Chelate ring nine-membered

The T1(1,2-C2H4C12)+ cation comprises a five-membered chelate ring and the Tl+ is weakly bonded to four B(OTeF5)4 anions with nine T1—F interactions. 

Complex 101 affords an unusual nine-membered chelate ring, with a C2 pseudo-axis of symmetry along the Au(I)—Cl bond199. 

It is worth noting that nickel(II) and copper(II) complexes of L193-L195 with seven- to nine-membered chelate rings undergo transamination processes when... 

Seven-, Eight-, and Nine-Membered Chelating Ring Systems... 

The complexes formed by oxalic and malonic acids have been carefully studied and the detailed structural features have been obtained from X-ray diffraction measurements (Hansson, I973e). The oxalate ions in these complexes serve as bridging ligands and the larger metal ions have coordination number nine whereas the smaller ions have coordination number eight. The malonate ions in the rare earth malonates are of two different types, those that are involved in six-membered chelate ring formation and those which are not. 

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