A study on the excitations of ligand-to-metal charge transfer in complexes Cp2MCl2 (Cp=π-C5H5, M=Ti, Zr, Hf) by density functional theory

Xiaojing Wang, Lv Chen, Akira Endou, Momoji Kubo, Akira Miyamoto

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)

Abstract

The excitations of ligand-to-metal charge transfer in the UV-vis spectra of the complexes Cp2MCl2 (Cp=π-C5H5, M=Ti, Zr, Hf) were described with the time-dependent density functional theory and the differential self-consistent-field density functional theory (ΔSCF-DFT). The nature of the main spectral features was interpreted on the basis of the electronic structure of the complexes. The optimization of the molecular structure for Cp2MCl2 yielded consistent pseudotetrahedral geometries. With the transition from ground state to excited state, the electrons transferred from Cp ligands to the central metals M, accompanied by an increase in the binding length of M-Cl. This transfer process accounted for the first two absorption bands observed experimentally. The energies and oscillator strengths for the low-lying excitations depended strongly on the nature of the central metals. With varying the central metals from Ti, Zr, and to Hf, the energy gap increased between the sets of highest occupied molecular orbitals (HOMOs) and the sets of lowest unoccupied molecular orbitals (LUMOs). This increase was originated from an increment of energy for the LUMO sets that are mainly of d orbital of the metal and a relatively stable energy level of the HOMO sets that are mainly of p-orbital of Cp and Cl ligands. The excitation energies calculated by these methods showed a small difference, which can be well understood by a relativistic effect. The predicted level patterns of the lowest triplet excited states fit well the available phosphorescence data.

Original languageEnglish
Pages (from-to)156-165
Number of pages10
JournalJournal of Organometallic Chemistry
Volume678
Issue number1-2
DOIs
Publication statusPublished - 2003 Jul 15

Keywords

  • Density functional theory
  • Electronic spectrum
  • Excited state
  • Ligand-to-metal charge transfer
  • Organometallic complexes

ASJC Scopus subject areas

  • Biochemistry
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

Fingerprint Dive into the research topics of 'A study on the excitations of ligand-to-metal charge transfer in complexes Cp<sub>2</sub>MCl<sub>2</sub> (Cp=π-C<sub>5</sub>H<sub>5</sub>, M=Ti, Zr, Hf) by density functional theory'. Together they form a unique fingerprint.

Cite this