Electronic interactions in 1-ethynyl-2-phenyltetramethyldisilanes HCCSiMe2SiMe2C6H4X

Shaw-Taberlet, Jennifer A.; Hamon, Jean‐René; Roisnel, Thiery; Lapinte, Claude; Flock, Michaela; Mitterfellner, Thomas; Stueger, Harald

doi:10.1016/j.jorganchem.2007.01.024

Cited by 3 publications

(8 citation statements)

References 35 publications

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“…The geometry around the silicon atoms is almost tetrahedral, and the C37–C38–Si1 angle deviates only slightly from linearity (Table ). The nearly planar Si–C 6 H 4 –N(CH 3 ) 2 moiety constitutes a remarkable feature of 1c , which was also noted for the free ligand …”

Section: Resultsmentioning

confidence: 55%

“…The 31 P NMR spectroscopic shift of 1a – e is almost independent of the substituents attached to the aromatic ring. The 13 C chemical shifts of the acetylene carbon atoms of the organic precursors 6a – e were found to be nearly unaffected by the electronic properties of the substituents X on the phenyl ring . In contrast, in the case of complexes 1a – e , the 13 C NMR chemical shifts of the α‐carbon of the acetylide ligand slightly vary with the nature of the substituents, while the chemical shifts of the β‐carbon are almost independent of the nature of X.…”

Section: Resultsmentioning

confidence: 89%

“…0.03 Å) and Si2–C39 (ca. 0.008 Å) bonds . Notably, the Si–Si bond length, which ranges from 2.3393(8) Å in 1a to 2.3461(13) Å in 1e , is somewhat longer than that in the binuclear complexes [Cp*(dppe)Fe–C≡C–{Si(CH 3 ) 2 } 2 –C≡C–Fe(dppe)Cp*] [ d Si–Si = 2.3332(18) Å].…”

Section: Resultsmentioning

confidence: 98%

“…In contrast, the bromo‐substituted complex 1e exhibits the unusual gauche array [C38–Si1–Si2–C39 = 55.42(16)]. Theoretical calculations previously performed for the free ligand 2c [X = N(CH 3 ) 2 ] have suggested that the gauche conformation could be favored by the packing, rather than by electronic effects . The small rotational barriers and the negligible energy difference between the gauche and the anti form have indicated nearly unhindered rotation around the Si–Si bond and equal populations of both rotamers in the gas phase at room temperature .…”

Section: Resultsmentioning

confidence: 99%

“…While the original synthetic access to substituted 1‐ethynyl‐2‐phenyltetramethyldisilanes HC≡C–[Si(CH 3 ) 2 ] 2 –1,4‐C 6 H 4 X { 6a : X = H; 6b : X = CH 3 ; 6c : X = N(CH 3 ) 2 ; 6d : X = CF 3 ; 6e : X = Br} has previously been described, we now report the synthesis of the organoiron family [Cp*(dppe)Fe–C≡C–{Si(CH 3 ) 2 } 2 –C 6 H 4 X] ( 1a – e ) and their characterization. We also report on the preparation and isolation of the oxidized iron(III) counterparts [ 1a – e ](PF 6 ), and discuss the transmission of the electronic effect of the X substituents to the metal across the carbon–silicon hybrid bonding.…”

Section: Introductionmentioning

confidence: 99%

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Electronic Interactions in the Electroactive Iron σ‐Ethynyl‐2‐Phenyltetramethyldisilanes [Cp*(dppe)Fe–C≡C–{Si(CH₃)₂}₂–1,4‐C₆H₄X](PF₆)_n (n = 0, 1)

