Syntheses and X-ray structures of some pyrrolylaldiminate metal complexes

Liang, Lan‐Chang; Yang, Chih‐Wei; Chiang, Michael Y.; Hung, Chen‐Hsiung; Lee, Pei-Ying

doi:10.1016/s0022-328x(03)00555-2

Cited by 27 publications

(21 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…45 Unsurprisingly, the complex L 2 AlMe 2 shows a distorted-tetrahedral geometry (Figure 5), originating from a relatively acute N1− Al−N2 angle of 84.68(5)°of the pyrrolaldiminato ligand, which is comparable to those in complex 5-tert-butyl-2-[(2,6diisopropylphenyl)aldimino]pyrrole aluminum dimethyl (85.5(2)°) and its chloride precursor (88.2(2)°). 44 Also, the Al−C12(13) (1.966(2) and 1.951(2) Å) and Al−N1(2) bond lengths (1.981(2) and 1.911(2) Å) lie in the expected range. Finally, we examined the feasibility of conducting a reverse ligand exchange, meaning the displacement of a tetramethylaluminate moiety by such iminopyrrolyl ligands.…”

Section: ■ Introductionmentioning

confidence: 76%

“…43 Single crystals of Me 2 Al[2-(2,6-Me 2 C 6 H 3 NCH)C 4 H 3 N] (L 2 AlMe 2 ) were gained from concentrated n-hexane solutions at −40 °C. Several dimethylaluminum pyrrolylaldiminate complexes were previously structurally characterized, including 5-tert-butyl-2-[(2,6-diisopropylphenyl)aldimino]pyrrolyl 44 and 2,5-bis(N-aryliminomethyl)pyrrolyl derivatives. 45 Unsurprisingly, the complex L 2 AlMe 2 shows a distorted-tetrahedral geometry (Figure 5), originating from a relatively acute N1− Al−N2 angle of 84.68(5)°of the pyrrolaldiminato ligand, which is comparable to those in complex 5-tert-butyl-2-[(2,6diisopropylphenyl)aldimino]pyrrole aluminum dimethyl (85.5(2)°) and its chloride precursor (88.2(2)°).…”

Section: ■ Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis of Rare-Earth-Metal Iminopyrrolyl Complexes from Alkyl Precursors: Ln→Al N-Ancillary Ligand Transfer

et al. 2013

View full text Add to dashboard Cite

Protonolysis of [YMe3] n with 2-{(N-2,6-dialkylphenyl)iminomethyl)}pyrroles (alkyl = iPr (L1), Me (L2)) gave homoleptic iminopyrrolyl complexes YL1 3 and YL2 3 as well as the complex [L2YL2,Me]2 containing a dianionic pyrrolaldiminato ligand, formed via methylation of the imino backbone. Treatment of the half-sandwich complex [(C5Me5)YMe2]3 and yttrocene (C5Me5)2YMe(THF) with either 2 or 1 equiv of HL afforded the monomeric complexes (C5Me5)YL2 and (C5Me5)2YL,respectively. The complex (C5Me5)YL2 2 readily underwent Ln→Al iminopyrrolyl ligand transfer in the presence of trimethylaluminum, producing the known (C5Me5)Y(AlMe4)2. Salt metatheses of homoleptic Ln(AlMe4)3 (Ln = Y, La) with KL gave complicated reaction mixtures from which the η5/η1:κ1 pyrrolaldiminato-bridged complex [L1,MeLa(AlMe4)]2 and bis(tetramethylaluminate) complex L2Y(AlMe4)2 could be isolated and crystallographically characterized. Moreover, the solid-state structures of YL2 3, [L2YL2,Me]2, (C5Me5)YL1 2, (C5Me5)2YL1, and L2AlMe2 are presented.

show abstract

Section: ■ Introductionmentioning

confidence: 76%

Section: ■ Introductionmentioning

confidence: 99%

Synthesis of Rare-Earth-Metal Iminopyrrolyl Complexes from Alkyl Precursors: Ln→Al N-Ancillary Ligand Transfer

et al. 2013

View full text Add to dashboard Cite

show abstract

“…However, the use of these ligands in main‐group chemistry is less developed. The most widely studied main‐group aryliminopyrrolide complexes are based on aluminum . In particular, these Al‐complexes find usage as catalysts in lactide ring‐opening polymerization (ROP) and guanylation .…”

