

FOLLOWUS
a.Key Laboratory of Advanced Rubber Material, Ministry of Education, School of Polymer Science and Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
b.Shandong Provincial College Laboratory of Rubber Material and Engineering, School of Polymer Science and Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
c.Key Lab of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Lab of Rubber-plastics, School of Polymer Science and Engineering, Qingdao University of Science & Technology, Qingdao 266042, China
d.Suzhou Uropod Precision Instruments Technologies Co., Ltd., Suzhou 215137, China
fangliang@qust.edu.cn (L.F.)
wangxj@qust.edu.cn (X.J.W.)
cyzhang@qust.edu.cn (C.Y.Z.)
Received:22 December 2025,
Accepted:20 January 2026,
Online First:17 April 2026,
Published:05 May 2026
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Liu, Y.; Liu, Y. G.; Xu, J. X.; Yang, Q.; Zhao, W. P.; Fang, L.; Wang, X. J.; Liu, H.; Zhang, C. Y.; Zhang, X. Q. Iron-based catalysts catalyzing isoprene polymerization: the effect of conjugated groups in cyanide-containing electron donors. Chinese J. Polym. Sci. https://doi.org/10.1007/s10118-026-3581-1
Yao Liu, Yao-Guang Liu, Jun-Xin Xu, et al. Iron-based Catalysts Catalyzing Isoprene Polymerization: The Effect of Conjugated Groups in Cyanide-containing Electron Donors[J/OL]. Chinese Journal of Polymer Science, 2026, 441-11.
Liu, Y.; Liu, Y. G.; Xu, J. X.; Yang, Q.; Zhao, W. P.; Fang, L.; Wang, X. J.; Liu, H.; Zhang, C. Y.; Zhang, X. Q. Iron-based catalysts catalyzing isoprene polymerization: the effect of conjugated groups in cyanide-containing electron donors. Chinese J. Polym. Sci. https://doi.org/10.1007/s10118-026-3581-1 DOI:
Yao Liu, Yao-Guang Liu, Jun-Xin Xu, et al. Iron-based Catalysts Catalyzing Isoprene Polymerization: The Effect of Conjugated Groups in Cyanide-containing Electron Donors[J/OL]. Chinese Journal of Polymer Science, 2026, 441-11. DOI: 10.1007/s10118-026-3581-1.
In this study
the coordination pathways and decomposition behavior of azo-containing dicyano compounds within Fe(acac)
3
/Al
i
Bu
3
/donor ternary catalyst systems were systematically investigated
via in situ
Raman spectroscopy. Additionally
the modulating effect of conjugated moieties on the coordination interaction between cyanide groups and Fe ions was examined in detail. Experimental results demonstrate that isoprene polymerization catalyzed by azodicyanide mediated Fe-based catalytic systems proceeds
via
a coordination polymerization mechanism. Notably
the azo group does not directly participate in the coordination process; instead
it exerts a regulatory influence on the coordination capacity of the cyano group. Although thermal decomposition of the azo group occurs at elevated temperatures
it fails to initiate free radical polymerization of the isoprene monomer. Conjugated moieties including azo
vinyl
and benzene rings exert distinct impacts on the cyanide group. As electron-donating species
their Raman spectral characteristics reflect varying influences on cyanide coordination behavior. Density functional theory (DFT) calculations demonstrate that AIBN with azo groups as the conjugated moiety exhibits the most negative Gibbs free energy (Δ
G
°=–222.71 kcal·mol
–1
) for the coordination reaction with Fe
2+
indicating that the cyano groups in the azo-containing compound possess the strongest coordination capability with Fe
2+
. The coordination effects of conjugated groups on the cyanid
e center follow the sequence: azo
>
carbon-carbon double bond
>
benzene ring
where azo groups show the most significant coordination enhancement. These theoretical findings are consistent with the observed polymerization activity
suggesting that rational design of electron donors can be guided by theoretical calculations.
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