15937-81-2Relevant articles and documents
Excimer Emission in Protonated Pyridine Systems. 2. Excimer Emission of Protonated Dipyridylalkanes in Solution at Room Temperature and 77 K
Handa, Takashi,Utena, Yoshio,Yajima, Hirofumi
, p. 5150 - 5154 (1984)
Emission properties of (2-pyridyl)-(CH2)n-(2-pyridyl) (n = 2, 3, 5, and 7) and (4-pyridyl)-(CH2)n-(4-pyridyl) (n = 2, 3, and 5) were studied in solution in the presence of trifluoroacetic acid at room temperature and 77 K.At room temperature, only 1,3-di(2-pyridyl)propane exhibits a very weak fluorescence at approximately 6900 cm-1 to the red of the normal fluorescence.This band is ascribed to an intramolecular excimer fluorescence between the protonated pyridine moieties.However, 4,4'-dipyridylalkanes do not fluoresce.At 77 K, being specific to a mixed solvent of tetrahydrofuran, methanol, and methyltetrahydrofuran (4:3:1 by volume), the protonated 2,2'-dipyridylalkanes exhibit a structureless band around around 325 nm besides the normal fluorescence band, but they exhibit no excimer fluorescence.On the other hand, the protonated 4,4'-dipyridylalkanes apparently exhibit only a structureless band around 325 nm.The 325-nm fluorescence band comes from a dimerlike excimer in which the protonated pyridine moieties interact intermolecularly in the excited state.The efficiency of the dimerlike excimer formation is independent of the length of methylene chain.From studies on the effects of solvent and temperature on the dimerlike excimer emission, it is found that the formation of the dimerlike excimer is strongly related to a solvent cage effect.
Gemini pyridinium surfactants: Synthesis and conductometric study of a novel class of amphiphiles
Quagliotto, Pierluigi,Viscardi, Guido,Barolo, Claudia,Barni, Ermanno,Bellinvia, Silvia,Fisicaro, Emilia,Compari, Carlotta
, p. 7651 - 7660 (2003)
A new series of pyridinium cationic gemini surfactants was prepared by quaternization of the 2,2′-(α,ω-alkanediyl)bispyridines with N-alkylating agents, whose reactivity is briefly discussed. Particularly useful was the use of long-chain alkyl triflates (trifluoromethanesulfonates) for both overcoming the sterical hindrance in the pyridines and obtaining higher synthetic yields. Well-known 4,4′-(α,ω -alkanediyl)bis(1-alkylpyridinium) structures showed narrow temperature ranges for practical applications, due to their high Krafft points, while the new 2,2′-(α,ω)-alkanediyl)bis-(1-alkylpyridinium) series, accounted for good surface active properties. Due to the Krafft points below 0 °C, they could be exploited as solutions in water at any temperature. The characterization of the behavior of the series was performed by conductivity measurements. Some of the proposed structures exhibited unusual surface active behavior, which was interpreted in terms of particular conformational arrangements.
Metal Acetylide Elimination: The Key Step in the Cascade Decomposition and Transformation of Metalated Propargylamines
Flynn, Matthew T.,Blair, Victoria L.,Andrews, Philip C.
, p. 1225 - 1228 (2018/04/30)
Metal acetylide elimination facilitates a novel one-pot cascade metalation and elimination/addition route to a series of unsymmetrical secondary amines from the reaction of secondary propargylamines with organometallic reagents. Spectroscopic evidence suggests a dimetalated amido intermediate rather than an allene.
HOMOLYTIC PYRIDYLETHYLATION OF CYCLOHEXANE AND TETRALIN
Il'yasov, E.A.,Galust'yan, G.G.
, p. 326 - 330 (2007/10/02)
The homolytic pyridylethylation of cyclohexene and tetraline with 2-vinylpyridine under conditions of peroxide and thermal initiation was investigated.In addition to the main reaction products, i.e., cycloalkylethylpyridines (1 : 1 adducts), compounds indicating rearrangement of the radicals with H migration were also isolated and identified.
