Self-Associating Curved π‑Electronic Systems with Electron-Donating and Hydrogen-Bonding Properties

Curved π-electronic molecules,
dipyrrolylbenzodiazepines
(dpbs), were synthesized via condensation of 1,3-dipyrrolyldiketones
and phenylenediamines. Dpbs exhibited 1D hydrogen-bonding chains between
pyrrole NH and diazepine N and the resulting packing structures in
the solid state. The pyrrole and diazepine N sites coordinate RhI, providing curved π-electronic systems of increasing
rigidity. Dpb underwent coassembly with C60, which was
surrounded by a hydrogen-bonding ring structure of six dpbs. On photoexcitation,
the coassembly exhibited ultrafast electron transfer from the dpb
moiety to C60, depending on their proximal arrangement
as well as electron-donating and -accepting properties.