Tris complexes, skew-lines

FIGURE 5.6 Definition of the skew-line convention used to define the absolute configuration of tris- or bis(chelate) complexes and conformation of diamine chelates. 

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 absolute configurations of some octahedral complexes can be described using either the skew-line reference system (Section IR-9.3.4.11) or the C/A system. The first is used more commonly, but the C/A system is more general and may be used for most complexes. The skew-line reference system is only applicable to tris(bidentate), bis(bidentate) and closely related systems. 

Tris(bidentate) complexes constitute a general family for which a useful, unambiguous convention has been developed based on the orientation of skew lines which define a helix. 

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