title: Matrix isolation infrared spectroscopic and theoretical studies on the reactions of niobium and tantalum mono- and dioxides with methane.
abstract: The reactions of niobium and tantalum monoxides and dioxides with methane have been investigated using matrix isolation infrared spectroscopic and theoretical calculations. The niobium and tantalum oxide molecules were prepared by laser evaporation of Nb(2)O(5) and Ta(2)O(5) bulk targets. The niobium monoxide molecule interacted with methane to form the ONb(CH(4)) complex, which was predicted to have C(3)(v)() symmetry with the metal atom coordinated to three hydrogen atoms of the methane molecule. The ONb(CH(4)) complex rearranged to the CH(3)Nb(O)H isomer upon 300 nm < lambda < 580 nm irradiation. The analogous OTa(CH(4)) complex was not observed, but the CH(3)Ta(O)H molecule was produced upon UV irradiation. The niobium and tantalum dioxide molecules reacted with methane to form the O(2)Nb(CH(4)) and O(2)Ta(CH(4)) complexes with C(s)() symmetry, which underwent photochemical rearrangement to the CH(3)Nb(O)OH and CH(3)Ta(O)OH isomers upon ultraviolet irradiation.
authors.affiliation: Department of Chemistry and Laser Chemistry Institute, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai 200433, People's Republic of China.
authors.forename: Guanjun
authors.initials: G
authors.lastname: Wang
authors.forename: Sixue
authors.initials: S
authors.lastname: Lai
authors.forename: Mohua
authors.initials: M
authors.lastname: Chen
authors.forename: Mingfei
authors.initials: M
authors.lastname: Zhou
mesh_terms: D008697:Methane / Q000737:chemistry* / Q000528:radiation effects; D008956:Models, Chemical; D009556:Niobium / Q000737:chemistry* / Q000528:radiation effects; D010087:Oxides / Q000737:chemistry* / Q000528:radiation effects; D010777:Photochemistry; D011789:Quantum Theory; D012680:Sensitivity and Specificity; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013635:Tantalum / Q000737:chemistry* / Q000528:radiation effects; D014466:Ultraviolet Rays; D014732:Vibration
chemical_list: D010087:Oxides; D009556:Niobium; D013635:Tantalum; D008697:Methane