Pyrazabole polymers

Ferrocene-bridged tris(l-pyrazolylborate) oligomeric systems have been synthesized by Wagner and co-workers.62 The examples are described in more detail in the section on pyrazolylborate and pyrazabole polymers in this chapter. 

A,7V-polyazolylmethanes can be prepared by reaction of azoles with methylene chloride in an autoclave at 150 °C (Scheme ll).20 At 200 °C this reaction leads to 4,4 -dipyrazolylmethane, which upon reaction with boranes gives a pyrazaboles polymer. Some derivatives have been prepared from the reaction of potassium salts of the azole and methylene iodide. The ligand (tetrakis-(l-pyrazolyl)methane was prepared analogously. In selected cases a basic medium was employed.21... 

The area of organoboron polymers containing borazine and its derivatives is covered in Chapter 5 of this book by Miele and co-workers. Miele and Bernard also describe the utilization of these polymers in ceramics, fibers, and so on, in Chapter 3 of this book. In this section, the utilization of polymers containing borazine or in some cases the bicyclic boron ligand, 9-BBN, for the production of SiC or Si/C/B fibers is briefly described. Recent advances in polypyrazolylborate or pyrazabole-containing polymers and other boron ring system-derived polymers also have been briefly described. 

Hi. Organoboron Polymers that Contain Polypyrazolylborate or Pyrazabole Ring Systems... 

Over 2000 papers have appeared on the chemistry of polypyrazolylborate/ pyrazabole ring systems, but there have only been a few examples of polymers containing these ligands.112... 

Figure 50 Fluorescent organoboron polymers (81) obtained by Heck-Sonagashira coupling between diyne monomers and pyrazabole derivatives. (Adapted from ref. 115.)...

Organoboron polymers containing transition metals (Ni, Pd, Pt) and pyrazaboles were obtained by Cu-catalyzed coupling polymerization. The Ni- and Pt-containing polymers showed MLCT (metal-to-ligand charge transfer) absorption.78... 

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