Modification of naphthalenic unit in BBL main chain

• A brominated poly(benzimidazobenzophenanthroline), BBL has been synthesized.
• BBL has been substituted with aliphatic side chains.
• Polymers are soluble in organic solvents.

One of the monomers, 1,4,5,8-naphthalenetetracarboxylic acid used in the preparation of poly(benzimidazobenzophenanthroline) (BBL) has been successfully modified and used in a polycondensation reaction to yield derivatized BBL. The monomer has been mono- and dibrominated and the monobrominated product has been used as such as a monomer. Brominated NTCA is a versatile precursor for further modification, and as a proof of concept the bromine has been replaced with cyano and azide function and the azide has been further used in a click-reaction to introduce a side chain. The bromine was also directly replaced with 2-ethyl-1-hexylamine. The modification of the aromatic unit changes the band gap of the polymer as observed in the UV–vis-spectra. Introduction of bulky side chains make the polymers slightly soluble in NMP and DMSO and the solubility was found to increase with temperature.

Figure optionsDownload as PowerPoint slide