2 bromoisobutyric acid

2-Bromoisobutyric acid (98%), 2-bromoethanol (95%), 2-(dimethylamino)ethyl methacrylate (DMAEMA, 98%), poly-(ethylene glycol) methyl ether methacrylate (OEGMA, MW = 500), methacrylic acid (99%), N-(3-(dimethylamino)propyl)-N′-ethylcarbodiimide hydrochloride (EDC, ≥99%), N,N-dimethylamino pyridine (DMAP, ≥99%), copper bromide (≥99.99%), ascorbic acid, (AA, ≥99%) were purchased from Sigma-Aldrich. 2-(Methylthio)-ethanol (≥99%) was purchased from Alfa Aesar. Hydrogen peroxide solution (30%) was purchased from Fisher Scientific. All methacrylate monomers were passed through basic alumina columns before use. Tris(2-pyridylmethyl)amine (TPMA) was synthesized according to previous procedures.⁷⁶ All solvents and other chemicals were of reagent quality and were used as received unless special treatments discussed below were applied.

Acetone (>99.9%), 2-bromoisobutyric acid (98%), deuterium oxide (99.9%), 1,4-dioxane (>99.0%), ethanethiol (97%), ethyl acetate (>99.5%), n-hexane (>95%), potassium phosphate tribasic (K₃PO₄, reagent grade), sodium chloride (>99.5%), sodium trimethylsilylpropanesulfonate (DSS, 97%), and 3-(trimethoxysilyl)propyl methacrylate (98%) were purchased from Sigma-Aldrich and used as received. Dichloromethane (DCM, >99.5%), diethyl ether (99%, stabilized), hexanes (>98.5%), petroleum ether (Certified ACS, boiling range 40–60 °C), sodium sulfate (anhydrous, 99%), tetrahydrofuran (>95%, stabilized) were purchased from Fisher Scientific and used as received. Carbon disulfide (99.9%) was purchased from Acros Organics and used as received. Hydrochloric acid (36.5–38%, ACS grade) was purchased from Macron Fine Chemicals and diluted to 1 M with distilled water. D-chloroform (99.8% + 0.05% vol. tetramethylsilane (TMS)) was purchased from Cambridge Isotope Laboratories, Inc. and used as received. N-isopropyl acrylamide (Fisher Scientific, 98%, stabilized) was recrystallized thrice from hexanes and dried in vacuo to constant weight. Azobisisobutyronitrile (Sigma-Aldrich, 98%) was recrystallized from methanol thrice and dried in vacuo to constant weight.