The matrix isolation infrared spectroscopic and quantum chemical calculation results indicate that vanadium oxides, VO2 and VO4, coordinate noble gas atoms in forming noble gas complexes. The results showed that VO2 coordinates two Ar or Xe atoms and that VO4 coordinates one Ar or Xe atom in solid noble gas matrixes. Hence, the VO2 and VO4 molecules trapped in solid noble gas matrixes should be regarded as the VO2(Ng)2 and VO4(Ng) (Ng = Ar or Xe) complexes. The total V-Ng binding energies were predicted to be 12.8, 18.2, 5.0, and 7.3 kcal/mol, respectively, for the VO2(Ar)2, VO2(Xe)2, VO4(Ar), and VO4(Xe) complexes at the CCSD(T)//B3LYP level of theory.

The reactions of group V metal dioxide molecules with dihydrogen have been studied by matrix isolation infrared spectroscopy. The ground state VO(2) molecule is able to cleave dihydrogen heterolytically and spontaneously in forming the HVO(OH) molecule in solid argon. In contrast, the reaction of VO(2) with dideuterium to form DVO(OD) proceeds only under UV-visible excitation via a weakly bound VO(2)(η(2)-D(2)) complex. Theoretical calculations predict that the dihydrogen cleavage process is thermodynamically exothermic with a small barrier. The niobium and tantalum dioxide molecules react with dihydrogen to give primarily the side-on bonded metal dioxide bis-dihydrogen complexes, NbO(2)(η(2)-H(2))(2) and TaO(2)(η(2)-H(2))(2), which are further transferred to the HNbO(OH) and HTaO(OH) molecules via photoisomerization in combination with H(2) elimination under UV-visible light excitation.

The resonance Raman spectra were obtained for both 2-thiopyridone (2TP) and its proton-transfer tautomer 2-mercaptopyridine (2MP) in water solution. Density functional theory (DFT) calculations were carried out to help elucidate their ultraviolet electronic transitions and vibrational assignments of the resonance Raman spectra associated with their B-band absorptions. The nanosecond time-resolved resonance Raman spectroscopic experiment was carried out to further confirm the assignment that the transient species was the ground state 2MP. The different short-time structural dynamics were examined for both 2TP and 2MP in terms of their resonance Raman intensity patterns. The transition barriers between 2TP and 2MP for S(0), T(1), and S(1) states are determined by using (U)B3LYP-TD and CASSCF level of theory computations, respectively. The excited state proton transfer (ESPT) reaction mechanism is proposed and briefly discussed.

The matrix isolation infrared spectroscopic and quantum chemical calculation results indicate that late transition metal monoxides CrO through NiO coordinate one noble gas atom in forming the NgMO complexes (Ng = Ar, Kr, Xe; M = Cr, Mn, Fe, Co, Ni) in solid noble gas matrixes. Hence, the late transition metal monoxides previously characterized in solid noble gas matrixes should be regarded as the NgMO complexes, which were predicted to be linear. The M-Ng bond distances decrease, while the M-Ng binding energies increase from NgCrO to NgNiO. In contrast, the early transition metal monoxides, ScO, TiO, and VO, are not able to form similar noble gas atom complexes.

Scandium monoxide-dinitrogen complexes-OSc(N2), OScNN, and OScNN+-have been prepared by the reactions of laser-evaporated scandium monoxide with N2 or scandium atoms with N2O in solid argon. The ground-state scandium monoxide molecule reacted with N2 to form the side-bonded OSc(N2) complex spontaneously on annealing. This complex rearranged to the end-on bonded OScNN complex upon UV irradiation. Both the OSc(N2) and OScNN complexes in solid argon can be assigned to have 2A' ' electronic ground state with Cs symmetry arising from the 2Delta first excited-state ScO. The neutral complexes can also be photoionized to the OScNN+ cation complex upon UV irradiation.

The combination of matrix isolation infrared spectroscopic and density functional calculation results provides strong evidence that the transition metal monoxide cation, ScO+, coordinates five noble gas atoms in forming the [ScO(Ng)5]+ (Ng = Ar, Kr, or Xe) complexes in noble gas matrixes.

The combination of matrix isolation infrared spectroscopic and quantum chemical calculation results provide strong evidence that scandium and yttrium monoxide cations, ScO+ and YO+, coordinate multiple noble gas atoms in forming noble gas complexes. The results showed that ScO+ coordinates five Ar, Kr, or Xe atoms, and YO+ coordinates six Ar or Kr and five Xe atoms in solid noble gas matrixes. Hence, the ScO+ and YO+ cations trapped in solid noble gas matrixes should be regarded as the [ScO(Ng)5]+ (Ng = Ar, Kr, or Xe), [YO(Ng)6]+ (Ng = Ar or Kr) or [YO(Xe)5]+ complexes. Experiments with dilute krypton or xenon in argon or krypton in xenon produced new IR bands, which are due to the stepwise formation of the [ScO(Ar)(5-n)(Kr)n]+, [ScO(Kr)(5-n)(Xe)n]+ (n = 1-5), [YO(Ar)(6-n)(Kr)n]+ (n = 1-6), and [YO(Ar)(6-n)(Xe)n]+ (n = 1-4) complexes.

Laser-evaporated chromium atoms are shown to insert into dioxygen to form CrO 2 in solid argon. Annealing allows diffusion and reactions to form (eta (2)-O 2) 2CrO 2, which is characterized as [(O 2 (-)) 2(CrO 2) (2+)], a side-on bonded disuperoxo-chromium dioxide complex. The (eta (2)-O 2) 2CrO 2 complex further reacts with xenon atom doped in solid argon to give (eta (1)-OO)(eta (2)-O 2)CrO 2(Xe), which can be regarded as an O 2 molecule weakly interacting with [(O 2) (2-)(CrO 2) (2+)Xe], a side-on bonded peroxo-chromium dioxide-xenon complex. The results indicate surprisingly that xenon atom induces a disproportionation reaction from superoxo to peroxo and dioxygen complex.