Font Size: a A A

Theoretical Study On Organic Electroluminescent Materials

Posted on:2007-03-09Degree:MasterType:Thesis
Country:ChinaCandidate:X B LiFull Text:PDF
GTID:2121360185980944Subject:Physical chemistry
Abstract/Summary:PDF Full Text Request
In this paper, five systems have been studied by quantum chemistry methods: (1) 1,3,4-oxadiazole derivatives and 1,2,4-triazole derivatives; (2) Zinc complex with 8-thiolquinoline anion and its derivatives; (3) phenol and 1-naphthol; (4) Mes2B[p-4,4'-biphenyl-Nph(1-naphthyl)]; (5) cyclometalated Pt(Ⅱ) complexes with N?C?N-coordinating dipyridylbenzene ligands.Firstly, By means of DFT B3LYP methods, the structures of two kinds of electron-transport materials in neutral, cationic and anionic states were optimized. The results suggest that the process of electronic transmission of 2,5-diphenyl-1,3,4-oxadiazole is mainly the N→O transferences, the process of electronic transmission of 3,4,5-triphenyl-1,2,4-triazole is mainly the N(double linkage)→N(single linkage) transferences and the transition from the triazole ring to the benzene ring connected with the N atom. The benzene ring was given the electron acceptor groups substitution in its third position, the electronic transmission performance enhancement, while given electron donor groups substitution, the electronic transmission performance reduces.Secondly, The structures of zinc complex with 8-thiolquinoline anion (Zn(tq)2) and its derivatives were optimized in the ground state using ab initio HF and B3LYP methods, and absorption spectra based on the above structures were obtained by the time-dependent density functional theory (TD-DFT) by the B3LYP method with the 6-31+G(d) basis set. At the same time, the molecular structure of the first singlet excited state for Zn(tq)2 and its derivatives was optimized by CIS/6-31G(d), with the EL peak could be obtained by the emission spectrum with TD-B3LYP/6-31G(d) method. The calculated results indicated that the luminescence originates from the electronic transition from the thiophenol ring to the pyridine ring. The calculated results of absorption spectrum and emission spectrum for zinc complex with 8-thiolquinoline anion and its derivatives have good agreement with the experimental data. All compounds are excellent electron-transporting materials, luminescence wave bands of which can be tuned by different metals and substituent on the ligand of 8-thiolquinoline anion.Thirdly, The molecular structures of the ground state and the first singlet excited state for C6H5OH2+, C6H5OH, C6H5O- , C10H7OH2+, C10H7OH and C10H7O- of the forms of phenol and 1-naphthol in acid and alkali solution were optimized by ab initio HF and configuration interaction with singlet excitations (CIS) method respectively.
Keywords/Search Tags:Time-dependent density functional theory, ionization potential, electron affinity, proton affinity, absorption spectrum, emission spectrum
PDF Full Text Request
Related items