Close O-O contacts make me redder. The tetrafurylethene AIE luminogen has a strong red morphochromism going from the aggregate to the crystalline phase (27 nm). In this joint study with the group of B.-Z. Tang in Honk-Kong University of Science and Technology, which started with the visit of L. Viglianti in 2018, Lluís Blancafort and Alexander Voityuk from the IQCC show that it is due to unusually short OO contacts that are facilitated by circularly delocalized π electron density between the furan rings.
It was published recently in Angewandte Chemie-International Edition:
L. Viglianti, N. Xie, H.H.Y. Sung, A.A. Voityuk, N.L.C. Leung, Y. Tu, C. Baldoli, I.D. Williams, R.T.K. Kwok, J.W.Y. Lam, E. Licandro, L. Blancafort, and B.Z. Tang
“Unusual Through-Space Interactions between Oxygen Atoms Mediate Inverse Morphochromism of an AIE Luminogen”
Angew. Chem. Int. Ed. 2019, ASAP- [abstract]