223433-03-2Relevant academic research and scientific papers
Synthesis, X-ray structure analysis and topochemical photopolymerization of substituted 1,6-bis(2,5-dimethoxyphenyl)hexa-2,4-diynes
Irngartinger, Hermann,Skipinski, Markus
, p. 917 - 922 (2007/10/03)
The 1,6-bis(2,5-dimethoxyphenyl)hexa-2,4-diynes 4a-c were obtained from the corresponding 2,5-dimethoxybenzenes 1 by bromination followed by a copper-catalyzed Grignard reaction with 3-bromoprop-1-yne. Catalyzed coupling of the resulting 3-(2,5-dimethoxyphenyl)prop-1-ynes 3 under Hay conditions gave the hexa-2,4-diynes 4a-c in good yields. The molecular structures of the diynes 4a and 4b were determined by X-ray diffraction analysis. In each crystal structure, an unusual 1,6-synperiplanar conformation of the hexa-2,4- diyne unit is observed, with the 1,6-diphenyl substituents arranged in a coplanar orientation. According to the crystal structure data obtained, irradiation of diynes 4a and 4b afforded the deeply-colored, highly-ordered polymers 5a and 5b under topochemical control. Oxidation of 4a and 4b with cerium(IV) ammonium nitrate gave the corresponding 1,6-bis(2,5- dimethoxyphenyl)hexa-2,4-diyne-1,6-diones 6a and 6b.
