## 3 Results and Discussion
Comparison of the reactions performed at 70 \({}^{\circ}\)C (Figure 3b,d) revealed that polymerization in A (opened asterisk) occurred with a significant improvement in conversion relative to that in T (closed asterisk), presumably as a result of consumption of both the vinyl and benzyl chloride moieties on the VBC inimer. These findings suggest that the AT-SCVP proceeded in A at 70 \({}^{\circ}\)C.  
Figure 4 displays the \({}^{1}\)H NMR spectra of the products of SCVP performed in T and A at 50, 70, and 110 \({}^{\circ}\)C. The peak near 4.5 ppm represents both the un-reacted and chain-ending benzyl chloride moieties (_i.e._, linear and terminal units), while that near 2.8 ppm represents the reacted ones (_i.e._, branched units). In the case of the poor solvent for Cu (II)/Bpy (Figure 4a), we obtained a polymer with un-reacted and terminal benzyl chloride moieties, but nearly no branched points, at low temperature. This result indicates that P(St-_co_-VBC) with a predominantly linear structure formed through AT-FRP. In the good solvent for Cu (II)/Bpy (Figure 4b), a typical SCVP process occurred readily; we observed signals for linear, terminal, and branched units, indicating a branched polymer structure. Figure S1 presents \({}^{1}\)H NMR spectra of linear PVBC and hyperbranched PVBC polymers. The broad signals of the protons of the aromatic rings (7.4-6.4 ppm) and benzyl chloride moieties (_ca_. 4.5 ppm) provided additional evidence for the non-linear structure, suggesting a complicated mixture of different chemical environments for the benzyl chloride moieties. These results are  
Figure 3: AT-SCVP kinetic plots of comonomers (St, VBC) in a single solvent (**a**,**b**) T and (**c**,**d**) A at various temperatures (50, 70, and 110 \({}^{\circ}\)C). consistent with the trends in Figure 3 and illustrated that control over different polymer topologies can be achieved merely by tuning the catalyst solubility through changes in temperature or solvent polarity. Thus, we further examined the switching from AT-FRP to SCVP in a one-pot procedure. Figure 5 displays the kinetic plot for the manipulation of the polymer topology through an increase in temperature. The consumptions of St and VBC were determined through GC analysis. After reacting for 5 h in T at 70 \({}^{\circ}\)C, the mixture was heated to 110 \({}^{\circ}\)C rapidly and then heated at that temperature for another 19 h. Figure 5a reveals ramped increases in the conversions of St and VBC upon increasing the temperature, reaching approximately 18% and 36%, respectively. Figure 5b reveals the progress in the molecular evolutions and broad molecular weight distributions (\(D=1.43\)-\(1.65\)) for samples (1)-(3) in Figure 5a. Figure S2 displays the results of two one-pot reactions in which manipulations of polymer the topology were performed through increases in temperature. Figure S2a (from 70 \({}^{\circ}\)C/1 h to 110 \({}^{\circ}\)C/+23 h) reveals that the conversions of St and VBC reached approximately 40% and 66% after the additional reaction time. In contrast, Figure S2b (from 70 \({}^{\circ}\)C/24 h to 110 \({}^{\circ}\)C/+24 h) reveals almost unchanged conversions of St (_ca._ 30%) and VBC (_ca._ 55%). These results indicate that a suitable temperature and period of time are required to maintain the presence of propagating radicals in the reaction medium to allow the catalyst phase transfer AT-SCVP procedure to occur. We used \({}^{1}\)H NMR spectroscopy to analyze the microstructures of the resulting branched polymers in Figures 5 and S2. Figure 6A-C reveals that the catalyst-phase-transfer AT-SCVP procedures can be distinguished. According to the signals of linear (A\({}_{4.5}\)), terminal (A\({}_{4.4}\)), and branched units (A\({}_{2.8}\)), we estimated the FB through Equation (1) and the BI through Equation (2). We found that the FBs and BIs followed the same order: \(6\mathrm{C}>6\mathrm{B}>6\mathrm{A}\). A higher FB resulted from greater consumption of the VBC inner. The trends are consistent with the GC results in Figures 5 and S2.