128141-84-4Relevant academic research and scientific papers
4,4'-(BUTADIYNE-1,4-DIYL)-BIS-(2,2,6,6-TETRAMETHYL-4-HYDROXYPIPERIDIN-1-OXYL): A CONVENIENT SYNTHESIS AND A POLYMORPHIC TRANSFORMATION INDUCED BY IONIZING RADIATION
Hamill, Gregory P.,Yost, Elizabeth A.,Sandman, Daniel J.
, p. 339 - 346 (2007/10/02)
A new convenient synthesis of the diacetylenic nitroxide 4,4'-(butadiyne-1,4-diyl)-bis(2,2,6,6-tetramethyl-4-hydroxypiperidin-1-oxyl) (1) has been achieved by oxidative coupling of the relevant monoacetylene.In the presence of air, polycrystalline samples of the beta phase of 1 are converted to the alpha polymorph on exposure to radiation from Cu Kα or (60)Co sources.This polymorphic transformation is conveniently monitored by observing the X-ray powder diffraction pattern in the 2Θ range 6-13 deg.New synthetic procedures to the diacetylenic nitroxides 2,4-hexadiyn-1,6-diyl-bis(2,2,5,5-tetramethyl-1-oxyl-3-pyrolline-3-carboxylate) (3) and 5-(2,2,6,6-tetramethyl-1-oxyl-1,2,5,6-tetrahydropyridin-4-yl)penta-2,4-diyn-1-ol (4) are reported.
