5440-92-6Relevant articles and documents
Structural features of tetraazathiapentalenes fused with pyrimidine and/or pyridine rings. Experimental evaluation of the nature of hypervalent N-S-N bond by restricted internal rotation of the pyrimidine ring
Ohkata, Katsuo,Ohsugi, Minoru,Yamamoto, Kazuhiro,Ohsawa, Mika,Akiba, Kin-Ya
, p. 6355 - 6369 (2007/10/03)
A series of neutral (8-10), monomethylated (12-14), and dimethylated (17) 10-S-3 sulfuranes, derivatives of tetraazathiapentalenes fused with pyrimidine and/or pyridine ring, were prepared. These molecules are planar, and bond energies of the hypervalent
Molecular Conformation of N,N'-Diarylthioureas: an Assessment by 1H NMR and Infrared Spectroscopy
Sudha, L. V.,Manogaran, S.,Sathyanarayana, D. N.
, p. 591 - 596 (2007/10/02)
Several N,N'-dipyridyl- and N-phenyl-N'-pyridyl-thioureas were examined in different solvents at various temperatures by 1H NMR in order to study their conformational properties.The influence of concentration and the methyl substituent in the pyridine ring on the chemical shifts of the NH and pyridine groups was investigated.The observed chemical shifts are analysed in terms of the conformational properties of the molecules.Free energy barriers to the internal rotation about the C-N bonds have been determined.Infrared spectra have been measured to supplement the NMR studies.Intramolecular hydrogen bonding played a major role in the preferred conformation of pyridylthioureas.The data further revealed an interesting dynamic exchange phenomenon occuring in symmetric N,N'-dipyridylthioureas between two intramolecularly hydrogen bonded conformers.
