The use of different solvents (Table ) reveals that the conversion can be drastically increased if alcohols are used as solvent (ethanol< iso-propanol< 1-octanol). Alcohols as solvents are well known to promote the disproportionation of Cu(I)X into Cu(0) and Cu(II)X which is a crucial step in SET-LRP. Additionally, more recent work of avoiding star-star coupling reactions shows that Cu(0) mediated controlled radical polymerization combines high-end group fidelity with fewer star-star coupling reactions observed. After several optimizations steps comparing different alcohol species as solvent using SET-LRP (supporting information) and ATRP, monomodal size distributions for conversions of more than 40% could be achieved, leading up to 41 repeating units of PtBAMA at each arm and a corresponding Ð of. < 1.4 (Figure and S5).