Tetracarboxylic bisimide–lactam ring contraction: a route to lactamimide-containing polymers

Abstract First lactamimide monomers were synthesised by the bisimide–lactam ring contraction and polymerised by the high-temperature transesterification in the melt to give lactamimide-containing polymers. The polymers were amorphous with good film-forming properties, soluble in common organic solvents, and showed from low to medium molecular weight. Lactamimide-containing polymers bearing aliphatic spacers showed strong fluorescence with large Stokes shift (140–150 nm) peaking at 580–585 nm while those with phenyl groups on nitrogen atoms presented very weak fluorescence probably resulting from loose-bolt quenching, peaking at 610–615 nm. The polymers showed third-order non-linear optical susceptibility in the range of 10 −10 –10 −11  e.s.u.