The solid- and solution-state structures of 2-nitrosopyridine and its 3- and 4-methyl derivatives

Autor:	Giuseppe Mele, Mark J. Maidment, Michael B. Hursthouse, Keith G. Orrell, Vladimir Šik, K.M. Abdul Malik, Brian G. Gowenlock, Giuseppe Vasapollo
Rok vydání:	2000
Předmět:	chemistry.chemical_compound Crystallography Monomer chemistry Stereochemistry Dimer Pyridine Proton NMR Crystal structure Kinetic energy Dissociation (chemistry) Spectral line
Zdroj:	Journal of the Chemical Society, Perkin Transactions 2. :2280-2286
ISSN:	1364-5471 1470-1820
Popis:	2-Nitrosopyridine, 1, 3-methyl-2-nitrosopyridine, 2, and 4-methyl-2-nitrosopyridine, 3, exist in organic solvents as monomer–azodioxy dimer equilibria with the dimers predominating at ambient temperatures. In the case of compounds 1 and 3 only the Z-dimers co-exist with the monomers, whereas for compound 2 both Z- (major) and E- (minor) dimers are present with the monomer. Variable temperature 1H NMR bandshape analysis and 2D-EXSY spectra of 1–3 provided thermodynamic and kinetic data for the dissociation equilibria Z- (or E-) dimer ⇌ 2 monomer, ΔH values being in the range 53–58 kJ mol−1 and ΔG‡ (298.15 K) values in the range 70–82 kJ mol−1. An X-ray crystal structure of 1 identified the compound as a Z-dimeric species with the two pyridine rings twisted by 62.7° and their heterocyclic N atoms pointing towards each other.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::905bc68c1c770e6c35eb5a4052d1a020 https://doi.org/10.1039/b004270f Zobrazit plný text záznamu