Electron withdrawing groups, such as nitro and nitrile groups, up-shift the redox potential and make the polymer more oxidizing. In general, the preferred ring substituents are not bulky, do not ionize to form anions, but may be protonated to form cations, and are not reactive. Preferred ...
Examples of suitable electron-withdrawing groups are: C=O, SO.sub. 2, -C=N, -NO.sub. 2, -N.sub. 3, monovalent aromatic group, e.g., a phenly group and a -O-CO-R group in which R is an organic group, e.g. an alkyl group, an aryl group or a heterocyclic group. A suita...
In our previous work, we reported a modification of the pincer ligand structure (Chart , structure CF3 Ir), introducing electron-withdrawing trifluoromethyl groups to the aromatic backbone.5 In comparison to the unsubstituated POCOP structure (Chart , structure H Ir) originally reported by Brookh...
But the trends in catalyst activity and stability over the diverse electron-donating and electron-withdrawing ligands were complicated by the existence of substituent-specific effects of these groups. Chen et al. investigated the ligand electronic effects of α-diimine Ni(II) catalysts (Chart 1VII)...
If the rotating speed is less than this range, the quality of the resulted ingot has almost no difference compared with the quality of the ingot which is cast only by withdrawing down in a very slow speed with the weight of the formed ingot itself. As shown in FIG. 7, the electron ...