et al. 2017

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Treatment of the triflate complex [Cp*(dppe)FeOTf ] {5; Cp* = η 5 -C 5 (CH 3 ) 5 , dppe = 1,2-bis(diphenylphosphanyl)ethane, OTf = CF 3 SO 3 } with an excess of HC≡C-[Si(CH 3 ) 2 ] 2 -1,4-C 6 H 4 X (6a-e) in a mixture of THF and triethylamine (NEt 3 ) provides the new complexes {1a: X = H; 1b: X = CH 3 ; 1c: X = N(CH 3 ) 2 ; 1d: X = CF 3 ; 1e: X = Br}, which were isolated in 64 to 81 % yields as orange powders. The cyclic voltammetry, and multinuclear NMR, IR, and UV/Vis spectroscopic data obtained for 1a-e, as well as the X-ray crystal structures determined for 1a, 1c, and 1e, reveal the importance of the σ-π conjugation (hyperconjugation) between the Si-Si σ-bond and the vicinal C≡C π-orbitals in the description of the electronic structure of [a] 1364 the ground state of these complexes. When compounds 1a-e are reacted with [(C 5 H 5 ) 2 Fe](PF 6 ) (1 equiv.) at 20°C, they provide [1a-e](PF 6 ), which partially decompose in solution during the reaction process. They were isolated as mixtures with the mononuclear [Cp*(dppe)Fe=C=CH 2 ](PF 6 ) (7) and binuclear [Cp*(dppe)Fe=C=CH-CH=C=Fe(dppe)Cp*](PF 6 ) 2 (8) vinylidenes. Reduction of these mixtures with cobaltocene affords the parent neutral compounds 1a-e in analytically pure forms. The iron(III) complexes were characterized by IR and Mössbauer spectroscopy, which clearly showed that the iron(III) nucleus sensed the electronic effect of the X substituents.

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Section: Resultsmentioning

confidence: 55%

Section: Resultsmentioning

confidence: 89%

Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Electronic Interactions in the Electroactive Iron σ‐Ethynyl‐2‐Phenyltetramethyldisilanes [Cp*(dppe)Fe–C≡C–{Si(CH₃)₂}₂–1,4‐C₆H₄X](PF₆)_n (n = 0, 1)

et al. 2017

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Redox-Active Organometallics: Magnetic and Electronic Couplings through Carbon−Silicon Hybrid Molecular Connectors

Hamon

Justaud²,

Cador³

et al. 2008

J. Am. Chem. Soc.

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Treatment of the triflate complex Cp*(dppe)FeOTf [12; Cp* = eta(5)-C(5)(CH(3))(5), dppe = 1,2-bis(diphenylphosphino)ethane, OTf = CF(3)SO(3)] with an excess of HC[triple bond]C-(Si(CH(3))(2))(x)-C[triple bond]CH (x = 2-4) in diethyl ether provides the binuclear bis(vinylidene) derivatives [Cp*(dppe)Fe=C=CH(Si(CH(3))(2))(x)CH=C=Fe(dppe)Cp*][OTf](2) (x = 2, 13; x = 3, 14; x = 4, 15), which were isolated as ochre solids and rapidly characterized by FT-IR, (1)H, (31)P, and (13)C NMR spectroscopies. The complexes 13-15 were reacted with potassium tert-butoxide to afford the bis(alkynediyl) complexes [Cp*(dppe)Fe-C[triple bond]C(Si(CH(3))(2))(x)C[triple bond]C-Fe(dppe)Cp*] (x = 2, 1; x = 3, 2; x = 4, 3), which were isolated as orange powders in yields ranging from 76 to 91%. The IR, cyclic voltammetry, and UV-vis data obtained for 1-3 and the X-ray crystal structures determined for 1 and 3 reveal the importance of the sigma-pi conjugation (hyperconjugation) between the Si-Si sigma bond and the adjacent C[triple bond]C pi-symmetric orbitals in the description of the electronic structure of the ground state of these complexes. When reacted at low temperature with 2 equiv of [(C(5)H(5))(2)Fe]X or AgX [X = BPh(4), B(3,5-(CF(3))(2)C(6)H(3))(4))], compounds 1-3 provide 1[X](2), 2[X](2), and 3[X](2), which can be isolated and stored below -20 degrees C. EPR spectroscopy and magnetization measurements established that the superexchange interaction propagates through the Si-Si bonds (J = -0.97(2) cm(-1) for 3[X](2)). UV-vis-near-IR spectra were obtained with an optically transparent thin-layer electrosynthetic (OTTLE) cell for 1-3[OTf](n) (n = 0-2). A band with a maximum that increases from 6400 cm(-1) (1[OTf]) to 8500 cm(-1) (3[OTf]) observed for the mixed-valence species was ascribed to intervalence charge transfer evidencing photodriven electron transfer through the carbon-silicon hybrid connectors with H(ab) parameters ranging from 64 to 285 cm(-1).

