Synthesis, Structure, Spectral Properties, and Electrochemistry of Bis(crown ether) Containing 1,3-Distyrylbenzenes
By V. N. Nuriev, O. V. Fedorov, A. A. Moiseeva, A. Ya. Freidzon, N. A. Kurchavov, A. I. Vedernikov, A. V. Medved’ko, E. S. Pod’yacheva, S. Z. Vatsadze, S. P. Gromov
The reaction of tetraethyl [1,3-phenylenedi(methylene)]bis(phosphonate) with formyl derivatives of benzocrown-ethers or formyl derivatives of o-dimethoxybenzene lead to high yield formation of the respectful bis(crown ether) containing 1,3-distyrylbenzenes or tetramethoxy-substituted 1,3-distyrenebenzenes. NMR spectra and quantum-chemical calculations showed the prevalence of unsymmetrical syn/anti,(syn,anti),syn/anti-conformations in 1,3-distyrylbenzenes. 1,3-Distyrylbenzenes absorb in shorter wavelength spectral region and have a weaker fluorescence than 1,4-distyrylbenzenes. The difficulty in the electrochemical reduction of 1,3-distyrylbenzenes comparing with 1,4-distyrylbenzenes is due to a less effective conjugation system in the metaderivatives.