Publications by authors named "Sayani Maity"
A nitrosyl complex of Mn-porphyrinate, 1 has been synthesized and characterized. It was found to donate a nitroxyl anion (NO) to suitable acceptors in dichloromethane solution in the presence of visible light. The evolution of NO and the characteristic reaction with PPh in the presence of H confirms the NO/HNO donation.
View Article and Find Full Text PDFArticle Synopsis
- A nitrosyl complex of Co(II)-porphyrinate, [CoII(TTMPP2-)(NO)], has been synthesized and characterized, showing a {Co(NO)}8 configuration.* -
- When this complex is mixed with hydrogen peroxide in a specific solvent at low temperature, it transforms into a nitrite complex, [CoIII(TTMPP2-)(NO2-)].* -
- Spectroscopic studies suggest the involvement of a Co(III)-peroxynitrite intermediate and the formation of a Co(IV=O) species, resulting in a Co(III)-porphyrin radical complex during this reaction.*
A Co(II) complex, [Co(L)(HO)](ClO), 1, having a bidentate ligand L [L = bis(3,5-dimethylpyrazolyl)methane] has been synthesized. Complex 1 in acetonitrile solution at -40 °C, in the presence of HO and NEt, afforded the corresponding Co(III)-peroxo species, [Co(L)(O)], as the transient intermediate 1a. Thermal instability precluded its isolation and further characterization.
View Article and Find Full Text PDFArticle Synopsis
- Nitroxyl (HNO) and its one-electron-reduced form, nitroxide (NO anion), offer unique pharmacological benefits over nitric oxide (NO), but HNO's role in chemical biology is less explored.
- Current HNO donors like Angeli's salt and Piloty's acid are limited in their applications.
- A new cobalt nitrosyl complex has been developed that can release HNO/NO in the presence of certain ligands, confirmed through gas chromatography-mass spectroscopy and reactions with known HNO/NO acceptors.
A five-coordinated {Mn(NO)} complex of Mn(II)-porphyrinate, [Mn(TMPP)(NO)], 1 {TMPPH = 5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin}, upon reaction with two equivalents of superoxide (O) in THF at -40 °C results in the corresponding Mn-OH complex [Mn(TMPP)(OH)], 2, the formation of a putative Mn-peroxynitrite intermediate. Spectral studies and chemical analysis suggest that one equivalent of superoxide ion is consumed to oxidize the metal center of complex 1 leading to [Mn(TMPP)(NO)], while the subsequent equivalent reacts with [Mn(TMPP)(NO)] to form the corresponding peroxynitrite intermediate. UV-visible and X-band EPR spectroscopic studies suggest the involvement of a Mn-oxo species in the reaction, which forms through the O-O bond cleavage of the peroxynitrite moiety with concomitant release of NO.
View Article and Find Full Text PDF