Fabrication of Large Single Crystals for Platinum-Based Linear Polymers with Controlled-Release and Photoactuator Performance.

Preparation of large single crystals of linear polymers for X-ray analysis is very challenging. Herein, we employ a coordination-driven self-assembly strategy to secure the appropriate head-to-tail alignment of anthracene moieties, and for the first time obtained large-sized Pt-based linear polymer crystals through a [4+4] cycloaddition of anthracene in a single-crystal to single-crystal fashion. Using X-ray diffraction to determine the polymer crystal structure, we found that both the polymerisation and depolymerisation steps proceed via a stable intermediate. Taking advantage of the temperature-dependent slow depolymerization, the Pt-based linear polymer showed potential as a sustained release anticancer drug platform. Utilizing the reversible contraction effect of unit-cell volume upon irradiation or heating, the stimuli-responsive crystals were hybridized with polyvinylidene fluoride to obtain a "smart material" with outstanding photoactuator performance.