Synthesis of OH-functionalized poly(p-xylylene)s by reductive coupling polymerization of aromatic dialdehydes with catalytic amounts of divalent samarium compounds

Abstract

The focus of this study is on reductive couplings of aromatic monoaldehydes and dialdehydes utilizing catalytic amounts of Sm(II) compounds and different co-reductants such as Mg turnings and Mg/Hg alloy in the presence of trimethylsilylchloride (TMSiCl). High educt and no side products have been observed using 10 mol% of SmI2 and excess of Mg turnings activated by C2H4Br2 in the presence of TMSiCl. Low yields of hydrobenzoin were observed when SmCp2 replaced SmI2. The reductive coupling polymerization of aromatic dialdehydes can be conducted under catalytic conditions with 12 mol% of SmI2 and excess of Mg or Mg/Hg in the presence of TMSiCl in THF. OH-functionalized PPXs were obtained with moderate yields polymer and Mn of up to 16 000 g/mol.