Ancillary Ligand Effects in Organoyttrium Chemistry: Synthesis, Characterization, and Electronic Structure of Bis(benzamidinato)yttrium Compounds
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The synthesis of [PhC(NSiMe 3 ) 2 ] 2 Y(μ-Cl) 2 Li·2THF ( 1 ) from YCl 3 ·3.5THF and [PhC(NSiMe 3 ) 2 ]Li, which is easily transformed into [PhC(NSiMe 3 ) 2 ] 2 YCl·THF ( 2 ), provides a useful entry into the chemistry of several bis( N, N ‘-bis(trimethylsilyl)benzamidinato)yttrium complexes. Those prepared from 2 by chloride metathesis include [PhC(NSiMe 3 ) 2 ] 2 YR (R = BH 4 ·THF ( 3 ), N(SiMe 3 ) 2 ( 4 ), 2,6-(CMe 3 ) 2 -4-MeOC 6 H 2 ( 5 ), (μ-Me) 2 Li·TMEDA ( 6 ) (TMEDA = N, N, N ‘, N ‘-tetramethylethylenediamine), CH 2 Ph·THF ( 7 ), CH(SiMe 3 ) 2 ( 8 )). Similar to 8, [ p -MeOC 6 H 4 C(NSiMe 3 ) 2 ] 2 YCH(SiMe 3 ) 2 ( 8 OMe ) could be prepared starting from [ p -MeOC 6 H 4 C(NSiMe 3 ) 2 ] 2 YCl·THF ( 2 OMe ). Hydrogenolysis (4 atm) of 8 and 8 OMe affords dimeric hydrides {[ p -X-C 6 H 4 C(NSiMe 3 ) 2 ] 2 Y(μ-H)} 2 (X = H ( 9 ), X = MeO ( 9 OMe )). The alkyl 8 OMe and the hydride 9 have been characterized by an X-ray diffraction structure determination. Sterically the bis( N, N ‘-bis(trimethylsilyl)benzamidinate) ligand system resembles more the bis(pentamethylcyclopentadienyl) than the bis(cyclopentadienyl) ligand set. However, INDO/1 semi-empirical MO studies indicate that the electronic properties of [HC(NH) 2 ] 2 YCH 3 (used as a model for bis(benzamidinato)yttrium alkyl complexes) are rather different from [C 5 H 5 ] 2 YCH 3 . The yttrium atom in [HC(NH) 2 ] 2 YCH 3 is considerably more positively charged than in [C 5 H 5 ] 2 YCH 3 . The resulting strong ionic character of the bis(benzamidinate) system is held responsible for the absence of agostic interactions and H/D exchange and the low hydrogenolysis rate observed.
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The amidinate ligand bears a stronger negative charge than cyclopentadienyl fragments, generating a more Lewis acidic metal center that benefits ethylene polymerization.
“Compared with the widely employed cyclopentadienyl fragments, the amidinate ligand bears a much stronger negative charge to generate a more Lewis acidic metal center,53 which benefits E polymerization.”
From Installing a Trigger to Upcycle High-Density Polyethylene (2024) · cites this paper as [53]
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Installing a Trigger to Upcycle High-Density Polyethylene
Nan, T., Chen, Q., Zheng, Z., Liang, Y., Qin, Y., Wang, Y., Liu, B., & Cui, D. (2024) · Journal of the American Chemical Society · doi:10.1021/jacs.4c08958 · Cited by 42 · see citing works
- Authors
- Duchateau, R., van Wee, C. T., Meetsma, A., van Duijnen, P. T., & Teuben, J. H.
- Affiliations
- University of Groningen (NL)
- Groningen Center for Catalysis and Synthesis, Department of Chemistry, University of Groningen, Nijenborgh 4, NL-9747 AG Groningen, The Netherlands
- ORCID
- Duchateau, Robbert
- Venue
- Organometallics
- Publisher
- American Chemical Society (ACS)
- Published
- 1996-04-30
- Volume
- 15
- Issue
- 9
- Pages
- 2279-2290
- ISSN
- 0276-7333 (ISSN-L)
- 1520-6041
- OpenAlex
- W2157879998
- Cited by
- 164
- References
- 96
- Citations by year
- 2026: 1 · 2025: 2 · 2024: 1 · 2023: 2 · 2021: 3 · 2020: 3 · 2019: 2 · 2018: 1 · 2017: 2 · 2016: 3 · 2015: 3 · 2014: 4 · 2013: 8 · 2012: 7
- FWCI
- 11.09
- Type
- journal article
- Language
- en
- Open access
- green
- research.rug.nl
- Licence
- other-oa
- Locations
- Organometallics (publishedVersion)
- University of Groningen research database (University of Groningen / Centre for Information Technology) (publishedVersion, other-oa)
- University of Groningen research database (University of Groningen / Centre for Information Technology) (submittedVersion)
- University of Groningen research database (University of Groningen / Centre for Information Technology) (submittedVersion, other-oa)
- Topics
- Physical Sciences › Chemistry › Organic Chemistry › Coordination Chemistry and Organometallics
- Physical Sciences › Chemistry › Inorganic Chemistry › Synthesis and characterization of novel inorganic/organometallic compounds
- Physical Sciences › Chemistry › Organic Chemistry › Organometallic Complex Synthesis and Catalysis
- Keywords
- ancillary ligand effects, hydrogenolysis, electronic structure, ligand field parameters
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