Characterization and side chain manipulation in violet-blue poly-[(9,9-dialkylfluoren-2,7-diyl)-alt-co-(benzen-1,4-diyl)] backbones

In this work, conditions of Suzuki condensation and polymer modification of polymers of benzene and fluorene units have been studied. A new polymer was prepared with statistical equimolecular amounts of two 2,7-dibromo-9,9-bis(6'-susbtituted-hexyl)fluorene as starting monomers. The C9 position of the poly [9,9-bis(6'-bromohexylfluoren-2,7-diyl)-alt-co-(benzen-1,4-diyl)] has been substituted yielding poly[9,9-bis(6'-cyanohexylfluoren-2,7-diyl)-alt-co-(benzen-1,4-diyl)] with a high degree of conversion. All polymers were completely soluble in THF and chloroform and were characterized by NMR, FTIR, and elemental analysis. Molecular weights measured by gel permeation chromatography coupled with light scattering detector results in polydispersity values between 3.3 and 1.2. Their glass transitions temperature were over 90 and 99 degrees C by DSC. Comparative studies of optical properties in solution and solid state show similar values indicating that the remote substitution of functional group maintains the spectroscopic characteristics of the backbone. Cyclic voltammetry studies and preliminary results in bias potentials of electroluminiscent devices reveal that these polymers may be promising candidates to be used as hole and electron transporting materials.