99677-65-3Relevant academic research and scientific papers
Transanular Interaction in Phanes, 29. Models for Amine-Arene-Exciplexes: ?-? versus n-? Interaction in Isomeric Naphthalino(2,6)pyridinophanes andNaphthalino(2,6)pyridinophanes-1,11-dienes
Haenel, Matthias W.,Lintner, Birgit,Benn, Reinhard,Rufinska, Anna,Schroth, Gerhard,et al.
, p. 4884 - 4906 (2007/10/02)
The naphthalinopyridinophanes 5, 6 and the corresponding dienes 3, 4 were synthesized as models for exciplexes.From the dithiaphanes 10 and 12, prepared by cyclisation of 7 with 9 and 8 with 9, the phanes 5 and 6 were obtained by oxidation to the disulfones 11, 13 followed by vapour phase pyrolysis.Ring contraction of 10, 12 by S-analogous Wittig ether rearrangement led to 14/15 and 17/18, respectively. 14 and 17 were converted into the dienes 3 and 4 via oxidation to the sulfoxides 16, 19 and pyrolytic elimination of methanesulfenic acid.The 1H NMR data correspond to the perpendicular orientation of pyridine and naphthalene in 3, 4 and to more parallel arrangements of the aromatic units in 5, 6.For the conformational flipping of the pyridine ring in 5 an energy barrier ofΔH* = 11.84 +/- 0.15 kcal/mol and ΔS* = -1.70 +/- 0.58 cal K-1 mol-1 was obtained by temperature dependent 1H NMR and line shape analysis.The molecular structures of 3, 5, and 6 were determined by X-ray analysis.Absorption spectra and especially the red-shifted structureless fluorescence emissions typical for exciplexes show orientational dependencies and are discussed in terms of n-? interaction between pyridine nitrogen and naphthalene in 3, 4 and ?-? interaction between the aromatic units in 5, 6.
