Study On The Spectroscopy Of Diatomic Transition Metal Containing Boride And Sulfur

This thesis presents the experimental studies on the laser-induced fluorescence (LIF) spectra of the three 3d transition-metal Co and Ni Sulfur and Boride. The NiB, CoS and NiS molecules were produced by reaction of sputtered metal atoms with small molecule gas under supersonic jet cooled condition. The electronic structure and chemical bonding of each molecule was discussed.The main results are summarized as follows:【1】The laser-induced fluorescence excitation spectra of jet-cooled NiB radical have been recorded in the energy range of19000-22100cm-1. Eleven bands have been assigned to the [20.77]2Π-X2Σ+transition system for the first time. The dispersed fluorescence spectra related to most of these bands have been investigated, vibrationally excited levels of the ground electronic state, with v″up to 6, have been observed. In addition, the lifetimes for almost all the observed bands have also been measured.【2】The Laser-induced fluorescence excitation spectra of jet-cooled CoS molecules have been recorded in the energy range of 15200-22600cm-1. Eight transition progressions have been assigned, there are five transition progressions assigned from the ground state in the energy range of 15200-19100cm-1, and three transition progressions assigned from the A state in the energy of 20100-22600cm-1. Identifiy eight new excited states for the first time and every excited state have been discussed. The dispersed fluorescence spectra related to most of these bands have been investigated, vibrationally excited levels of the ground electronic state and the A state have been observed. In addition, the lifetimes for almost all the observed bands have also been measured.【3】The laser-induced fluorescence excitation spectrum of jet-cooled NiS molecules have been recorded in the energy range of 15500-17200 cm-1. Fifteen bands have been assigned as three transition progressions:[15.65]3Π1[(ν′=0-4)-X3Σ0-(ν″=0), [15.69]3Σ0-(ν′= 0-4)-X3Σ0-(ν″=0), and [15.81]3Π1(ν′= 0-4)-X3Σ0-(ν″=0). Spectroscopic constants for the three newly identified electronically excited states have been determined for the first time. The dispersed fluorescence spectra related to most of these bands have been investigated, vibrationally excited levels of the ground electronic state, with v″up to 6, have been observed. In addition, the lifetimes for almost all the observed bands have also been measured.