Synthesis, structure characterization and catalytic activity of lanthanide complexes containing an <i>ansa</i> carbonous‐bridged cyclopentadienyl—thienyl ligand

Xie, Xiaomin; Huang, Jiling

doi:10.1002/aoc.1449

Cited by 6 publications

(3 citation statements)

References 24 publications

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“…[66] Unless otherwise noted, solvents and reagents were purchased from Sigma-Aldrich, Fisher Scientific or Alfa Aesar. B 2 Cl 2 Mes 2 , [67] 2thienyllithium, [68] and magnesium anthracene, [Mg(C 14 H 10 )(THF) 3 ], [69] were synthesized by following literature procedures. Refer to the Supporting Information for atom numbering systems.…”

Section: Methodsmentioning

confidence: 99%

Thienyl‐Substituted Diboranes(4): Electronic Stabilization of Radicals Versus Increased Reactivity towards Bond Activation

Schorr

Keim

Arrowsmith

et al. 2023

Chemistry A European J

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Low‐valent main group chemistry involves a balancing act between steric and electronic stabilization of the electron‐rich low oxidation state main group centers and their desired reactivity. Herein we show that the combination of sterically shielding mesityl and rotationally flexible 2‐thienyl groups, the latter having the potential to be either electronically stabilizing or activating, at a diborane(4) provides a platform for both radical anion stabilization and unusual bond activation and rearrangement reactions. The addition of a Lewis base to a 1,2‐dimesityl‐1,2‐dithienyldiborane(4) (1) results in direct and unprecedented C−H borylation of one thienyl substituent with cleavage of the B−B bond. The facile one‐electron reduction of 1 yields a stable diboron radical anion through delocalization of its unpaired electron over the entire planar 1,2‐dithienyldiboron framework, as evidenced by EPR spectroscopy and DFT calculations. The two‐electron reduction of 1 with magnesium anthracene under more forcing conditions results in B−B bond cleavage and replacement of one thienyl sulfur atom by a mesitylboron moiety, leading to the formation of a magnesium complex of an η5‐diborafulvene dianion. Salt metathesis of the latter with [(η6‐p‐cymene)RuCl2] affords a mixed ruthenium sandwich complex of an η5‐borylborole dianion. Calculations highlight both the structural and electronic changes in the boron‐substituted heterocyclic C4B dianion upon switching coordination from magnesium (diborafulvene dianion) to ruthenium (borylborole dianion).

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Section: Methodsmentioning

confidence: 99%

Thienyl‐Substituted Diboranes(4): Electronic Stabilization of Radicals Versus Increased Reactivity towards Bond Activation

Schorr

Keim

Arrowsmith

et al. 2023

Chemistry A European J

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“…Polymerization‐grade ethylene was directly used without further purification. (MeCp)TiCl 3 , ( n BuCp)ZrCl 3 ·DME, 2‐thienyl lithium and substituted fulvenes were prepared by the literature procedures. All other chemicals were commercially available and used as received.…”

Section: Methodsmentioning

confidence: 99%

Ethylene polymerization with long‐lifetime monopendant thienyl‐substituted group 4 metallocenes

Xiao

et al. 2014

Applied Organom Chemis

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A series of group 4 metallocenes (RCp)[Cp-(bridge)-(2-C 4 H 3 S)]MCl 2 [M = Ti (C1-C4); M = Zr (C5-C8)] bearing a pendant thiophene group on a cyclopentadienyl ring have been synthesized, characterized and tested as catalyst precursors for ethylene polymerization. The molecular structures of representative titanocenes C2 and C4 were confirmed by single-crystal X-ray diffraction and revealed that both complexes exist in an expected coordination environment for a monomeric bent metallocene. No intramolecular coordination between the thiophene group and the titanium center could be observed in the solid state. Upon activation by methylaluminoxane (MAO), titanocenes C1-C4 showed moderate catalytic activities and produced high-or ultra-high-molecular-weight polyethylene (M v 70.5-227.1 × 10 4 g mol À1 ). Titanocene C3 is more active and long-lived, with a lifetime of nearly 9 h at 30°C. At elevated temperatures of 80-110°C, zirconocenes C5-C8 displayed high catalytic activities (up to 27.6 × 10 5 g PE (mol Zr) À1 h À1 ), giving high-molecular-weight polyethylene (M v 11.2-53.7 × 10 4 g mol À1 ). Even at 80°C, a long lifetime of at least 2 h was observed for the C8/MAO catalyst system.

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“…Elemental analyses were performed with a VARIO EL III analyzer. The cyclopentadienes (C 4 H 3 S)C(R 1 R 2 )C 5 H 5 (R 1 , R 2 = CH 3 (1); R 1 , R 2 = (CH 2 ) 5 (2); R 1 , R 2 = C 2 H 5 (3)) were prepared according to the published method [9].…”

Section: Methodsmentioning

confidence: 99%

Cyclopentadienyl diruthenium metal carbonyl complexes bearing pendant thienyl ligands

Liu

Tian

et al. 2010

Transition Met Chem

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Reactions of the thienyl side chain functionalized cyclopentadienyls (C 4 H 3 S)C(R 1 R 2 )C 5 H 5 [R 1 , R 2 = CH 3 (1); R 1 , R 2 = (CH 2 ) 5 (2); R 1 , R 2 = C 2 H 5 (3)] with Ru 3 (CO) 12 in refluxing xylene gave the corresponding cyclopentadienyl diruthenium carbonyl complexes [(g 5 -C 4 H 3 S)CR 1 R 2 (C 5 H 4 )-Ru(CO) 2 ] 2 (R 1 , R 2 = CH 3 (4); R 1 , R 2 = (CH 2 ) 5 (5); R 1 , R 2 = C 2 H 5 (6)), which were characterized by elemental analysis, IR and 1 H NMR spectra. The molecular structures of 4, 5 and 6 were determined by single crystal X-ray diffraction.

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Synthesis, structure characterization and catalytic activity of lanthanide complexes containing an ansa carbonous‐bridged cyclopentadienyl—thienyl ligand

Cited by 6 publications

References 24 publications

Thienyl‐Substituted Diboranes(4): Electronic Stabilization of Radicals Versus Increased Reactivity towards Bond Activation

Thienyl‐Substituted Diboranes(4): Electronic Stabilization of Radicals Versus Increased Reactivity towards Bond Activation

Ethylene polymerization with long‐lifetime monopendant thienyl‐substituted group 4 metallocenes

Cyclopentadienyl diruthenium metal carbonyl complexes bearing pendant thienyl ligands

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