SYNTHESIS, SOLUTION PROPERTIES AND CONVERSION OF HROLINE-ALT-(2',5'-DIHEXYL)-4,4''-P-TERPHENYLENE)S INTO SOLUBLE, WELL-DEFINED COPPER(I) AND SILVER(I) COMPLEX POLYMERS

Readily soluble throline-alt-(2/,5'-dihexyl)-4,4''-p-terphenylene) pre cursor polymers have been prepared via the Pd-catalyzed polycondensati on reaction of 2,9-bis(p-bromophenyl)-o-phenanthroline and 2,5-dihexyl benzene-1,4-diboronic acid. Cyclotrimerization has been found to be th e most important side reaction of this process which considerably lowe rs the yield of the precursor polymer when the coupling reaction is ca rried out at high dilution. However, cyclic oligomers could be separat ed off completely from the polymeric products by extraction with aceto ne. Subsequently, the constitutional homogeneity, the degrees of polyc ondensation, and the solution properties of the obtained polymers were analyzed using high-resolution NMR spectroscopy, osmometry, size-excl usion chromatography, viscosimetry and static light scattering. Finall y, diamagnetic transition-metal complex polymers of well-defined const itution have been prepared by treating the precursor polymers with cop per(I) and silver(I) compounds. Branching or crosslinking via the form ation of intermolecular [M(phen)(2)] complexes could be suppressed in this final conversion by the addition of an appropriate amount of an ' 'auxiliary ligand'' L or L-2 to the reaction mixtures: these latter li gands have been shown to reliably saturate the two remaining coordinat ion sites of every transition-metal center of the complex polymers whi ch are not occupied by the o-phenanthroline nitrogen atoms of the poly mer main chains.