Insights into the spectral, thermal and morphological effects of co-oligomerization of pyrrole with luminol: A comparative experimental and computational study

Abstract The present study reports for the first time, synthesis of co-oligomers of pyrrole with luminol via chemical polymerization technique. Co-oligomerization was investigated by 1H NMR, FTIR spectroscopic studies showed that oligomerization occurred after the monomer feed ratio which formed blocks, the later carrying the same monomer ratio as the feed ratio. By applying DFT method, optimized geometries of the oligomers and co-oligomers, distribution of HOMO and LUMO orbitals, Mulliken charge were computed. The same theory with the above basis set was used to compute Fukui’s indices: f+, f− and fo to find out nucleophilic, electrophilic, and free radical points of attack on luminol and pyrrole monomers as well as dimers. Thermal degradation of co-oligomers was explored by TGA/DTG methods which revealed prominent degradation peak of luminol moiety. Since the co-oligomer is unexplored, modification of the molecular structure as well as opto-electronic properties could be attempted for designing bioimaging agents.