Octahedral complexes skew-lines convention

Skew-line convention for octahedral complexes. The second is the skew line convention and applies to octahedral complexes. Tris(didentate) complexes constitute a general family of structures for which a useful unambiguous convention has been developed based on the orientation of skew lines which define a helix. Examples I and 2 represent the della and lambda forms of a complex, such as [CofNHjCHjCHjNHj)]. ... 

Application of the skew-lines convention to tris(bidentate) octahedral complexes... 

The second is based on the geometry of the molecule and makes use of the skew-lines convention it is usually applied only to octahedral complexes. The two enantiomers are identified by the symbols A and A in this system. The C/A nomenclature is not required for those chelate complexes where the skew-lines convention is completely unambiguous (see Sections IR-9.3.4.11 to 9.3.4.14). 

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