A study on tailor made ruthenium sulfoxide complexes: Synthesis, characterization and application

In this study, a dinucleating spacer incorporating two 2-aminopyridine units has been used to prepare seven novel dinuclear compounds. These molecules were characterized by elemental analyses, conductivity measurements, magnetic susceptibility, FT-IR, FAB-Mass, electronic, 1H and 13C{1H}NMR spectral studies. The complex [{trans,mer-RuCl2(DMSO)3}2(μ-5,5'-methylenebis(2-aminopyridine))].2DMSO, 2 was also characterized through 1H-1H COSY NMR. There are mainly three different formulations; [{cis,fac-RuCl2(SO)3}2(μ-MBAP)].2SO; [{trans,mer-RuCl2(SO)3}2(μ-MBAP)].2SO and [{trans-RuCl4(SO)}2(μ-MBAP)]2- [X]2+; where SO = DMSO / TMSO; MBAP = 5,5'-methylenebis(2-aminopyridine) and [X]+ = [(DMSO)2H]+, Na+ or [(TMSO)H]+. The coordination was found through cyclic nitrogen of pyridine ring in octahedral environment for both metal centers. The chemical behivour of [{cis,fac-RuCl2(DMSO)3}2(μ-5,5'-methylenebis(2-aminopyridine))].2DMSO, 1 and 2 in aqueous solution with respect to time was observed by conductivity measurements and UV-vis spectrophotometer. All complexes were found to possess prominent antibacterial activity against Escherichia coli in comparison to Chloramphenicol and Gatifloxacin

Metallo-antiviral aspirants: Answer to the upcoming virus outbreak

In light of the current SARS-CoV-2 outbreak, about one million research papers (articles, reviews, communications, etc.) were published in the last one and a half years. It was also noticed that in the past few years; infectious diseases, mainly those of viral origin, burdened the public health systems worldwide. The current wave of the Covid-19 pandemic has unmasked critical demand for compounds that can be swiftly mobilized for the treatment of re-emerging or emerging viral infections. With the potential chemical and structural characteristics of organic motifs, the coordination compounds might be a promising and flexible option for drug development. Their therapeutic consequence may be tuned by varying metal nature and its oxidation number, ligands characteristics, and stereochemistry of the species formed. The emerging successes of cisplatin in cancer chemotherapy inspire researchers to make new efforts for studying metallodrugs as antivirals. Metal-based compounds have immense therapeutic potential in terms of structural diversity and possible mechanisms of action; therefore, they might offer an excellent opportunity to achieve new antivirals. This review is an attempt to summarize the current status of antiviral therapies against SARS-CoV-2 from the available literature sources, discuss the specific challenges and solutions in the development of metal-based antivirals, and also talk about the possibility to accelerate discovery efforts in this direction

Effect of coordination dissymmetry on the catalytic activity of manganese catalase mimics

International audienceTwo mixed-valence Mn(II)Mn(III) complexes, [Mn2L1(OAc)2(H2O)]BPh4·2.5H2O and [Mn2L2(OAc)2]·4H2O, obtained with unsymmetrical N4O2-hexadentate L1(2−) (H2L1 = 2-(N,N-bis(2-(pyridylmethyl)aminomethyl)-6-(N-(2-hydroxybenzyl)benzylaminomethyl)-4-methylphenol) and N4O3-heptadentate L2(3−) (NaH2L2 = 2-(N,N-bis(2-(pyridylmethyl)aminomethyl)-6-(N′-(2-hydroxybenzyl)(carboxymethyl)aminomethyl)-4-methylphenol sodium salt) ligands, have been prepared and characterized. Both complexes share a μ-phenolate-bis(μ-acetate)Mn(II)Mn(III) core and N3O3-coordination sphere around the Mn(II) ion, but differ in the donor groups surrounding Mn(III) (NO4(solvent) and NO5). In non-protic solvents, these two complexes are able to disproportionate at least 3600 equiv. of H2O2 without significant decomposition, with first-order dependence on catalyst and saturation kinetics on [H2O2]. Spectroscopic monitoring of the reaction mixtures revealed the two complexes disproportionate H2O2 employing a different redox cycle, with retention of dinuclearity. The higher catalytic efficiency of [Mn2L2(OAc)2] was rationalized in terms of the larger labilizing effect of the heptadentate ligand that favors the acetate-shift and the replacement of the non-coordinating benzyl arm of L1 by a carboxylate arm in L2 which facilitates the formation of the catalyst-H2O2 adduct, placing [Mn2L2(OAc)2] as the most efficient among the phenolate-bridged diMn catalysts based on the kcat/KM criterion

Experiences during Synthesis of a Dinucleating Spacer Incorporating 2-Chloropyridine Units Through Sandmayer Reaction

A bimetallic cuprous complex was accidentally reported, during synthesis of a dinucleating spacer incorporating two 2-chloropyridine units through Sandmayer reaction. The product was characterized by elemental analysis, FAB-Mass, FT-IR, UV, magnetic susceptibility and 1H-NMR spectroscopic method. A possible mechanism is also proposed