Search results
Results from the WOW.Com Content Network
Structure of pyridine N-oxide. Oxidation of pyridine occurs at nitrogen to give pyridine N-oxide. The oxidation can be achieved with peracids: [94] C 5 H 5 N + RCO 3 H → C 5 H 5 NO + RCO 2 H. Some electrophilic substitutions on the pyridine are usefully effected using pyridine N-oxide followed by deoxygenation. Addition of oxygen suppresses ...
With a pK a of 5.25 for its conjugate acid, pyridine is about 15x less basic than imidazole. Pyridine is a weak pi-acceptor ligand. Trends in the M-N distances for complexes of the type [MCl 2 (py) 4] 2+ reveal an anticorrelation with d-electron count. [2]
Pyridine-N-oxides bind to metals through the oxygen. According to X-ray crystallography, the M-O-N angle is approximately 130° in many of these complexes. As reflected by the pKa of 0.79 for C 5 H 5 NOH +, pyridine N-oxides are weakly basic ligands. Their complexes are generally high spin, hence they are kinetically labile.
Structure of a representative imido complex (py = pyridine, CMe 3 = tert-butyl) [1] In coordination chemistry and organometallic chemistry, transition metal imido complexes is a coordination compound containing an imido ligand.
Structures and names of common heterocyclic compounds Pyridine, a heterocyclic compound. A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). [1]
The nitrogen (N)-containing aromatic rings can be separated into basic aromatic rings that are easily protonated, and form aromatic cations and salts (e.g., pyridinium), and non-basic aromatic rings. In the basic aromatic rings , the lone pair of electrons is not part of the aromatic system and extends in the plane of the ring.
In non-basic aromatic rings the lone pair of electrons of the nitrogen atom is delocalized and contributes to the aromatic pi electron system. In these compounds the nitrogen atom is connected to a hydrogen atom. Examples of non-basic nitrogen-containing aromatic rings are pyrrole and indole. Pyrrole contains a lone pair that is part of the pi ...
Pyridine N-oxide is five orders of magnitude less basic than pyridine: the pK a of protonated pyridine-N-oxide is 0.8. [7] Protonated derivatives are isolable, e.g., [C 5 H 5 NOH]Cl. [3] Further demonstrating its (feeble) basicity, pyridine-N-oxide also serves as a ligand in coordination chemistry.