Triphenylamine derivatives containing nitronyl nitroxide and iminyl nitroxide - Syntheses, characterization, crystal structures, and magnetic studies

Citation
Dq. Zhang et al., Triphenylamine derivatives containing nitronyl nitroxide and iminyl nitroxide - Syntheses, characterization, crystal structures, and magnetic studies, CHIN J CHEM, 19(10), 2001, pp. 966-975
Citations number
29
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Chemistry
Journal title
CHINESE JOURNAL OF CHEMISTRY
ISSN journal
1001-604X → ACNP
Volume
19
Issue
10
Year of publication
2001
Pages
966 - 975
Database
ISI
SICI code
1001-604X(200110)19:10<966:TDCNNA>2.0.ZU;2-9
Abstract
New triphenylamine derivatives 1, 2, 3, and 4 were synthesized and characte rized by IR, FAB-MS, EPR and EA. All of them displayed similar absorption a nd fluorescence spectra except compound 1, for which a possible explanation was proposed. Quasi-reversible oxidation waves at about 0.76 V (vs. SCE) a nd 1.1 V for nitronyl nitroxide and iminyl nitroxide respectively as well a s irreversible one at about 1.5 V for triphenylamine group were detected wi th cyclic voltammetry for compounds 1, 2, 3 and 4. Crystal structures of 2 and 4 were determined by X-ray diffraction analysis. Their crystal data are as follows: for 2: mono-clinic, C2/c, a = 1.69914 (4), b = 1.37435(5), c = 1.24621(5) nm, beta = 106.553(2)degrees, V = 2.7896(2) nm(3), Z = 4; for 4 : orthorhombic, Pbca, a = 1.95970(6), b = 1.33096 (4), c = 4.84691 (14) nm, V = 12.6421(7) nm(3), Z = 8. Magnetic studies indicated that all of them s howed antiferromagnetic properties in solid state, but with strong intermol ecular spin-spin coupling as indicated by the relatively large values of th eta, in particular for 4 (theta = - 12 K). Possible spin-spin interaction m echanism was suggested based on the crystal structures of 2 and 4.