Research and Development

@article{Guidote2001,

title = {Synthesis, characterization and reactivity of a series of dinuclear copper complexes bearing the ligand bis[3-(2-hydroxybenzylideneamino)phenyl] sulfone and derivatives},

author = {Armando M. Guidote Jr. and Ken-ichi Ando and Kazunori Terada and Yasuhiko Kurusu and Hirotaka Nagao and Yoshiro Masuyama},

url = {https://www.sciencedirect.com/science/article/abs/pii/S0020169301005898},

doi = {10.1016/S0020-1693(01)00589-8},

year  = {2001},

date = {2001-11-15},

journal = {Inorganica Chimica Acta},

volume = {324},

pages = {203-211},

abstract = {The ligands bis[3-(X-2-hydroxybenzylideneamino)phenyl] sulfones (X=none: BHBAPS, X=3-tert-butyl: BH(t-Bu)BAPS and X=3,5-dichloro: BHCl2BAPS) were prepared. These, together with Cu(OAc)2 were used in the syntheses of the dinuclear copper complexes Cu2(BBAPS)(μ-OMe)2 (1), Cu2[B(t-Bu)BAPS] (μ-OH)2 (2), and Cu2[BCl2BAPS] (μ-OMe)2 (3). Complex 1 was crystallographically characterized. The structures of 2 and 3 are similar to 1 by comparison of IR, UV–Vis, FAB-MS and elemental analyses results. Complexes 1–3 (1 mol%) were used in the oxidation of 2,4- and 2,6-di-t-butylphenol (dtbp) at −50 °C with H2O2. The results show that (1) the coupling products are preferred when CH2Cl2 is used; and (2) the quinone yield increases when THF is utilized. In CH2Cl2 with 2,4-dtbp, the yield of the coupling product based on the complex amount, is in the order 2, 1, and 3 with yields of 6300, 4700 and 200%, respectively. Low temperature UV–Vis results of the reaction of 1 with H2O2 showed the growth of peaks at 390 and 580 nm indicative of a μ-η2:η2-peroxo or μ-η1:η1-hydroperoxo intermediate. At −50 °C, this spectrum does not change. But when warmed to 0 °C, a spectrum similar to the original spectrum was obtained. This probably indicates hydrogen radical abstractions of the peroxo intermediate from solvents, and if excess H2O2 is present, the peroxo intermediate may again be formed. This reusability of the complex explains the high yield using 1 and 2.



The ligands bis[3-(X-2-hydroxybenzylideneamino)phenyl] sulfones (X=none: BHBAPS, X=3-tert-butyl: BH(t-Bu)BAPS and X=3,5-dichloro: BHCl2BAPS) were prepared. These, together with Cu(OAc)2 were used in the syntheses of the dinuclear copper complexes Cu2(BBAPS)(μ-OMe)2 (1), Cu2[B(t-Bu)BAPS](μ-OH)2 (2), and Cu2[BCl2BAPS](μ-OMe)2 (3). Complex 1 was crystallographically characterized. The structures of 2 and 3 are similar to 1 by comparison of IR, UV–Vis, FAB-MS and elemental analyses results. Complexes 1–3 (1 mol%) were used in the oxidation of 2,4- and 2,6-di-t-butylphenol (dtbp) at −50 °C with H2O2.},

keywords = {catalysis, copper complex, dinuclear, oxidation, schiff base type ligand},

pubstate = {published},

tppubtype = {article}

}

@article{Guidote2001b,

title = {Syntheses and characterization of homodinuclear manganese and cobalt complexes bridged by a hemiacetal or by an acetato group in a μ-(η2:η1) bridging mode},

author = {Armando M. Guidote Jr. and Ken-ichi Ando and Yasuhiko Kurusu and Hirotaka Nagao and Yoshiro Masuyama},

url = {https://www.sciencedirect.com/science/article/abs/pii/S0020169301002948},

doi = {10.1016/S0020-1693(01)00294-8},

year  = {2001},

date = {2001-03-07},

journal = {Inorganica Chimica Acta},

volume = {314},

pages = {27-36},

abstract = {The complex [Mn2(BPMAPS)(μ-OAc)2(hemi)]PF6 (1), where hemi is the hemiacetal group, methoxy(2-pyridyl)methoxo, was prepared from bis[3-(2-pyridylmethyleneamino)phenyl] sulfone (BPMAPS), 2-pyridinecarbaldehyde, and manganese(II) acetate in methanol. The complexes Mn2(BPMAPS)(μ-OAc)2(μ-1,1-OAc)(η1-OAc) (2) and Co2(BPMAPS)(μ-OAc)2-[μ-(η2:η1)OAc](η1-OAc) (3) were prepared from manganese(II) acetate and cobalt(II) acetate, respectively, with BPMAPS in methanol. All three complexes were characterized by elemental analysis, FT-IR, MS, UV–Vis spectroscopy, and X-ray crystallography. The manganese ions of complex 1 are bridged by a hemiacetal through the oxygen atom of the alkoxo with the nitrogen atom of the pyridine group coordinating to one of the manganese atoms. The metal ions of complexes 2 and 3 are bridged by acetato groups in μ-1,1 or μ-η2:η1 modes, respectively.},

keywords = {cobalt complex, dinuclear, manganese complex, schiff base type ligand},

pubstate = {published},

tppubtype = {article}

}