posted on 2021-03-10, 12:04authored byHo Fung Cheng, McKinley K. Paul, Andrea I. d’Aquino, Charlotte L. Stern, Chad A. Mirkin
We
studied a series of dynamic weak-link approach (WLA) complexes
that can be shuttled between two immiscible solvents and switched
between two structural states via ion exchange. Here, we established
that hydrophobic anions transfer cationic, amphiphilic complexes from
the aqueous phase to the organic phase, while a chloride source reverses
the process. As a result of the dynamic metal coordination properties
of WLA complexes, the denticity of these complexes (mono- to bi-)
can be modulated as they partition into different phases. In addition,
we discovered that heteroligated complexes bearing ligands of different
donor strengths preferentially rearrange into two homoligated complexes
that are phase-partitioned to maximize the number of stronger coordination
bonds. This behavior is not observed in systems with one solvent,
highlighting the dynamic and stimuli-responsive nature of hemilabile
ligands in a multiphasic solvent environment. Taken together, this
work shows that the highly reconfigurable WLA modality can enable
the design of biphasic reaction networks or chemical separations driven
by straightforward salt metathesis reactions.