Postassembly Modification of a Pd<sub>6</sub> Host and C<sub>70</sub> Encapsulation to Enhance Its ROS-Mediated Terpene Oxidation Ability under Visible Light
Soumya Dey, Ranit Banerjee, Neal Hickey, Partha Sarathi Mukherjee
Abstract
The properties of supramolecules can be modulated by post-assembly modification (PAM) of their building blocks or via guest encapsulation. This work demonstrates a largely uncharted approach to property modulation that integrates both PAM and guest encapsulation in a single system to boost photocatalytic activity. Self-assembly of a “phenothiazine”-functionalized ligand ( L ) with a cis -blocked Pd(II) acceptor ( A ) generated an A 6 L 3 trifacial tube ( T ). Postassembly, T could be modified via irradiation with violet light, leading to the sulfoxidation of the “phenothiazine” moieties in T and thereby generating an oxidized tube ( TO ). Both TO and T could stabilize a C 70 molecule within their cavities, forming C 70 @TO and C 70 @T, respectively. Although T showed relatively poor photocatalytic performance mediated by reactive oxygen species (ROS) with respect to oxidation of terpenes ( S1–S4 ) under visible light, the modified TO was much better in that regard. Expectedly, C 70 @T showed better photocatalytic performance than T due to the presence of photosensitizing C 70 . While PAM or guest encapsulation alone led to reasonable improvements in photocatalytic ability, their combination within C 70 @TO led to a significant improvement. Catalytic amounts of C 70 @TO could instantly oxidize terpenes. Thus, we report here a new host that integrates the effects of both PAM and photosensitizer encapsulation for synergistically boosting its photocatalytic activity.