## 4 Conclusions  
DFT calculations were performed to study the regioselectivity of the vinyl bond reaction of the copolymerization of propylene and the _bis_-styrene molecules. The calculations revealed that, when hydrogen is introduced to reactivate the inactivated catalyst and the vinyl bond containing DVB or BVPE is inserted, the second vinyl bond is inserted into the polymer in a rare 1,2 manner. This study yielded the following insights into the mechanism: (I) Upon insertion of the first vinyl bond of the DVB or BVPE into the Zr-C (PP\({}_{1}\)), its second vinyl bond is more inclined to be inserted in the 1,2 mode. (II) The 2,1 insertion is thermodynamically and kinetically unfavorable for DVB-PP\({}_{1}\) or BVPE-PP\({}_{1}\), as the Zr-C\({}_{1}\) bond should rotate 180\({}^{\circ}\) to complete the insertion before the second insertion take place; thus, the 1,2 insertion is easier to complete. Because the 1,2 insertion is the preferred mode for the bulk DVB-PP\({}_{1}\) or BVPE-PP\({}_{1}\), in terms of both the kinetics and thermodynamics, it leads to a growth polymer with an irregularity and region selectivity of the second vinyl bond insertion into the PP\({}_{1}\). (III) The analysis of the local reactivity index and Fukui functions also indicate that the 1,2-insertion mode is the optimal insertion mode. A detailed mechanistic study of this is important in understanding the chain transfer copolymerization, and to develop a functionalization strategy for PP polymers.  
**Supplementary Materials:** The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/catal12091039/s1](https://www.mdpi.com/article/10.3390/catal12091039/s1)]([https://www.mdpi.com/article/10.3390/catal12091039/s1](https://www.mdpi.com/article/10.3390/catal12091039/s1)). Figure S1: The relative free energy for the insertions of propylene into the Zr\(-\)C bond of [Zr]\(-\)CH\({}_{3}\). Figure S2: Optimized structures of the key TSs and intermediates (IMs) shown in Figure S1. Figure S3: The relative free energy for the insertions of DVB or BVPE into the Zr\(-\)C bond of [Zr]\(-\)PP\({}_{1}\). Figure S4: Optimized structures of the key TSs and products shown in Figure S3. Figure S5: The relative free energy for the insertions of propylene into the Zr\(-\)C bond of [Zr]\(-\)DVB\(-\)PP\({}_{1}\) or [Zr]\(-\)BVPE\(-\)PP\({}_{1}\). Figure S6: Optimized structures of the key TSs and products shown in Figure S5. Table S1: Detailed data of the local reactivity index and Fukui functions values for some molecules. Table S2: Energies and Cartesian coordinates of all the structures.  
**Author Contributions:** Conceptualization, S.-Y.Y. and C.-G.Z.; data curation, S.-Y.Y., X.P., and F.W. ([PERSON]); formal analysis, J.C. and F.W. ([PERSON]); funding acquisition, F.W. ([PERSON]), J.C., and C.-G.Z.; investigation, S.-Y.Y. and F.W. ([PERSON]); and project administration, C.-G.Z. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This work was financially supported by the Science and Technology Project of Hebei Education Department (ZD2021090), the National Science Foundation of China (21303078), the S&T Program of Hebei (B2020408007), the Science and Technology Research Projects of Langfang Normal University (XBQ202011), and the fundamental research funds for the universities in Hebei Province (JYT202101).  
**Data Availability Statement:** The data presented in this study are available in the Supplementary Materials.  
**Conflicts of Interest:** The authors declare no conflict of interest.