화학공학소재연구정보센터
Journal of the American Chemical Society, Vol.141, No.7, 3240-3248, 2019
A Concise Synthetic Strategy for Accessing Ambient Stable Bisphenalenyls toward Achieving Electroactive Open-Shell pi-Conjugated Materials
Open-shell, pi-conjugated molecules represent exciting next-generation materials due to their unique optoelectronic and magnetic properties and their potential to exploit unpaired spin densities to engineer exceptionally close pi-pi interactions. However, prior syntheses of ambient stable, open shell molecules required lengthy routes and displayed intermolecular spin-spin coupling with limited dimensionality. Here we report a general fragment-coupling strategy with phenalenone that enables the rapid construction of both biradicaloid (Ph-2-s-IDPL, 1) and radical [10(OTf)] bisphenalenyls in <= 7 steps from commercial starting materials. Significantly, we have discovered an electronically stabilized pi-radical cation [10(OTf)] that shows multiple intermolecular closer-than-vdW contacts (<3.4 angstrom) in its X-ray crystal structure. DFT simulations reveal that each of these close pi-pi interactions allows for intermolecular spin-spin coupling to occur and suggests that 10(OTf) achieves electrostatically enhanced intermolecular covalent-bonding interactions in two dimensions. Single crystal devices were fabricated from 10(OTf) and demonstrate average electrical conductivities of 1.31 X 10(-2) S/cm. Overall, these studies highlight the practical synthesis and device application of a new pi-conjugated material, based on a design principle that promises to facilitate spin and charge transport.