| dc.description.abstract | Abstract
This thesis reports the synthesis of a few nonplanar conjugated molecules as organic light-emitting materials. We first synthesized diaminostilbenes 1-A, 1-B, and 1-C to ensure that these fluorophores would have high fluorescence quantum yields in organic solvents. We then introduce the bulky triptycene group to these diaminostilbenes to form the compound series II (2-A, 2-B, and 2-C). The fluorescence maxima in dichloromethane, decomposition temperatures, glass transition temperatures, the HOMO energies, and the LUMO energies of compounds 2 are in the range of 429-441 nm, 325-375 oC, 80-120 oC, 5.00-5.17 eV, and 1.98-2.22 eV, respectively. Among the three compounds, 2-C has the best physical properties as a blue emitter, and a reasonable OLED device structure for such a purpose would be ITO/NPB/2-C/TPBI/Mg:Ag, where NPB and TPBI are hole and electron transporting materials, respectively. We also have designed a series of pentiptycene-ethynylene oligomers (compound series III) on the basis of the known feature that the nonplanar pentiptycene-incorporated poly(phenylene ethynylene)s can maintain a high fluorescence quantum yields in the solid state. However, the bulky pentiptycene group complicates the synthesis, which requires a subtle control of the reaction conditions, including the amount of butyl lithium, reaction time and temperature, and the choice of reducing reagents. We have currently synthesized 3-A and 3-B, and will find the optimum conditions to prepare oligomers 3-C and 3-D. | en_US |