Self-assembly via intermolecular hydrogen-bonding between o-/m-/p-NH2 and BF2 groups on dipyrromethenes.
Shin, Ji-Young; Patrick, Brian O.; Dolphin, David
Boron difluoride dipyrromethenes bearing configurationally different amine groups on a meso-phenyl ring were prepared and crystallized. The ortho- and para-amino groups allow the phenyl group to inductively release greater electron density into the dipyrromethenes resulting in relatively strong intermolecular hydrogen-bonding with the terminal BF2 groups, whereas the meta-analog formed weaker hydrogen-bonds. The intensities of the 1H NMR peaks in concentrated solutions all increased with F-decoupling