Monosubstituted squarate complexes ligands

Complexes of Monosubstituted Squarate Derivatives A. Complexing Properties of Monosubstituted Squarate Ligands Substituents with Lone Pairs Substituents without Lone Pairs Effects of Substituent on Structure Squarate and Monosubstituted Squarate Complexes with jt Interactions... 

The reduction in the number of potential coordination sites from four to three on monosubstitution of squaric acid restricts the variety of possible coordination modes possible for these hgands. In the majority of the complexes prepared by HaU et al., the monosubstituted squarate ligands adopt a /u.-l,3 role, although in a few instances the ligands coordinate monodentately, adopting a pendant role 111, 123,132-137). Expectedly, as a consequence of bite-parameter considerations, chelation is observed only in the case of the large lead(II) ion (76). In... 

The structures of the complexes of monosubstituted squarate ligands are also dependent on the orientation of the substituent with respect to the ligating oxygen atom. For example, in the monomeric species M(CH3C403)2(H20)4 (M = Mn, Co, Cu, Zn) (132), the methyl substituent is oriented trans to the ligating oxygen atom on both methylsquarate... 

Hall et al. observed that in the complexes of monosubstituted squarate ligands, the ligands, invariably utilize all the hydrogen-bonding... 

---