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Photoinduced Brook-Type Rearrangement of Acylcyclopolysilanes

et al. 2013

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Previously unknown 1,1,4-tris(trimethylsilyl)-4-acyldodecamethylcyclohexasilanes (Me3Si)2Si6Me12(Me3Si)COR (16a, R = tert-butyl; 16b, R = 1-adamantyl) have been synthesized by the reaction of the potassium silanides (Me3Si)2Si6Me12(Me3Si)K with acid chlorides ClCOR, and their photochemical rearrangement reactions have been studied. The molecular structures of 16a,b as determined by single-crystal X-ray diffraction analysis exhibit an unusual twist-boat conformation of the cyclohexasilane ring. When 16a,b were photolyzed with λ >300 nm radiation, they underwent Brook type 1,3-Si → O migration reactions to generate the cyclohexasilanes 17a,b with exocyclic Si=C bonds along with smaller amounts of the ring-enlarged species 19a,b with endocyclic Si=C double bonds. While 17a,b were stable enough to allow characterization by NMR and UV absorption spectroscopy, the less stable products 19a,b could only be observed in the form of their methanol adducts.

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Electronic interactions in 1-ethynyl-2-phenyltetramethyldisilanes HCCSiMe2SiMe2C6H4X

Cited by 3 publications

References 35 publications

Electronic Interactions in the Electroactive Iron σ‐Ethynyl‐2‐Phenyltetramethyldisilanes [Cp*(dppe)Fe–C≡C–{Si(CH₃)₂}₂–1,4‐C₆H₄X](PF₆)_n (n = 0, 1)

Electronic Interactions in the Electroactive Iron σ‐Ethynyl‐2‐Phenyltetramethyldisilanes [Cp*(dppe)Fe–C≡C–{Si(CH₃)₂}₂–1,4‐C₆H₄X](PF₆)_n (n = 0, 1)

Redox-Active Organometallics: Magnetic and Electronic Couplings through Carbon−Silicon Hybrid Molecular Connectors

Photoinduced Brook-Type Rearrangement of Acylcyclopolysilanes

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Electronic interactions in 1-ethynyl-2-phenyltetramethyldisilanes HCCSiMe2SiMe2C6H4X

Cited by 3 publications

References 35 publications

Electronic Interactions in the Electroactive Iron σ‐Ethynyl‐2‐Phenyltetramethyldisilanes [Cp*(dppe)Fe–C≡C–{Si(CH3)2}2–1,4‐C6H4X](PF6)n (n = 0, 1)

Electronic Interactions in the Electroactive Iron σ‐Ethynyl‐2‐Phenyltetramethyldisilanes [Cp*(dppe)Fe–C≡C–{Si(CH3)2}2–1,4‐C6H4X](PF6)n (n = 0, 1)

Redox-Active Organometallics: Magnetic and Electronic Couplings through Carbon−Silicon Hybrid Molecular Connectors

Photoinduced Brook-Type Rearrangement of Acylcyclopolysilanes

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Product

Resources

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Electronic Interactions in the Electroactive Iron σ‐Ethynyl‐2‐Phenyltetramethyldisilanes [Cp*(dppe)Fe–C≡C–{Si(CH₃)₂}₂–1,4‐C₆H₄X](PF₆)_n (n = 0, 1)

Electronic Interactions in the Electroactive Iron σ‐Ethynyl‐2‐Phenyltetramethyldisilanes [Cp*(dppe)Fe–C≡C–{Si(CH₃)₂}₂–1,4‐C₆H₄X](PF₆)_n (n = 0, 1)