In:
Dalton Transactions, Royal Society of Chemistry (RSC), Vol. 51, No. 19 ( 2022), p. 7723-7731
Abstract:
A series of bis(alkyl) complexes {( t Bu)C[N(2,6-Me 2 C 6 H 3 )] 2 }Ln(CH 2 SiMe 3 ) 2 (THF) n (Ln = Y, n = 1 (1); Ln = Sc, n = 1 (2)), {2-[Ph 2 P(O)]C 6 H 4 NC( t Bu)N(2,6-Me 2 C 6 H 3 )}Sc(CH 2 SiMe 3 ) 2 (3), {2-[Ph 2 P(NPh)]C 6 H 4 NC( t Bu)N(2,6-Me 2 C 6 H 3 )}Sc(CH 2 SiMe 3 ) 2 (4) coordinated by bidentate (N,N) and tridentate (N,N,O; N,N,N) amidinate ligands are synthesized using an alkane elimination approach. Yttrium complex 1 demonstrated a half-life of ∼2.5 days at room temperature in benzene-D6 (C 6 D 6 ) solution, whereas scandium complexes proved to be much more stable (25 d (2), 30 d (3) and 42 d (4)). Complexes 1–4 as a part of ternary catalytic systems 1–4/TB, HNB/AlR 3 (AlR 3 = AliBu 3 , AliBu 2 H; TB = [Ph 3 C][B(C 6 F 5 ) 4 ], HNB = [PhNHMe 2 ][B(C 6 F 5 ) 4 ]) demonstrated high catalytic activity in isoprene polymerization and enable 80%–100% conversion of 1000 equivalents of monomer into polymer at 25 °C within 3–180 min. The isolated polyisoprenes feature predominantly cis -1,4-regularity (69.2%–87.3%) and polydispersities M w / M n = 2.26–8.92. Moreover, the binary (2/TB) and ternary (1–4/TB/10 AliBu 3 ) systems initiate 1-heptene polymerization providing 40%–100% conversion of 500 equivalents of monomer in 24 h at 25 °C giving polymer samples with M n = 1.55–190.2 × 10 3 and M w / M n = 1.55–3.87.
Type of Medium:
Online Resource
ISSN:
1477-9226
,
1477-9234
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2022
detail.hit.zdb_id:
1472887-4
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