Phthalimide potassium salt

Phosphorus tribromide 99% (Sigma-Aldrich Co., St. Louis, MO, USA), Phthalimide potassium salt 98% (Sigma-Aldrich Co., St. Louis, MO, USA), Hydrazine monohydrate 98% (Sigma-Aldrich Co., St. Louis, MO, USA), 2,4-toluene diisocyanate (TDI) (BASF, Ludwigshafen, Germany), isophorone diisocyanate (IPDI) (Evonik Chemistry Ltd., Essen, Germany), oligotetramethylene oxide diol (OTMO; BASF, Ludwigshafen, Germany) with M_n ~ 1008 g∙mol⁻¹, M_n ~ 1400 g∙mol⁻¹, glycidol (grade pure, 99.0%, Research Institute of Polymer Materials, Perm, Russia), Dibutyltin dilaurate (grade pure, 99.8%) were used without purification.

N-hexane (95%), THF (99.9%), and dichloromethane were purchased from Th. Geyer (Renningen, Germany); methanol and acetonitrile (HPLC-grade) were purchased from VWR (Darmstadt, Germany)); N,N-dimethylformamide (DMF, 99%) was purchased from Acros Organics (Geel, Belgium); anhydrous 1,2-dichlorobenzene (DCB, 99%), methanol (HPLC-grade), cobalt carbonyl (Co₂(CO)₈) containing 1%–5% n-hexane as stabilizer, hydrazine monohydrate (N₂H₂ 64%–65%), 2,2′-bipyridyl (99%), styrene (99%), α,α′-dichloro-p-xylene (98%), 18-crown-16 (99%), phthalimide potassium salt (99%), copper(I) chloride (97%), and alumina (activated, neutral, Brockmann Activity I) were purchased from Sigma Aldrich (Steinheim, Germany) and used as received without further purification. copper(I) chloride was purified by stirring in glacial acetic acid overnight, washed with ethanol and dried under vacuum. Co₂(CO)₈ was kept in the fridge of a glovebox, and n-hexane evaporated in the glovebox before use. styrene was passed through a short column of neutral alumina to remove inhibitors and deoxygenated by bubbling with N₂ before starting a polymerization.

Phthalimide potassium salt (98%) was used as purchased from Sigma-Aldrich (Munich, Germany). The starting (3-chloropropyl)triethoxysilane was purchased from Sigma-Aldrich (Munich, Germany). Deionized water (resistivity ≥ 17.5 MΩ∙cm, Vodoley-M water purifier, RU) was used for the silsesquioxane synthesis.