SPECTROSCOPIC INVESTIGATION OF TRANSITION METAL COMPLEXES BY USE OF

ABSORPTION SPECTROSCOPY AND MULTIPHOTON IONIZATION

Lee, Sang Chun

Abstract

Spectroscopic investigation of various transition metal complexes was made by use of absorption spectroscopy and multiphoton ionization. Low temperature absorption spectra of Re⁴⁺ ion in distorted substitutional sites in (NR₄)₂SnCl₆ (R = CH₃, C₂H₅, and C₃H₇) hosts have been measured. The effects of reduced host symmetry have been observed such as increasing origin intensity, origin shift, different vibronic pattern. In addition, several new transitions located at above 16,000 cm^-1 have been found. The experimental results and calculational efforts on the newly observed "extra" bands of Re⁴⁺ in the (NR₄)₂SnCl₆ host crystals indicated that these transitions can not be fit very well. Ligand field theory might be limited to explain these "extra" transitional bands.

The next part of this research involved the MPI of various transition metal complexes in a pulsed supersonic jet expansion. Several instrumental modifications have been made. The multiphoton dissociation and ionization have been observed in Ni(CO)₄, nickelocene, and cobalt complexes, which gave us valuable information such as dissociation dynamics and intra molecular energy transfer. Finally, molecular MPI spectra of WF₆ have been measured. Clear assignments on molecular MPI bands of WF₆ could not be made at present status.