Macromolecular Conjugated Complexes

An efficient redox process of transition metal complexes for electron transfer 

Furthermore, when ligands bear more than two coordination sites, interaction between metals can occur through the ligand spacer (Fig. 3.9). This design is 

---

Macromolecular Conjugated Complexes 171 [ 7C-Conjugated polymer - Metal ]o ... 

Researchers have accumulated a large body of thermodynamic and kinetic data to assess these effects, and many of these results are included in the tables of reference 101. Qualitatively, one concludes that for small molecule Gd(III) complexes—those of molecular weight<1000 Da—a high relaxivity, measured in mM 1 s 1, will approach an upper limit of 5 mM-1s-1. Some data are collected in Table 7.3. Newer macromolecular conjugate-Gd(III) complex systems, also discussed below, may approach relaxivities five to six times larger per Gd(III) ion. 

Given the vastness of the subject matter I have limited myself to dealing with the structural (or static) aspects of macromolecular stereochemistry. An adequate treatment of the stereochemistry of polymerization, with specific regard to the polymerization of olefins and conjugated diolefins, would have occupied so much space and called for such a variety of additional information as to make this article excessively long and complex. I trust that others will successfully dedicate themselves to this task. However, the connection between polymer structure and polymerization mechanism is so important that the fundamentals of dyruunic macromolecular stereochemistry cannot be completely ignored in this chapter. 

The system of conjugated double bonds responsible for carotenoid colors also helps to impart specific shapes to these largely hydrophobic molecules and ensures that they occupy the appropriate niches in the macromolecular complexes with which they associate. Information on stereochemistry is provided in a short review by Britton.138... 

Electrophiles not only complex with macromolecular nucleophilic sites, but also complex with those of small molecules. The most important of these is the -SH group of GSH. Conjugation of electrophiles with GSH is an important detoxication reaction catalyzed by GSH transferases (see Chapter 12). Although GSH concentration in hepatocytes is high relative to other tissues (4-8mM), depletion of GSH can occur upon acute exposure to protoxicants whose electrophilic metabolites... 

Developments in supramolecular chemistry provide a number of very intriguing examples of rather complex, but nevertheless well-defined, hydrogen bonded superstructures which present new building blocks for conjugation with macromolecular systems. Figures 36a and b give two examples of finite assemblies based on... 

---