Molecular oxofluorides OMFn of nickel, palladium and platinum: oxyl radicals with moderate ligand field inversion

High-valent late transition metal oxo compounds attracted attention because of their peculiar metal–oxygen bond. Their oxo ligands exhibit an electrophilic and distinct radical oxyl (O˙−) rather than the more common nucleophilic (O2−) character.

Comparison of two MnIVMnIV-bis-μ-oxo complexes {[MnIV(N4(6-Me-DPEN))]2(μ-O)2}2+ and {[MnIV(N4(6-Me-DPPN))]2(μ-O)2}2+

The addition of tert-butyl hydroperoxide ( t BuOOH) to two structurally related MnII complexes containing N,N-bis(6-methyl-2-pyridylmethyl)ethane-1,2-diamine (6-Me-DPEN) and N,N-bis(6-methyl-2-pyridylmethyl)propane-1,2-diamine (6-Me-DPPN) results in the formation of high-valent bis-oxo complexes, namely di-μ-oxido-bis{[N,N-bis(6-methyl-2-pyridylmethyl)ethane-1,2-diamine]manganese(II)}(Mn—Mn) bis(tetraphenylborate) dihydrate, [Mn(C16H22N4)2O2](C24H20B)2·2H2O or {[MnIV(N4(6-Me-DPEN))]2(μ-O)2}(2BPh4)(2H2O) (1) and di-μ-oxido-bis{[N,N-bis(6-methyl-2-pyridylmethyl)propane-1,3-diamine]manganese(II)}(Mn—Mn) bis(tetraphenylborate) diethyl ether disolvate, [Mn(C17H24N4)2O2](C24H20B)2·2C4H10O or {[MnIV(N4(6-MeDPPN))]2(μ-O)2}(2BPh4)(2Et2O) (2). Complexes 1 and 2 both contain the `diamond core' motif found previously in a number of iron, copper, and manganese high-valent bis-oxo compounds. The flexibility in the propyl linker in the ligand scaffold of 2, as compared to that of the ethyl linker in 1, results in more elongated Mn—N bonds, as one would expect. The Mn—Mn distances and Mn—O bond lengths support an MnIV oxidation state assignment for the Mn ions in both 1 and 2. The angles around the Mn centers are consistent with the local pseudo-octahedral geometry.

Synthesis and Characterization of Bismuth Oxo Compounds Supported on TiO2 Photocatalysts for Waste Water Treatment

Azo dyes are usually used in textile industry. However, they can cause water contamination, lead to water pollution, damage to aquatic lives and degenerate scenery due to their toxicity. These problems can be overcome by photocatalytic process in which the azo dyes are converted to CO2 and water. This research concentrates on effect of Bi2O3, BiOBr and BiOI contents on titanium dioxide substance (TiO2) for the photocatalytic process. In the study, photocatalysts were synthesized by sol-gel and wetness impregnation methods. They were studied in surface area by BET technique, chemical composition by FT-IR spectroscopy and optical properties by UV-DRS technique. Increase in bismuth content on TiO2 results in decreasing surface area. In FT-IR spectra, Ti-O-Ti stretching bands at 400-800 cm-1 were detected. The band gap energy of these photocatalysts is decreased when bismuth was doped. Since efficiency of CO2 and water conversion of the photocatalysts can be determined indirectly via determinaiton of decreasing Methyl Orange (MO) concentration, the lowest MO concentration was observed in the 4%Bi2O3T photocatalyst after 16 hours when compared to the other photocatalyst samples and Degussa P25. In other words, this photocatalyst efficiently converts the azo dyes to CO2 and water.