Tetrahedral rigid core antenna chromophores bearing bay-substituted perylenediimides

[摘要] Two new representative methane- and adamantane-centered 'antenna' tetramers bearing bay-substituted pi-conjugated phenylethynyl-perylenediimides (PDICCPh) as chromophoric subunits, tetra-kis-[1-(4-ethynylphenyl)-N,N'-bis(1-hexylheptyl)-perylene-3,4:9,10-tetracarboxylic diimide]-methane (1) and tetrakis-1,3,5,7-[1-(4-ethynylphenyl)-N,N'-bis(1-hexylheptyl)-perylene-3,4;9,10-tetracarboxylic diimide]-adamantane (2), have been synthesized and their structural aspects have been thoroughly investigated by NMR spectroscopy. These PDI tetramers (1 and 2) represent the first successful example of incorporating the bay-substituted phenylethynyl-perylenediimides into the large rigid core tetrahedral frameworks. In these PDI tetramers, dynamic NMR experiments revealed the existence of perylene-centered conformational dynamic equilibrium (Delta G(not equal)=15-17 kcal/mol), the primary cause of the observed spectral broadening in conventional H-1 NMR spectra (295 K). In addition, PDI tetramers 1 and 2 were found to possess exceptional (photo)chemical stability, and their corresponding photophysical properties (epsilon(max) 180,000; tau(FL)=6.9 ns; Phi(FL)similar to 60%) make them viable candidates for various photonic applications and are in good agreement with other related multichromophoric PDI-based systems. (C) 2015 Elsevier Ltd. All rights reserved.

[发布日期] 2015-12-23

[关键词] Perylenediimide;Rigid core chromophores;Sonogashira coupling;Dynamic NMR;Conformational exchange