| The spectroscopic characterizations of transition metal containing compounds play important role in various practical applications such as astrophysics,high tempera-ture chemistry and surface science.In addition,the study of structure and bonding properties of transition metal containing compounds provides important data for the understanding of fundamental chemical reaction processes.This thesis presents the ex-perimental studies on the laser-induced fluorescence(LIF)excitation spectra of the three 3d transition-metal Co and Ni hydride and oxide.The CoO,CoH and NiH molecules were produced by reaction of sputtered metal atoms with small molecule gas under su-personic jet cooled condition.Every band observed has been rotationally analyzed.The electronic structure and chemical bonding of each molecule was discussed.The main results are summarized as follows:â—The laser-induced fluorescence excitation spectrum of jet-cooled CoO molecules has been reinvestigated in the range of 540-725nm.A to-tal of 95 bands have been observed,among them,59 bands were reported for the first time.Three vibrational band progressions were assigned as C4â–³7/2-X4â–³7/2,E4â–³7/2-X4â–³7/2and F4â–³7/2-X4â–³7/2,with (0,0)band at 13950cm-1,15241cm-1and 15650cm-1,respectively. AnΩ=9/2-7/2 transition system with(0,0)band at 14609cm-1was assigned as D4Φ7/2-Xâ–³7/2.NineteenΩ'=5/2-Ω"=7/2 vertical transi-tion bands have been classified into three transitions with(0,0)band at 13998,14202 and 15858 cm-1,designated as[13.99]Ω'=5/2-X4â–³7/2, [14.20]Ω'=5/2-X4â–³7/2and[15.85]Ω'=5/2-X4â–³7/2,respectively. The possible electronic configurations of the three upper states have been discussed.â—The laser induced fluorescence excitation spectrum of CoH molecule has been investigated in the range of 530-730nm.A total of 9 bands have been observed,and three new bands were reported.Lifetime measurements for the upper states of all the bands were carried out under the collision-free condition.Accurate rotational constants of every band have been obtained by least-square fitting.FiveΩ'=4-Ω"=4 strong bands were designated as A' 3Φ4-X 3Φ4(v'=1-5-v"=0) transition.Band at 16002 cm-1was proved to beΩ'=3-Ω"=4 transi-tion.The three new bands at 14073cm-1,15402cm-1and 17678 cm-1 were proved to beΩ'=3-Ω"=4 transition,designated as D 3â–³3-X 3Φ4(v'=1,2,4-v"=0)electronic transition.Accurate rotational con-stants of these bands have been obtained.The spectroscopic constants are compared with the isovalent CoF molecule and Co+ ion.â—The laser-induced fluorescence excitation spectra of supersonic jet-cooled NiH have been recorded in the range of 15000-22000 cm-1,in which the NiH molecules were produced by the reaction of sputtered nickel atoms with methanol.Thirty NiH bands were rotationally an-alyzed and classified into six electronic transitions,A,B,D,E,F and G state from the X2â–³5/2(v"=0)ground state.The molecular pa-rameter such as vibrational frequency,unharmonic constant,rota-tional constant and equilibrium length of these states have been deter-mined.The 19000-22000 cm-1spectrum of NiH was reported for the first time.In addition,a few weak bands were also observed,and the lifetimes of the upper states involved in these bands were measured.
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