Linear Coordination Polymer Synthesis from Bis-Catechol Functionalized RAFT Polymers

Abstract

Catechol-Fe(III) complexes contain some of the strongest known metal-chelate coordination bonds. Despite this, they have until now not been utilized in (polymeric linker) linear coordination polymer (LCP) synthesis. With the view of generating catechol end-functional polymers, a new, symmetrical bis-catechol functionalized trithiocarbonate reversible addition fragmentation chain transfer (RAFT) agent is synthesized (CatDMAT). Acrylamide (AM) and dimethylacrylamide (DMA) polymerizations are conducted with CatDMAT using direct photoactivation RAFT polymerization to yield bis-catechol end-functionalized homo- and block-copolymers of molecular weight 10-15 kDa. Catechol-Fe(III) LCPs are successfully formed from the telechelic catechol polymers by bis-complexation to Fe(III). The tetrahedral bis-complex is detected by UV-vis spectroscopy (λ_max = 570 nm), while increases in relative viscosity and M_n,GPC over their respective uncomplexed polymers confirm the occurrence of supramolecular polymerization. The catechol-LCPs are shown to undergo oxidation and crosslinking in aqueous solution after 24 h.

Keywords: RAFT; catechol; coordination polymer.