strained p hydrogen bond [22]. Affirmed by DPT calculations, the completion of an octahedral coordination sphere of trimethyl-platinum(n) in a dinuclear complex is accomplished with facial tridentately bonded D-mannitol (coordination mode , 0, 0 k 0, 0, 0 ) [38]. 

In the 2D polymer [Cd3(IDA)3(H20)]-3H20 n [138] the iminodiacetate dianions behave as tridentate chelating ligands and show both facial and meridional... 

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