Organometallic polycondensation

Yamamoto T Macromol Rapid Commun (2002) 23 583-606 n-Conjugated polymers with electronic and optical functionalities preparation by organometallic polycondensation, properties, and applications... 

JT-Conjugated Polymers Bearing Electronic and Optical Functionalities. Preparation by Organometallic Polycondensations, Properties and Their Application... 

Yamamoto T. TT-Conjugated polymers bearing electronic and optical functionalities preparation by organometallic polycondensations, properties, and their applications Bull. Chem. Soc. Jpn. 72, 621, 1999... 

Yamamoto T. Synthesis of ir-conjugated polymers bearing electronic and optical functionalities by organometallic polycondensations. Chemical properties and applications of the TT-conjugated polymers Synlett 425, 2003... 

Polyphenylenes with side chains or side rings have usually been prepared via organometallic polycondensation. Examples are shown in Schemes 4.10 and 4.11. 

Many monomers for organometallic polycondensation are commercially available, which include p- and nr-dihalobenzenes and diboronic compounds of benzene e.g., / -C6H4(B(OH)2)2 and its bis(pinacol) ester). Various dihalo-benzenes with substituents e.g., l,4-dibromo-2,5-dimethoxybenzene and 1,4-dibromo-2,5-dimethylbenzene) are also commercially available. However, some of the dihalobenzenes with substituents have to be synthesized, for example, using Br2 and V-bromosuccinicimide (NBS). 

Organometallic polycondensation is usually carried out under inert gas e.g., N2 and Ar) using the Schlenk technique. When the Ni complex is employed as the condensation agent or catalyst, dry solvents such as THF, DMF and toluene are used. 

Various Ni and Pd complexes can be used for the dehalogenative organometallic polycondensation. Ni complexes are reactive toward -C l, -C-Br and -C-I bonds. However, Pd complexes are usually not reactive to the -C Cl bond and the polycondensation is usually carried out with Br-Ar Br monomers. In the case of the polycondensation with Ni complexes, pseudo halogen compounds such as MsO Ar Ms are also usable as the monomer (cf. Example 10). 

The molecular weight of the r-conjugated poly (arylene)s prepared by organometallic polycondensation seems to depend on the solubility and crystallinity... 

Since organometallic polycondensation attains a n-conjugated poly(arylene) system with well-defined bonding between the recurring arylene units, the polymers are considered to assume interesting characteristics such as rigid linear and helical structures. 

Organometallic polycondensation processes based on basic organometallic chemistry [1] have contributed to the preparation of 7r-conjugated polymers and represent the first preparation of this kind (e.g. PTh and PRTh). The 7r-conJugated polymers prepared by organometallic polycondensation have a well-characterized structure and have contributed to our understanding of basic chemical and physical properties as well as elucidation of the structure of the 7i-conjugated polymers. In addition, they are useful materials for electric and optical devices and are expected to be invaluable in future applications. 

An example of organometallic polycondensation is illustrated by the reaction between dimethyltin dichloride and a diamine (Scheme 5). Again, the diamine acts as a Lewis base and the chloride and hydrogen are the leaving groups. Here, the nitrogen is covalently bonded after loss of the proton. This reaction is analogous to typical amide formation between diamines and diacid chlorides. 

Yamamoto T, Etori H (1995) Poly(anthraquinone)s having a jc-cmain chain. Synthesis by organometallic polycondensation, redox behavior, and optical properties. Macromolecules 28 3371-3379... 

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