Synthesis, Structural Characterization, and Reactivity of Lanthanide Complexes Containing a New Methylene-Bridged Indenyl−Pyrrolyl Dianionic Ligand

Abstract

A new methylene-bridged ligand incorporating both indenyl and pyrrolyl moieties, (C 9 H 7 )CH 2 (R-C 4 H 3 -NH) (1), was prepared. Reaction of LnI 2 with 1 equiv of [(C 9 H 6 )CH 2 (R-C 4 H 3 N)]Li 2 (THF) x in THF, followed by recrystallization in DME, gave the organolanthanide(II) complexes (THF) x under the same conditions generated [(η 5 -C 9 H 6 )CH 2 (µ-η 1 :η 3 -C 4 H 3 N)Er(µ 3 -Cl)(µ-Cl)Li(THF) 2 ] 2 (5). Reaction of 4 with 2 equiv of n-butyllithium ( n BuLi) and subsequently with N,N′dicyclohexylcarbodiimide (CyNdCdNCy) gave the carbodiimide insertion into the Sm-C bond product 6), while treatment of 4 with 2 equiv of NaN-(SiMe 3 ) 2 in THF followed by reacting with CyNdCdNCy gave the carbodiimide insertion into the Sm-N bond product 7). These complexes were characterized by IR and 1 H NMR spectra and elemental analyses. Furthermore, the structures of all these compounds were also confirmed by X-ray diffraction analyses.

Differences in the cyclometalation reactivity of bisphosphinimine-supported organo-rare earth complexes

“…46,47 As a result, the development of new ancillary ligands to support stoichiometric and catalytic transformations at rare earth metal centres is an important and intensively studied area of organolanthanide chemistry. 31,45,47,48 To this end, we have recently reported a variety of carbazole-based bisphosphinimine frameworks for supporting complexes of Sc, Y and Lu (Chart 1, HL A ). [49][50][51][52][53] These ligands can be attached to rare earth metal centres via either an alkane elimination route or by a salt metathesis pathway.…”

Synthesis of pyrrole‐bridged constrained geometry complexes and their application for olefin polymerization

“…The complex 5 and 6 were prepared by the procedure according to the method by Zhou . The 1 H‐NMR and 13 C‐NMR spectrum of 5 was given in Supporting Information Figure S3 and S4.…”

Synthesis and structural characterization of (CH2)n-bridged indenyl-pyrazoles and their cyclopentadienyl nickel(II) complexes

“…The filtrate was evaporated all the volatiles under reduced pressure and the resulting crude 3-(3-bromopropyl)indenyl-2,4-dione (15 0 ) was further dried in vacuum at 100°C for 5 h and followed by reacting with hydrazine in refluxing ethanol (50 mL) for 2 h. After cooled and concentrated in vacuo the resultant viscous oil was purified by flash silica gel column chromatography with petroleum ether (60-90°C)/ethyl acetate/Et 3 N, v/v 4:4:1) as the eluent to give the product. 4-(3-(1H-Inden-3-yl)propyl)-3,5-dimethyl-1H-pyrazole (16). Alkylation of acetoacetone (2.00 g, 56.7 mmol) with 15 (4.23 g, 17.8 mmol) in the presence of K 2 CO 3 (2.76 g, 20.0 mmol) and KI (1.48 g, 8.9 mmol) produced 15 0 as a colorless oil which was directly reacted with hydrazine hydrate (85%, 3.0 mL, 50.9 mmol) in refluxing ethanol (50 mL) to afford 16 as a white solid (2.33 g, 52%).…”

“…Metal complexes of side chain-functionalized cyclopentadienyl ligands have been paid considerable attention over the past decade. ansa-Carbon-bridged cyclopentadienyl ligands have been well documented due to the dramatic effect of an incorporated ansa-brigde on the stability of their transition metal and lanthanide complexes [14][15][16]. N-Donor side chainfunctionalized indenyl ligands of type A (Chart 1) have also been paid attention in coordination chemistry.…”

“…N-Donor side chainfunctionalized indenyl ligands of type A (Chart 1) have also been paid attention in coordination chemistry. ansa-Bridged indenylamido complexes of titanium and niobium [17] and CH 2 -bridged pyrrolyl-indenyl complexes of lanthanides Sm, Yb and Eu [16] were reported. NR 2 -containing side chain-functionalized indenyl complexes of lanthanides Yb and Eu have demonstrated novel chemistry [18][19][20].…”