Non-covalent molecular tweezer/guest complexation with Pt(II)Pt(II) metal-metal interactions: toward intelligent photocatalytic materials

摘要

A new organoplatinum(II) molecular tweezer with a stimuli-responsive 2,20 :60 ,200 -terpyridine spacer has been synthesized, which undergoes ‘‘U’’- to ‘‘W’’-shaped conformational transition upon adding Zn2+ ions. The molecular tweezer receptor displays a high binding affinity toward the complementary guests, with the implementation of Pt(II)Pt(II) metal-metal interactions for the non-covalent tweezering systems. MMLCT absorbance simultaneously emerges in the visible-light region (470-620 nm), which can be sensitized by O2 and thereby utilized for photo-catalyzed reactions in organic and aqueous media. Moreover, temporally ‘‘on-demand’’ photo-catalytic efficiency can be accomplished, via the successive addition of Zn(OTf)2 and a competitive ligand to the supramolecular tweezering photosensitizers. Hence, the current study opens up new avenues toward intelligent photocatalytic materials via elaborate supramolecular engineering.