1149-16-2Relevant articles and documents
Experimental and theoretical approaches to redox innocence of ligands in uranyl complexes: What is formal oxidation state of uranium in reductant of uranyl(VI)?
Takao, Koichiro,Tsushima, Satoru,Ogura, Toshinari,Tsubomura, Taro,Ikeda, Yasuhisa
, p. 5772 - 5780 (2014)
Redox behavior of [UO2(gha)DMSO]-/UO 2(gha)DMSO couple (gha = glyoxal bis(2-hydroxanil)ate, DMSO = dimethyl sulfoxide) in DMSO solution was investigated by cyclic voltammetry and UV-vis-NIR spectroelectrochemical technique, as well as density functional theory (DFT) calculations. [UO2(gha)DMSO]- was found to be formed via one-electron reduction of UO2(gha)DMSO without any successive reactions. The observed absorption spectrum of [UO 2(gha)DMSO]-, however, has clearly different characteristics from those of uranyl(V) complexes reported so far. Detailed analysis of molecular orbitals and spin density of the redox couple showed that the gha2- ligand in UO2(gha)DMSO is reduced to gha ?3- to give [UO2(gha)DMSO]- and the formal oxidation state of U remains unchanged from +6. In contrast, the additional DFT calculations confirmed that the redox reaction certainly occurs at the U center in other uranyl(V/VI) redox couples we found previously. The noninnocence of the Schiff base ligand in the [UO2(gha)DMSO]-/UO 2(gha)DMSO redox couple is due to the lower energy level of LUMO in this ligand relative to those of U 5f orbitals. This is the first example of the noninnocent ligand system in the coordination chemistry of uranyl(VI).
Schiff bases-titanium (III) & (IV) complex compounds: Novel photocatalysts in Buchwald-Hartwig C–N cross-coupling reaction
Absalan, Yahya,Ghandi, Khashayar,Gholizadeh, Mostafa,Kovalchukova, Olga,Mahmoudi, Ghodrat,Sarvestani, Hossein Sabet,Shad, Nazanin Noroozi,Strashnov, Pavel
, (2021/05/21)
Nine novel Schiff bases were derived from salicylic aldehyde and oxalic aldehyde, isolated, and their molecular and spatial structure were explored by a set of experiments (IR, CNMR, HNMR, CHN, SEM, XRD) and theoretical simulation (DFT def2-TZVP). A high potential was predicted in metal cations chelating. The isolated organic species were applied as the ligands in the reaction of complex formation with titanium (III) chloride and (IV) bromide and 12 novel complexes were synthesized and studied experimentally and theoretically. Using the UV–vis spectroscopic titration, the solution stability of the complexes was indicated. Depending on the nature of the Schiff base ligand, their formation constants were calculated in the range of 6.84–17.32. Using the DFT def2-TZVP theoretical method together with the experimental spectroscopic data, the coordination types of the ligands were investigated, and the structure of the complexes was proposed. The photocatalytic ability of the isolated complexes was tested in the C-N cross-coupling reaction under sunlight. Complexes exhibited high visible-light photocatalytic activity for a wide range of aromatic and benzylic amines including electron-withdrawing and electron-donating groups from moderate to good yields ranging in 50–85 %. The use of an inexpensive, clean, and renewable energy source (visible light) is the superiority of the developed photocatalytic systems.
Reactions of α,N-Diarylnitrones with O-Methyl Diphenylphosphinothioate and Oxidations of N-Alkylidene-2-hydroxyanilines with Silver Oxide. Preparation of Benzoxazoles
Yoshifuji, Masaaki,Nagase, Rihei,Inamoto, Naoki
, p. 873 - 876 (2007/10/02)
Reactions of α,N-diarylnitrones in the presence of O-methyl diphenylphosphinothioate at 150 deg C gave 2-arylbenzoxazoles (3) in fairly good yields.Oxidation of N-alkylidene-2-hydroxyanilines with silver oxide afforded 2-alkenyl-, 2-alkyl-, or 2-arylbenzoxazoles (7 and 3) in good yields under mild reaction conditions (at room temperature).A plausible mechanism for formation of 3 and 7 has been discussed briefly.
