Mono(pentamethylcyclopentadienyl)thorium Chemistry:  Synthesis, Structural Characterization, and Reactivity of Aryloxide and Alkyl Derivatives

Butcher, Raymond J.; Clark, David L.; Grumbine, Steven K.; Scott, Brian L.; Watkin, John G.

doi:10.1021/om9508694

Cited by 36 publications

(31 citation statements)

References 53 publications

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“… 45 – 52 The Th(1)–N(7) distance of 2.469(2) Å is noticeably shorter than that typically observed for a dative Th–N bond, 53 – 56 while the Th(1)–C(29) bond length of 2.529(3) Å is in the range observed for other σ-bonded alkyl moieties. 14 , 19 , 57 This insertion differs from that observed by Andersen and co-workers in their Th( C H 2 SiMe 2 N SiMe 3 )(NR 2 ) 2 (where R = SiMe 3 ) complex, which undergoes insertion of tert -butyl isocyanide into the C–Si bond of the metallacycle to produce Th[( t Bu) N C(CH 2 )SiMe 2 N SiMe 3 ](NR 2 ) 2 . 58 Similar reactivity was observed with CO in Andersen's system, resulting in Th[( O C( CH 2 )SiMe 2 N SiMe 3 )](NR 2 ) 2 .…”

Section: Resultsmentioning

confidence: 72%

Insertion, protonolysis and photolysis reactivity of a thorium monoalkyl amidinate complex

Settineri

Arnold

2018

Chem. Sci.

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Section: Resultsmentioning

confidence: 72%

Insertion, protonolysis and photolysis reactivity of a thorium monoalkyl amidinate complex

Settineri

Arnold

2018

Chem. Sci.

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“…Similar increases in M-C-Si or M-C-C (M ) Th or U) bond angles have been observed in other trimethylsilylmethyl or neopentyl complexes and are attributed to R-agostic C-H-Th interactions. 13,23,[48][49][50] Further evidence for the presence of agostic interactions is provided by a 1 J C,H of 102 Hz for the rapidly exchanging CH 2 SiMe 3 groups in the 1 H-coupled 13 and 98 Hz in [(2,6-tBu 2 H 3 C 6 O) 2 ThR 2 ] 13 (R ) CH 2 SiMe 3 ). A 1 J C,H value of 103 Hz is observed for the CH 2 SiMe 3 groups in 7 (60°C, C 7 D 8 ).…”

Section: Resultsmentioning

confidence: 99%

Extremely Stable Thorium(IV) Dialkyl Complexes Supported by Rigid Tridentate 4,5-Bis(anilido)xanthene and 2,6-Bis(anilidomethyl)pyridine Ligands

et al. 2007

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A new NON-donor ligand, 4,5-bis(2,6-diisopropylanilino)-2,7-di-tert-butyl-9,9-dimethylxanthene (H 2 -[XA 2 ], 1), was prepared by palladium-catalyzed coupling of 2,6-diisopropylaniline with the appropriate dibromoxanthene precursor. Stable K 2 (dme) 2 [XA 2 ] (2) and Na 2 [XA 2 ] (3) salts were accessible by deprotonation of H 2 [XA 2 ] with KH in dme or NaH in toluene. The thermally unstable lithium salt of McConville's 2,6-bis(2,6-diisopropylanilidomethyl)pyridine ligand (Li 2 [BDPP], 4) was isolated by deprotonation with nBuLi or LiCH 2 SiMe 3 in hexanes at low temperature. Reaction of [ThCl 4 (dme) 2 ] with Li 2 [BDPP] or M 2 (dme) n [XA 2 ] resulted in the formation of pentagonal bipyramidal [LThCl 2 (dme)] complexes (L ) BDPP, 5; XA 2 , 6). Subsequent reaction of 5 or 6 with LiCH 2 SiMe 3 gave base-and salt-free dialkyl complexes, [LTh(CH 2 SiMe 3 ) 2 ] (L ) BDPP, 7; XA 2 , 8), which are stable for days in solution at 90 and 70°C, respectively. Complexes 5, 7, and 8 were also accessible by initial combination of 2 or 4 equiv of LiCH 2 SiMe 3 with [ThCl 4 (dme) 2 ], followed by addition of H 2 L. These reactions likely proceed by alkane elimination, but dialkyl or tetraalkyl thorium intermediates were not identified. The X-ray crystal structure of 8 suggests the presence of R-agostic C-H-Th interactions for both alkyl groups. In solution, 7 and 8 exhibit temperature-dependent 1 J C,H coupling constants for ThCH 2 , demonstrating the presence of R-agostic interactions which become increasingly favored at lower temperature. Reaction of 5 with Li 2 [BDPP] at 0°C or 7 with H 2 [BDPP] at 100°C resulted in the formation of extremely sterically encumbered [Th(BDPP) 2 ] (9), which adopts a highly distorted six-coordinate geometry with the four anilido groups arranged in an approximate tetrahedron around thorium. Bisligand complexes were not accessible with the XA 2 platform, presumably due to increased ligand rigidity.

