Coordination Chemistry of {[Zr]−Cl−[Zr]}+ Complexes

Jacobsen, Heiko; Brackemeyer, Thomas; Berke, Heinz; Erker, Gerhard; Fröhlich, Roland

doi:10.1002/1099-0682(200007)2000:7<1423::aid-ejic1423>3.0.co;2-8

Cited by 9 publications

(4 citation statements)

References 25 publications

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“…On the other hand, as reported elsewhere for adducts of [(η 5 ‐Cp) 3 Zr][MeB(C 6 F 5 ) 3 ] with either Cp 2 ZrCl 2 or (η 5 ‐Cp) 3 ZrCl the Zr−Cl−Zr linkage is bent to varying degrees at Cl [38] …”

Section: Resultssupporting

confidence: 63%

“…2 kJ mol −1 for 2 ) the adoption of a linear vs. a bent geometry may have a steric component that is as important as any possible π‐character to the Zr−X bonds. We do note that the frontier molecular orbital (FMO) analogy between bent vs. linear AH 2 molecules and these structures, as proposed by Erker and co‐workers, [38] is not strictly applicable when both metallocene fragments are coordinately and electronically unsaturated.…”

Section: Resultsmentioning

confidence: 84%

“…[37] On the other hand, as reported elsewhere for adducts of [(η 5 -Cp) 3 Zr][MeB(C 6 F 5 ) 3 ] with either Cp 2 ZrCl 2 or (η 5 -Cp) 3 ZrCl the ZrÀ ClÀ Zr linkage is bent to varying degrees at Cl. [38] In this work we examined the structure of these complexes at the M06-2X/TZVP level of theory and determined two stable geometries for complexes 2, gauche and syn-periplanar, as shown in Scheme 3. We also examined the μ-F analog of complex 5 and determined that a linear anti geometry was adopted in both gas and condensed phase (see Supporting Information).…”

Section: Structure Of Dinuclear Ions 2 5 Andmentioning

confidence: 99%

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Activation of Substituted Metallocene Catalysts Using Methylaluminoxane

Collins

Linnolahti

2022

ChemCatChem

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Activation of the metallocene complexes (n-C 4 H 9 -(η 5 -C 5 H 4 )) 2 ZrCl 2 (BuCp 2 ZrCl 2 ) and rac-1,2-ethylenebis(1-η 5 -C 9 H 6 )ZrCl 2 (EBIZrCl 2 ) using methylaluminoxane (MAO) was investigated by electrospray ionization mass spectrometry (ESI-MS). Formation of dinuclear complexes at low Al : Zr ratios, which is accompanied by catalyst deactivation, occurs in the former case. In contrast, this behavior was not observed at similar Al : Zr ratios in the case of the EBIZrCl 2 complex. Both active [BuCp 2 ZrMe 2 AlMe 2 ][MAO(Me)] 3 and deactivated [(BuCp 2 Zr) 2 (μ-CH 2 )μ-Cl][MAO(Me)] 9 complexes were detected in leaching experiments using a SiO 2 -MAO-supported BuCp 2 ZrCl 2 catalyst and excess MAO. DFT studies of the structure and UV-Vis spectra calculated for the dinuclear cations 9 detected by ESI-MS suggest that these species may account for long-wavelength absorption seen in experimental spectra of complexes like BuCp 2 ZrCl 2 upon activation with MAO.

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Section: Resultssupporting

confidence: 63%

Section: Resultsmentioning

confidence: 84%

Section: Structure Of Dinuclear Ions 2 5 Andmentioning

confidence: 99%

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Activation of Substituted Metallocene Catalysts Using Methylaluminoxane

Collins

Linnolahti

2022

ChemCatChem

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“…Furthermore, so-called solid-state packing effects need to be considered. The authors argue that a “close look at the X-ray structure seems to exclude the possibility that the presence of the counterions (PF 6 – ) leads to a distortion of the allyl coordination geometry.” However, crystal effects are not always evident by close inspection alone; for the cation [CpClZrClZrCp 3 ] + , the negative charge field of its molecular environment in the crystal has a significant influence on the Zr–Cl distances, and the bent molecule t Bu 3 PCuOSiPh 3 (∠(Cu–O–Si) = 117° in the gas phase) undergoes linearization in the solid state due to intermolecular dispersive interactions . The capabilities and prospects of readily available atomistic simulation packages allow one to promote “crystal packing” from the status of deus ex machina to a quantifiable effect.…”

Section: Introductionmentioning

confidence: 99%

A Failure of DFT Is Not Necessarily a DFT Failure–Performance Dependencies on Model System Choices

Jacobsen¹

2011

J. Chem. Theory Comput.

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The claim that DFT does not provide an accurate description of a weak Ru-C interaction (J. Chem. Theory Comput.2007, 3, 665-670) is put into broader perspective. The mismatch between structures obtained from DFT (BP86) as well as DFT-D (BP86-D2) calculations of isolated molecules in the gas phase and geometries resulting from X-ray crystal structure determination is due to a dissatisfactory chemical model system. Intermolecular forces within the molecular surroundings of the crystal obtained from semiempirical lattice energy calculations emerge as likely candidates responsible for the incongruity of experimental results and computation.

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