H2S-releasing polymers with an acyl-protected perthiol chain terminus were prepared using a simple, high yielding end-group modification process.

Release of a photoactive Re(i) complex from a polymer star via ketimine linkages gives improved phototoxicity.

Synthesis and Characterization Methods A. MaterialsOligo(ethylene glycol) methyl ether methacrylate (OEGMA) with M n = 300 g mol -1 or 500 g mol -1 (denoted as OEGMA 300 or OEGMA 500 where relevant) were purchased from Sigma-Aldrich and deinhibited by percolating over a column of basic alumina. 2-(dimethylamino)ethyl methacrylate (DMAEMA) and 2-(diisopropylamino)ethyl methacrylate (DIPMA) were purchased from Sigma-Aldrich and passed through a column of basic alumina in order to remove inhibitor. Azobisisobutyronitrile (AIBN) was purified by recrystallization from methanol before use. 4-Cyano-4-(phenylcarbonothioylthio)pentanoic acid (CPADB), hydrazine monohydrate, poly(ethylene glycol) methyl ether thiol (PEG-SH) (M n = 2000 g mol -1 ), and 5,5'-dithio-bis(2-nitrobenzoic acid) were purchased from Sigma-Aldrich at the highest purity available and were used as received. Sodium nitrite (NaNO 2 ) and sulphuric acid (98%) were purchased from Ajax Finechem and RCI Labscan, respectively, and used as received. Petroleum ether (b.p. 40 -60 °C), diethyl ether, toluene, dimethylformamide and dioxane were purchased from Merck Millipore and used as received. 5,6-diaminofluorescein (D0084, Chemodex Customized Molecules) was obtained from Sapphire Biosciences (Sydney, Australia).