21945-40-4Relevant articles and documents
Configurational and constitutional information storage: Multiple dynamics in systems based on pyridyl and acyl hydrazones
Chaur, Manuel N.,Collado, Daniel,Lehn, Jean-Marie
experimental part, p. 248 - 258 (2011/03/21)
The C=N group of hydrazones can undergo E/Z isomerization both photochemically and thermally, allowing the generation of a closed process that can be tuned by either of these two physical stimuli. On the other hand, hydrazine-exchange reactions enable a constitutional change in a given hydrazone. The two classes of processes: 1) configurational (physically stimulated) and 2) constitutional (chemically stimulated) give access to short-term and long-term information storage, respectively. Such transformations are reported herein for two hydrazones (bis-pyridyl hydrazone and 2-pyridinecarboxaldehyde phenylhydrazone) that undergo a closed, chemically or physically driven process, and, in addition, can be locked or unlocked at will by metal-ion coordination or removal. These features also extend to acyl hydrazones derived from 2-pyridinecarboxaldehyde. Similarly to the terpydine-like hydrazones, such acyl hydrazones can undergo both constitutional and configurational changes, as well as metal-ion coordination. All these types of hydrazones represent dynamic systems capable of acting as multiple state molecular devices, in which the presence of coordination sites furthermore allows the metal ion-controlled locking and unlocking of the interconversion of the different states.
Electrochemical Synthesis of Heterocyclic Compounds. XV. Anodic Synthesis of s-Triazolopyridine Derivatives
Crljenak, Senka,Tabakovic, Ibro,Jeremic, Dragoslav,Gaon, Igor
, p. 527 - 536 (2007/10/02)
Anodic oxidation of several heterocyclic hydrazones (1a - 9a) prepared from 2-hydrazinopyridine of 2-hydrazino-4-nitropyridine and the corresponding aromatic aldehyde was performed in a CH3CN-Et4NClO4 solution with the addition of 60percent HClO4 on a platinum electrode, using controlled potentials.As a result of two-electron oxidative cyclizations, several s-triazolopyridine derivatives (1b - 9b) were prepared in yields ranging from 55 to 92percent.A mechanism rationalizing the formation of the 3-phenyl-s-triazolopyridine, 1b, has been studied by LSV, CPSV, RDE, coulometry and preparative scale electrolysis.
