Conjugated ligands

Joachim C, Launay JP, Woitellier S (1990) Distance dependence of the effective coupling parameters through conjugated ligands of the polyene type. Chem Phys 147 131... 

To create pure red phosphorescent emission, a systematic study of the ligand structure and the emission properties was carried out by Tsuboyama et al. (Scheme 3.85) [304], It was found that the red-shift of the phosphorescence is attributable to introduction of more conjugated ligands. 

An interesting kind of interaction between a terminal group and the central metal ion has been observed by Fraser and Taube (32). As shown in Equation 52, the oxidation of a conjugated ligand at its furthest extremity from a metal ion may still involve participation by the electrons of the central metal ion by some conduction process. Participation of the central metal ion appears to be limited to reactions involving one-electron oxidants. 

The synthesis by Mueller-Westerhoff and Alscher150 of the Ni, Pd and Pt dithiomalonaldehyde ( ptt ) complexes allowed the comparison of NMR chemical shift data between the parent even and odd systems with sulfur-containing conjugated ligands. The results are given in Table 2. 

Great attention has been paid to the synthesis and photophysical properties of dinuclear ruthenium complexes containing bridging Jt-conjugaled ligands [24],... 

Z Biological macromolecules (albumin or albumin-enzyme conjugates both with and without conjugated ligands) cross the endothelial cell monolayer following the movement of neutrophils bat also independent of the neutrophils and without any receptor dependency. 

Type I Xenobiotic + reactive conjugating ligand = conjugated product... 

The second type of conjugation reaction involves the coupling of the endogenous conjugating ligand with a high-energy or reactive xenobiotic. The reactivity associated with the xenobiotic is sometimes the consequence of Phase I biotransformation (e.g., epoxidation, Chapter 10). 

In this copper complex, there is one weak point the chiral centers that exist in (R,R)-diop are distant from the dmp ligand on which an excited electron mainly exists. This means that the reaction site is far from the chiral center. It is desirable to introduce the chiral center on the conjugated ligand, like menbpy. However, we need to remember that the methyl or phenyl substituents should be introduced to the neighbor positions to the coordinating sites. Thus menbpy and PhEtbpy,... 

As a tridentate conjugated ligand this would be expected, like 2,2 -bipyridyl and 1,10-phenanth-roline, to stabilize osmium(II) and this is indeed the case, with most of the reported complexes containing divalent osmium. The unsubstituted bis complex [Os(terpy)2]2+ is remarkably stable. It seems likely that terpyridyl complexes of osmium(II) are good candidates for further investigation as photosensitizers, having so far received less attention than the corresponding bipyridyl or phenanthroline species. 

The size of the hole greatly influences the properties of the complex relative to those of open chain analogues and cavity sizes can now be related to ligand structure for both nonconjugated and conjugated ligands. 

---