Theoretical Studies On Cyclometalated Platinum Complexes With β-Diketonate Ancillary Ligands And Triphenylene Derivatives

The properties of cyclometalated platinum complexes with longβ-diketonate ancillary ligand chains have been investigated using B3LYP method of DFTi(全称),including their structures, electronic absorption spectra and second-order nonlinear optical propertied.. It was found that a large conjugated system was formed by Pt atom, benzene, pyridine andβ-diketonate ancillary ligands, which made the electronic transition from the ground state to the first excited state (π→π* and n→π*) with a MLCT transition. The maximal absorption wavelength in the electronic transition located at around 406 nm, belonging to near UV. The length ofβ-diketonate ancillary alkyl had little influence on the structure and electronic spectra, which was in good agreement with experimental results. At the same time, the cyclometalated platinum complexes with longβ-diketonate ancillary ligand chain molecules displayed good nonlinear optical properties.The results of our study also showed that the electronic transition from the ground state to the first excited state came from the mixed transition of LLCT and MLCT. These complexes displayed good nonlinear optical properties. Theπ-π* transfer between the left ligands mainly induced the second-order nonlinear optical properties. However, the third-order nonlinear optical property was main determind by the charge transfer with d-π* character from metal Pt atom toβ-Diketonate Ancillary Ligands. The transition between the left ligands also played an important role on the third-order nonlinear optical property. The charge transport properties of the triphenylene derivatives, which had alkynyl in different peripheral chains, have been carried out at the level of B3LYP/6-31G** using DFT method. The results presented that all the title compounds were benefit to increasing the charge transport, but different peripheral chains had different effects on the charge transport. It was good to increase the transport of positive charge when introduced an amide (-CO-NH-) group to the discotic ring triphenylene directly. And the introduction of ester in peripheral chains, and chiral centers at the interval-group could support the positive and negative charge transports, but it would make the negative charge transport easier. The charge transport properties of monosubstituted on triphenylene were better than that of disubstituted and trisubstituted obviously.The charge transport properties of triphenylene discogens with a phenylpropionyloxy or 3-phenylpropenoyloxy side chain have been studied at B3LYP/6-31G** level as well. The results showed that three triphenylene derivatives had high charge mobility. Title compounds had better electronic mobility than that of the triphenylene. The triphenylenes containing 3-phenylpropenoyloxy had better hole mobility and smaller electronic mobility than those of triphenylenes with phenylpropionyloxy. For the triphenylene discogens with a phenylpropionyloxy, the longer the alklbxy chains, the better the positive charge transfer rate, but the smaller the negative charge transfer rate.