Platinum complexes 1,8-naphthyridine

The JHNMR spectrum of the platinum 1,8-naphthyridine complex (124) shows the naphthyridine protons to be equivalent above -30 °C, suggesting fluxional behavior (77IC261). Other examples of this phenomenon have also been observed (73JA4855). 

Numerous other aromatic nitrogen compounds are known, and a significant number have been used to prepare complexes of platinum(II). Phthalazine (101) is one such compound, and the complex ds-PtCl(phthalazine)(PEt3)2 has been prepared in order to compare its fluxional properties with the phenanthroline and naphthyridine analogues. The monodentate complex is fluxional, but in this phthalazine case the orientation of the lone pairs is unsuitable for the five-coordinate intermediate required by an intramolecular process and the mechanism of exchange becomes dissociative.11 6... 

The platinum 1,8-naphthyridine complex (160) in the solid state shows square-planar coordination about platinum with the naphthyridine behaving essentially as a monodentate heterocycle.109... 

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