Solvent- and Temperature-Responsive Platinum(II)-Functionalized Flexible Lewis Pairs.

Metal-functionalized flexible Lewis pair (flexLP) complexes are described. Platinum(II) terpyridine (Pt-tpy) units added to a flexLP backbone through copper(I)-catalyzed coupling reactions yield monometallic (1) and bimetallic (2) Pt-tpy flexLP complexes. NMR and UV-vis absorption studies demonstrate that the complexes switch between the open unbound Lewis pair and closed Lewis adduct with solvents of varying hydrogen-bond-donating (HBD) strength as well as varying temperature. The charge-transfer (CT) energies of the complexes can be tuned by controlling the equilibrium between open and closed forms, demonstrating the ability to alter the photophysical behavior of the metal complexes by stimuli-responsive flexLP ligands.