synthesis and characterization of novel 4-cynanophenyl-functionalized n4,n4,n4′,n4′-teraphenylbenzidine (tpb) as hole transporting molecular materials

In this study, a new cyanophenyl-functionalized N4,N4,N4′,N4′-tetraphenylbenzidine (TPB) containing employable hole-transporting components has been synthesized with Pd-catalyzed Suzuki-Miyaura cross coupling reaction. N4,N4,N4′,N4′tetrakis-(4′-cynobiphenyl-4-yl)-biphenyl-4,4′-diamine (TPB-CN)  was well characterized by 1H NMR, 13C NMR and CHN elemental analysis. The compound TPB-CN exhibited good thermal stability and luminescence properties. Time Dependent Density Functional Theory (TDDFT) computation was carried out to investigate the structural parameters and to understand the photophysical properties of the novel TPB-CN compound. The experimental and theoretical calculations performed to calculate absorption maxima in DCM by UV-Vis and TD-B3LYP/6-31g(d,p) were compared with each other. To identify crystal structure and to determine optical band gap of TPB-CN compound, its film form, which was coated on the glass substrate by spin coating, was used. The band gap of TPB-CN compound both in film and in solution was determined from the optical absorption measurements.