Carbon monoxide-releasing properties and DFT/TDDFT analysis of [Mn(CO) 3 (bpy)L]PF 6 type novel manganese complexes

A comprehensive survey of Mn(I) carbonyls as CO-releasing molecules reported over the last two decades

Over the last two decades, manganese(I) carbonyl complexes have been widely investigated as carbon monoxide releasing molecules (CORMs) to transfer small quantities of CO to biological targets to have beneficial impacts such as preventing ischemia reperfusion injury and reducing organ transplant rejection. Furthermore, these complexes exhibit beneficial anti-coagulative, anti-apoptotic, anti-inflammatory, and anti-proliferative properties. Owing to their highly controlled substitution chemistry and oxidative durability, Mn(I) carbonyl moieties were combined with a wide range of auxiliary ligands, including biomolecules. This review focused on tri- and tetracarbonyl Mn(I) complexes that were exposed to light, changed the redox status, or underwent thermal activation to release carbon monoxide. Kinetic parameters, stability in the dark, number of CO release equivalents, CO detection tools, and the nature of solvents used in the studies are reported and tabulated. An overview of all the previously published Mn(I) CORMs is specifically provided to define the method of action of these promising biologically active compounds and discuss their possible therapeutic applications in relation to their CO-releasing and biocompatibility characteristics.

A simple theoretical approach to converging of Myoglobin-Assay with different pH values

Many metal carbonyl complexes have been synthesized and analyzed as CO-releasing agents. As in many bioactivity assays, differences between in-vitro and in-vivo studies in Myoglobin Assay have been observed. Adjustment of in-vitro conditions to in-vivo conditions is one way to overcoming this problem. Changing the conditions of each in-vivo assay is not possible considering the available grant, material, and labor facilities. In-silico methods are suitable as they provide better in-vitro conditions before experimental procedures. A method which is easy to employ on a basic computer could be more suitable to observe the assay convergence. In this study, global reactivity descriptors were used as an approach to investigate pH differences in myoglobin assay. Global reactivity descriptors of the molecules were compared with myoglobin assay results at different pH values and molecular docking results performed with optimized molecules in different solvents. The following complexes were studied: [Mn(CO)3(bpy)(L)]PF6 (bpy: 2,2-bipyridyl, L: benzylbenzimidazole, 4-chlorobenzylbenzimidazole).

Synthesis, structures, DFT calculations, and catalytic application in the direct arylation of five-membered heteroarenes with aryl bromides of novel palladium-N-heterocyclic carbene PEPPSI-type complexes

A new series of Pd-catalysts was synthesized and fully characterized via spectroscopic methods and the Pd–NHC complexes were evaluated via the direct arylation process.

Mono- and bimetallic manganese-carbonyl complexes and clusters bearing imidazol(in)ium-2-dithiocarboxylate ligands

Five complexes with the generic formula fac-[MnBr(CO)₃(S₂C·NHC)] were obtained by reacting [MnBr(CO)₅] with a set of representative imidazol(in)ium-2-dithiocarboxylate zwitterions. These ligands are the adducts of N-heterocyclic carbenes (NHCs) and carbon disulfide. The mononuclear Mn(i) derivatives were coupled with Na[Mn(CO)₅] to afford bimetallic [Mn₂(CO)₆(S₂C·NHC)] clusters. Yet, the most convenient strategy to access these dinuclear Mn(0) products implied a direct carbonyl substitution from the [Mn₂(CO)₁₀] dimer. The molecular structures of three monometallic and four bimetallic compounds were elucidated by single crystal X-ray diffraction analysis. In the monometallic complexes, the NHC·CS₂ ligands exhibited a bidentate κ²-S,S' coordination mode with an S-C-S bite angle of about 116°. In the dinuclear clusters, the CS₂^- unit acted as a chelate toward one manganese center and as a pseudoallylic ligand toward the other one. The S-C-S bite angle was reduced to ca. 104°. Thus, the zwitterions displayed a remarkable flexibility, which also permitted a staggered arrangement of the carbonyl groups in the bimetallic systems. Examination of the [small nu, Greek, macron]_CO absorption bands on IR spectroscopy helped identify the presence of fac-Mn(CO)₃ or Mn₂(CO)₆ motifs, while the ¹³C NMR chemical shift of the CS₂^- moiety was a reliable indicator for monitoring its hapticity. Whereas the dinuclear clusters were air- and moisture-stable crystalline solids, mononuclear halido derivatives displayed only a limited stability under aerobic conditions. Both types of compounds underwent rather unselective, extensive fragmentations in the gas phase, in sharp contrast with the analogous rhenium derivatives that led to clean sequential decarbonylation processes upon collision-induced dissociation.