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“…In addition, although such interactions are often characterized by unusually low m C-H stretching vibrations in the IR spectrum, 70 no such peaks were observed for 6. There were also no low m C-H stretching vibrations observed for Cp*Th(OAr)[CH 2 Si(CH 3 ) 3 ] 2 (Ar = 2,6-t-Bu 2 C 6 H 3 ) 68 and Cp* 2 Th[CH 2 C(CH 3 ) 3 ] 2 , 67 for which the presence of a-agostic interactions were suggested from the 1 H NMR and structural data.…”

Section: Synthesis Characterization and Structural Determination Of {[mentioning

confidence: 93%

Synthesis and structure of diamido ether uranium(iv) and thorium(iv) halide “ate” complexes and their conversion to salt-free bis(alkyl) complexes

et al. 2005

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The high-yield synthesis, spectroscopic and structural determination of three new uranium(IV) and thorium(IV)ate complexes supported by three different diamido ether ligands are reported. The reaction of Li2[2,6-iPr2PhN(CH2CH2)]2O (Li2[DIPPNCOCN]) with 1 equiv. of UCl4 in THF generates [DIPPNCOCN]UCl3Li(THF)2(1), while reaction in toluene/ether gives salt-free [DIPPNCOCN]UCl2.1/2C7H8(2), which was identified by paramagnetically shifted 1H NMR. Reaction of 0.5 equiv. of {[tBuNON]UCl2}2([tBuNON]=[(CH3)3CN(Si(CH3)2)]2O2-) with 3.5 equiv. LiI in toluene and a minimal amount of THF results in [tBuNON]UI3Li(THF)2(3) and is very similar in structure to 1. {[MesNON]ThCl3Li(THF)}2(4), a dimeric complex with a Th2Li2Cl6 core, is prepared by reaction of Li2[2,4,6-Me3PhN(Si(CH3)2)]2O (Li2[MesNON]) with ThCl4 in THF. The analogous reaction in toluene did not yield the salt-free complex but rather a sterically crowded diligated compound, [MesNON]2Th (5), which was also structurally characterized. Complex 5 was prepared rationally by reacting 2 equiv. Li2[MesNON] with ThCl4 in toluene. The reaction of 1 and 3 with 2 equiv. of LiCH2Si(CH3)3 generates the stable, salt-free organoactinides [DIPPNCOCN]U(CH2Si(CH3)3)2(6) and [tBuNON]U(CH2Si(CH3)3)2(7). Complex 6 was structurally characterized. These reactions illustrate the viability of ate complexes as useful synthetic precursors.

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Mono(pentamethylcyclopentadienyl)thorium Chemistry: Synthesis, Structural Characterization, and Reactivity of Aryloxide and Alkyl Derivatives

Cited by 36 publications

References 53 publications

Insertion, protonolysis and photolysis reactivity of a thorium monoalkyl amidinate complex

Insertion, protonolysis and photolysis reactivity of a thorium monoalkyl amidinate complex

Extremely Stable Thorium(IV) Dialkyl Complexes Supported by Rigid Tridentate 4,5-Bis(anilido)xanthene and 2,6-Bis(anilidomethyl)pyridine Ligands

Synthesis and structure of diamido ether uranium(iv) and thorium(iv) halide “ate” complexes and their conversion to salt-free bis(alkyl) complexes

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