MICROSTRUCTURE OF COPPER(II) ALPHA,OMEGA-DICARBOXYLATO POLYBUTADIENE

alpha , omega -Dicarboxylato polybutadiene has been neutralized to varying extents below stoichiometry by using Cu**2** plus isopropoxide under anhydrous conditions. These samples have been characterized by extended X-ray absorption fine structure (EXAFS) measurements and by magnetic measurements and electron paramagnetic resonance (e. p. r. ). It is deduced from EXAFS data by comparison with Cu(II) acetate that part of the copper ions are present as dimeric Cu-Cu complexes, which bond to the ends of four polybutadiene chains. A detailed description of these complexes has been obtained from e. p. r. results. The relative percentages of these different species (isolated Cu**2** plus and dimers) are given from the static magnetic measurements.