Didentate

What happens if we look at the K2 or Ki, values for didentate ligands In general, the Kj values show stability patterns which closely parallel those for K. However, the values are different. Figure 8-17 presents K, data for transition-metal complexes of 1,10-phenanthroline and 1,2-diaminoethane (Eq. 8.14). 

Mononuclear complexes containing didentate N,N-donor ligands other than bpy or phen... 

The versatility of the quinolyl derivative (295) is exemplified in the complex [Ru(295-A,A )(295-A,A, A")C1]. The coordination behavior of (295) has been compared with those of (296) and (297) and factors influencing didentate vs. tridentate preferences have been examined. Perchlorate salts of [Ru(tpy)L)] " and [RUL2] where L = (298)-(300) have been synthesized and characterized, and their properties compared with those of [Ru(tpy)2] ". Complexation of Ru with 2,6-bis(4 -phenyl-2 -quinolyl)pyridine (L) affords [RUL2] , spectrosccmic properties of which have been discussed. " The bis(7 -methyl)-derivative of this ligand, L, has also been prepared and incorporated into the complexes [M(L )2f, [ (L CIs] (M = Ru, Os), and [Ru(L )(tppz)] + where tppz = 2,3,5,6-tetra(2 -pyridyl)pyrazine. Related cyclometallated complexes have also been studied. All the complexes luminesce at 77 K and [M(L )2] (M = Ru or Os), [Ru(L )(L )] , and two of the cyclometallated species are luminescent at room... 

Designing potential DNA intercalators has led to an investigation of a series of [Ru([9]aneS3)LCl] complexes where L is a didentate polypyridyl ligand. Structural data for the complexes are discussed in terms of hydrogen-bonded interactions and rr-stacking between extended aromatic systems, e.g., dppz and 4,7-Ph2phen. " ... 

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