Synthetic and Natural Sources of the Pyridine Ring

Noncovalent Interactions of Ni+ with N-Donor Ligands (Pyridine, 4,4′-Dipyridyl, 2,2′-Dipyridyl, and 1,10-Phenanthroline): Collision-Induced Dissociation and Theoretical Studies

“…The calculated values for the Ni + (pyridine) x complexes, where x = 2−4, are systematically lower than the experimentally determined values, by 36.1, 29.2, and 52.6 kJ/mol, respectively. A similar but slightly smaller discrepancy between the theoretical and experimental BDEs was also found for Cu + ( N -L) x complexes where x = 3 and 4 to these ligands as well as to imidazole and acetone. − It is unclear why the agreement between theory and experiment is less satisfactory when the late transition metals, Cu + and Ni + , bind to two or more ligands. A comparison of the experimental and theoretical BDEs determined at the B3LYP/6-311+G(2d,2p) level yields a mean absolute deviation (MAD) for the Ni + (pyridine) x complexes of 30.0 ± 21.0 kJ/mol, significantly larger than the average experimental uncertainty (AEU) of 5.8 ± 2.6 kJ/mol for these complexes.…”

“…Metal complexes of these ligands have been investigated in the context of numerous biological applications, − environmental issues, , electrochemical applications, and supramolecular chemistry. , Studies of the coordination chemistry of transition metal complexes with polypyridyl bridging ligands such as 4,4′-dipyridyl, 2,2′-dipyridyl, and 1,10-phenanthroline are also important because of their potential as building blocks for supramolecular assemblies directed by either metal coordination or other intermolecular electronic interactions. − 2,2′-Dipyridyl has been found to be quite useful for a variety of biological applications. Raphael et al have synthesized peptide nucleic acid oligomers containing up to three adjacent 2,2′-dipyridyl ligands and examined their interactions with Ni 2+ .…”

Reaction Chemistry of Solid-State Pyridine Thin Films with Vapor Deposited Ag, Mg, and Al

“…The chemistry of aromatic heterocycles with reactive metals such as Ag, Mg, and Al as atoms, ions, colloids, and in the bulk has been of interest in many scientific disciplines including surface chemistry, organometallic chemistry, − environmental science, interstellar chemistry, and biological systems. − The simplest and best understood aromatic heterocyclic system is pyridine. To date, most studies of the chemistry between pyridine and reactive metals such as Ag, Mg, and Al have been performed on single pyridine molecules with metal atoms or cations in the gas ,,− or solution phases, or in theoretical studies for pyridine in similar limited environments. ,,,,− Although previous work has provided considerable insight into this area, comparably little is known about the reaction chemistry of solid-state pyridine films with such metals.…”

NHC-Promoted Asymmetric β-Lactone Formation from Arylalkylketenes and Electron-Deficient Benzaldehydes or Pyridinecarboxaldehydes

“…The formation of chiral pyridine containing compounds is of significance due both to their use in asymmetric catalysis and their appearance in biologically relevant molecules . Although a number of methods have previously been developed to prepare these motifs, enantiomerically enriched pyridyl substituted β-lactones, to the best of our knowledge, are unreported …”