Chemical Modification of Polyacetylene by Diels-Alder Reactions

Abstract

Polyacetylene may be chemically modified by the Diels-Alder reaction. Standard reagents provide only modest conversions but the reaction with 4-methyl-1,2,4-triazoline-3,5-dione provides conversions up to 18 mole %, corresponding to the occupation of nearly of the carbon centres of polyacetylenc. The insoluble adduct films were more brittle and had electrical conductivities (after doping with iodine) which were inferior to those of the starting films.

Some potential Diels-Alder dienophiles (quinones) acted merely as p-dopants, enhancing the conductivity of standard N-(CH)_X.

Spin label introduction into the polyacetylene was at best carried out by an indirect addition, the addition of 4-amino-TEMPO to maleic anhydride modified polyacetylene, leading to an incorporation of up to 1.4 mole %.

Key Words:

• polyacetylene
• modification
• nitroxyl
• Diels-Alder
• conductivity
• doping