Highly 3,4-selective living polymerization of 2-phenyl-1,3-butadiene with amidino N-heterocyclic carbene ligated rare-earth metal bis(alkyl) complexes

Abstract

2-Phenyl-1,3-butadiene was polymerized using an amidino N-heterocyclic carbene lutetium bis(alkyl) precursor in high 3,4-selectivity (96.9%) and a living mode to afford a new plastic polydiene with a high Tg of 56.1 °C.

In-chain functionalized syndiotactic 1,2-polybutadiene by a Ziegler–Natta iron(iii) catalytic system

“…As the representative 13 C NMR shown in Fig. 2, when 10% comonomer b was incorporated into the polymer chain, the syndiotactic rrrr pentad was maintained as high as 81.0%, which is about same with that of sPB homopolymers, 35 implying that the presence of polar comonomer displayed subtle inuence on the stereoselectivity of the iron(III) catalytic active species.…”

“…[30][31][32][33][34] Alternatively, this unique comonomer, i.e. functional-groupsubstituted 1,3-butadiene, can also be polymerized in a 3,4manner through a h 3 -coordinated p-allylic unit, 35 and therefore serves the best candidate for accessing functionalized sPB.…”

Extremely High Glass Transition Temperature Hydrocarbon Polymers Prepared through Cationic Cyclization of Highly 3,4‐Regulated Poly(Phenyl‐1,3‐Butadiene)

“…In the 1 H NMR spectrum of the P(2‐PB) prepolymer, the signal at 5.47 ppm is assigned to the internal olefinic protons of the 1,4‐structure, and the signals at 5.01 and 4.67 ppm are assigned to the pendant vinyl protons of the 3,4‐structure. Two highly 3,4‐regulated P(2‐PB) prepolymers were prepared (entries 2 and 3 in Table 1 ) and the 3,4‐structure content can be as high as 96.2% determined from 1 H NMR spectrum according to the previous study (Figure C). The 13 C NMR spectrum also confirmed that we obtained the highly 3,4‐regulated P(2‐PB) prepolymer (Figure S5, Supporting Information).…”

Recent Advances in Rare Earth Complexes Containing N-Heterocyclic Carbenes: Synthesis, Reactivity, and Applications in Polymerization

“…According to the analysis of in situ NMR spectra, the yttrium hydrido aluminate cation was speculated to be the active species. (72), Eu (73)). Alternatively, complexes 70-73 could also be prepared by one-pot reaction of the DLB proligand (H 3 DLB-Cl 2 ) with five equivalents of NaN(SiMe 3 ) 2 , followed by the treatment with LnCl 3 .…”