Abstract
Reaction of guaiazulene ( 1) with thiophene-2,5-dicarbaldehyde ( 2) in methanol in the presence of hexafluorophosphoric acid at 25 °C for 3 h gives as high as 90% isolated yield of the delocalized dicarbenium-ion compound, 2,5-thienylenebis(3-guaiazulenylmethylium) bis(hexafluorophosphate) ( 3). Similarly, reaction of 1 with furan-2,5-dicarbaldehyde ( 4) under the same conditions as the above reaction affords the corresponding dicarbenium-ion compound, 2,5-furylenebis(3-guaiazulenylmethylium) bis(hexafluorophosphate) ( 5), in 84% isolated yield. Along with a facile preparation and the spectroscopic and electrochemical properties of 3 and 5, comparative studies on the 1H and 13C NMR spectral and chemical properties of 3 and 5 with those of the delocalized mono- and dicarbenium-ion compounds [i.e., (3-guaiazulenyl)(2-thienyl)methylium hexafluorophosphate ( 7), (2-furyl)(3-guaiazulenyl)methylium hexafluorophosphate ( 9), α,α′-bis(3-guaiazulenylmethylium) bis(tetrafluoroborate) ( 10), 1,2-phenylenebis(3-guaiazulenylmethylium) bis(hexafluorophosphate) ( 11), and 1,4-phenylenebis(3-guaiazulenylmethylium) bis(tetrafluoroborate) ( 12)] are reported. Moreover, referring to the results of the X-ray crystallographic analyses of 7, 9, 11, and 12, the optimized 2,5-thienylenebis(3-guaiazulenylmethylium)- and 2,5-furylenebis(3-guaiazulenylmethylium)-ion structures for 3 and 5, calculated by a WinMOPAC (version 3.0) program using PM3 as a semiempirical Hamiltonian, are described.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.