Section: Introductionmentioning

confidence: 99%

Hydrosilylation in Aryliminopyrrolide‐Substituted Silanes

Witteman

Evers

Zhan

et al. 2016

Chemistry A European J

View full text Add to dashboard Cite

A range of silanes was synthesized by the reaction of HSiCl3 with iminopyrrole derivatives in the presence of NEt3 . In certain cases, intramolecular hydrosilylation converts the imine ligand into an amino substituent. This reaction is inhibited by factors such as electron-donating substitution on Si and steric bulk. The monosubstituted ((Dipp) IMP)SiHMeCl ((Dipp) IMP=2-[N-(2,6-diisopropylphenyl)iminomethyl]pyrrolide), is stable towards hydrosilylation, but slow hydrosilylation is observed for ((Dipp) IMP)SiHCl2 . Reaction of two equivalents of (Dipp) IMPH with HSiCl3 results in the hydrosilylation product ((Dipp) AMP)((Dipp) IMP)SiCl ((Dipp) AMP=2-[N-(2,6-diisopropylphenyl)aminomethylene]pyrrolide), but the trisubsitituted ((Dipp) IMP)3 SiH is stable. Monitoring the hydrosilylation reaction of ((Dipp) IMP)SiHCl2 reveals a reactive pathway involving ligand redistribution reactions to form the disubstituted ((Dipp) AMP)((Dipp) IMP)SiCl as an intermediate. The reaction is strongly accelerated in the presence of chloride anions.

show abstract

“…1 H NMR (C 6 D 6 , 500 MHz) d 7.54 (dd, 4, Ar), 7.08 (d, 2, Ar), 7.02 (q, 3, Ar), 6.91 (m, 5, Ar), 6.74 (dd, 1, Ar), 6.40 (t, 1, Ar), 6.24 (m, 1, Ar), 2.11 (s, 6, ArCH 3 ), 1.42 (t, 6, AlCH 2 CH 3 ), 0.35 (q, 4, AlCH 2 CH 3 ). 13…”

Section: Synthesis Of 3amentioning

confidence: 99%

“…1 H NMR spectra are referenced using the residual solvent peak at d 7.16 for C 6 D 6 and d 7.27 for CDCl 3 13. C NMR spectra are referenced to the internal solvent peak at d 128.39 for C 6 D 6 and d 77.23 for CDCl 3 .…”

mentioning

confidence: 99%

Aluminium complexes of bidentate N,O- and N,N-ligands derived from oxidative functionalization of amido phosphines: synthesis, structure and reactivity

et al. 2010

Self Cite

View full text Add to dashboard Cite

A series of amido phosphinoxide and amido phosphinimine ligands that are electronic variations of monoanionic N,O- and N,N-ketiminates have been prepared and employed to examine the coordination chemistry of aluminium. Oxidation of the previously established N-(2-diphenylphosphinophenyl)-2,6-dialkylaniline in the presence of H(2)O(2) or organic azides RN(3) (R = 2,6-C(6)H(3)(i)Pr(2), SiMe(3)) led to phosphinoxides (H[NO] 1a-b) and phosphinimines (H[NN] 1c-d), respectively. Alkane elimination reactions of these protio-ligand precursors with trialkylaluminium in toluene or pentane solutions afforded cleanly the corresponding organoaluminium complexes, including dimethyl 2a-d, diethyl 3a-d and diisobutyl derivatives 4a-b and 4d. Solution NMR studies revealed Cs symmetry for these organoaluminium species, in which the α-hydrogen atoms are all diastereotopic. The correlation between the steric congestion of these molecules and the degree of resolution of the multiplet signals corresponding to the diastereotopic α-hydrogen atoms observed by the (1)H NMR spectroscopy is of particular interest. Dichloroaluminium complexes 5c-d were prepared in high yields by protonolysis of MeAlCl(2) with 1c-d. Single-crystal X-ray diffraction analyses of 2c-d, 3a, 3d, 4a, and 4d elucidated a mononuclear, distorted tetrahedral core for all of these aluminium species. Interestingly, complexes 2c-d are active initiators for catalytic ring-opening oligomerization of ε-caprolactone, whereas 2a-b are rather inactive, highlighting the significance of the steric hindrance imposed by the amido phosphinimine ligands, as compared to that imposed by the phosphinoxide counterparts.

show abstract

Syntheses and X-ray structures of some pyrrolylaldiminate metal complexes

Cited by 27 publications

References 28 publications

Synthesis of Rare-Earth-Metal Iminopyrrolyl Complexes from Alkyl Precursors: Ln→Al N-Ancillary Ligand Transfer

Synthesis of Rare-Earth-Metal Iminopyrrolyl Complexes from Alkyl Precursors: Ln→Al N-Ancillary Ligand Transfer

Hydrosilylation in Aryliminopyrrolide‐Substituted Silanes

Aluminium complexes of bidentate N,O- and N,N-ligands derived from oxidative functionalization of amido phosphines: synthesis, structure and reactivity

Contact Info

Product

Resources

About