ABSTRACT
A sulfur monoxide complex of platinum fluoride in the form of PtF2(η1-SO) was generated via the isomerization of a molecular complex Pt(SOF2) in cryogenic matrixes under UV-vis irradiation. The infrared absorptions observed at 1205.4, 619.8 and 594.9 cm-1 are assigned to the S-O, antisymmetric and symmetric F-Pt-F stretching vibrations of the PtF2(η1-SO) complex, which possesses nonplanar Cs symmetry with a singlet ground state according to density functional theory calculations. The experimental vibrational frequency and computed distance (1.449 Å) of the SO ligand indicate that the SO ligand features a positively charged character, which is further confirmed by natural bond orbital analysis and Mayer bond order. Such character is completely different from that for early transition metal-SO complexes and dioxygen complexes of platinum. Formation of the PtF2(η1-SO) complex was found to occur via the consecutive transfer of the two fluorine atoms from SOF2 to Pt in the sulfur bound Pt(SOF2) complex, which involves a series of intermediates on the basis of the mechanism study at the B3LYP level. Although the whole process is hindered by the large energy barrier encountered during the transfer of the first fluorine atom, UV-vis irradiation can provide sufficient energy to surmount this barrier and facilitates the formation of the nonplanar PtF2(η1-SO) complex stabilized in matrix.
ABSTRACT
Anatase TiO(2) mesoporous structures with high specific surface areas are of special significance in various applications. In this work, hierarchical anatase TiO(2) materials with flowerlike morphologies have been prepared via a one-step template-free hydrothermal method, by using titanocene dichloride as precursor and EDA as chelating agent in aqueous solution. Particularly, the hierarchical structures are assembled from very thin TiO(2) nanosheets, which are composed of numerous highly crystallized anatase nanocrystals. In addition, the assembled materials own relatively large specific surface areas of 170 m(2)/g, and uniform mesopores of 7 nm. We further demonstrate that the hierarchical TiO(2) materials show very good photocatalytic performance when applied in photodegradation of methylene blue, which should be related to the unique features of hierarchical structures, large specific surface areas and high crystallization degree of the obtained TiO(2) materials. With these features, the hierarchical TiO(2) may find more potential applications in the fields such as dye-sensitized solar cells and lithium ion batteries.
