Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (05): 1089-1094.doi: 10.3866/PKU.WHXB20110505

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

Structures and Spectroscopic Properties of [Ru(iph)(L)2]2+ (L=cpy, mpy, npy) Complexes Containing Tetradentate Ligands

ZHANG Jian-Po1, JIN Li1, ZHANG Hong-Xing2   

  1. 1. School of Chemical and Pharmaceutical Engineering, Jilin Institute of Chemical Technology, Jilin 132022, Jinlin Province, P. R. China;
    2. State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Changchun 130023, P. R. China
  • Received:2011-01-03 Revised:2011-02-10 Published:2011-04-28
  • Contact: JIN Li E-mail:canoe8013@126.com
  • Supported by:

    The project was supported by the Foundation of State Key Laboratory of Theoretical and Computational Chemistry, China.

Abstract:

The geometries of ground and excited states of a series of ruthenium complexes [Ru(iph)(L)2]2+(L=cpy (1), mpy (2), npy (3); iph=2,9-di(1-methyl-2-imidazole)-1,10-phenanthroline, cpy=4-cyano pyridine, mpy=4-methyl pyridine, npy=4-N-methyl pyridine) were optimized by the Becke′s three-parameter functional and the Lee-Yang-Parr (B3LYP) functional and unrestricted B3LYP methods, respectively. Time- dependent density functional theory (TD-DFT) method at the B3LYP level together with the polarized continuum model (PCM) were used to obtain their absorption and phosphorescent emission spectra in acetone media based on their optimized ground and excited-state geometries. The results revealed that the optimized structural parameters agreed well with the corresponding experimental results. The highest occupied molecular orbitals were localized mainly on the d orbital of the metal and the π orbital of the iph ligand for 1 and 2, and the npy ligand for 3, while the lowest unoccupied molecular orbitals were mainly composed of π* orbital of the iph ligand. Therefore, the lowest-lying absorptions and emissions were assigned to the metal to ligand charge transfer (MLCT)/intra-ligand charge transfer (ILCT) transition for 1 and 2, and the ligand to ligand charge transfer (LLCT) transition for 3. The lowest-lying absorptions are at 509 nm (1), 527 nm (2), and 563 nm (3) and the phosphorescence emissions at 683 nm (1), 852 nm (2), and 757 nm (3). The calculation results show that the absorption and emission transition characteristics and the phosphorescence color can be changed by altering the π electron-donating ability of the L ligand.

Key words: Tetradentate ligands Ru complexes, Excited state, Time-dependent density functional theory, Spectroscopic property, Charge transfer

MSC2000: 

  • O641