INDEX ligand substitution

Three main parameters were used to evaluate the efficiency of the polymerization, namely monomer conversion (Cmma), initiation efficiency of the reaction (/ = Mn theo/3 n,SEc), and polydispcrsity index (PDI). These results are depicted in Fig. 2. It is obvious that the Cu(I)-catalyzed systems are more effective than the Fe(II)-catalyzed systems under the studied conditions. It was concluded that a bipyridine based ligand with a critical length of the substituted alkyl group (e.g., dHbpy) shows the best performance in Cu(I)-mediated systems. Besides, Cu(I) halide-mediated ATRP with 4,5 -Mbpy as the ligand and TsCl as the initiator was better controlled than that with dMbpy as the ligand, and polymers with much lower PDI values were obtained in the former case. 

The terminally substituted diphosphines have also been used to prepare Au complexes (16-18, Chart 5.4) [37]. The metal does not shift the absorption maxima much relative to the free ligands however, dual emission is observed in the case of 17. This is attributed to emission from both monomer and an Au-Au bridged dimer, which is observed in the solid state. Several of the Pt and Pd complexes (19-24, Chart 5.4) have also been characterized crystallographically and some of these structures show k-k stacking interactions between thiophene rings in the solid state [38]. A third-order nonlinear optical response was obtained for the Pd and Pt complexes (21 and 24) using Z-scan measurements [39]. These complexes have nonlinear refractive index values of (—1.5 to —1.8) Hicks and co-workers have prepared a... 

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