Cationic and neutral transition metal complexes with a tetramethylfulvene or trimethylallyldiene ligand

The acid-base reaction between Y(CH(2)SiMe(3))(3)(thf)(2) and the pyridyl-functionalized cyclopentadienyl (Cp) ligand C(5)Me(4)H-C(5)H(4)N (1 equiv) at 0 °C afforded a mixture of two products: (η(5):κ-C(5)Me(4)-C(5)H(4)N)Y(CH(2)SiMe(3))(2)(thf) (1 a) and (η(5):κ-C(5)Me(4)-C(5)H(4)N)(2)YCH(2)SiMe(3) (1 b), in a 5:2 ratio. Addition of the same ligand (2 equiv) to Y(CH(2)SiMe(3))(3)(thf)(2), however, generated 1 b together with the novel complex 1 c, the first well defined yttrium mono(alkyl) complex (η(5):κ-C(5)Me(4)-C(5)H(4)N)[C(5)HMe(3)(η(3)-CH(2))-C(5)H(4)N-κ]Y(CH(2)SiMe(3)) containing a rare κ/η(3)-allylic coordination mode in which the C-H bond activation occurs unexpectedly with the allylic methyl group rather than conventionally on Cp ring. If the central metal was changed to lutetium, the equimolar reaction between Lu(CH(2)SiMe(3))(3)(thf)(2) and C(5)Me(4)H-C(5)H(4)N exclusively afforded the bis(alkyl) product (η(5):κ-C(5)Me(4)-C(5)H(4)N)Lu(CH(2)SiMe(3))(2)(thf) (2 a). Similarly, the reaction between the ligand (2 equiv) and Lu(CH(2)SiMe(3))(3)(thf)(2) gave the mono(alkyl) complex (η(5):κ-C(5)Me(4)-C(5)H(4)N)(2)LuCH(2)SiMe(3) (2 b), in which no ligand redistribution was observed. Strikingly, treatment of Sc(CH(2)SiMe(3))(3)(thf)(2) with C(5)Me(4)H-C(5)H(4)N in either 1:1 or 1:2 ratio at 0 °C generated the first cyclopentadienide-based scandium zwitterionic "tuck-over" complex 3, (η(5):κ-C(5)Me(4)-C(5)H(4)N)Sc(thf)[μ-η(5):η(1):κ-C(5)Me(3)(CH(2))-C(5)H(4)N]Sc(CH(2)SiMe(3))(3). In the zwitterion, the dianionic ligand [C(5)Me(3)(CH(2))-C(5)H(4)N](2-) binds both to Sc1(3+) and to Sc2(3+), in η(5) and η(1)/κ modes. In addition, the reaction chemistry, the molecular structures, and the mechanism are also discussed in detail.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

An Unusual Organoyttrium Alkyl Complex Containing a [C₅HMe₃(η³‐CH₂)‐C₅H₄N‐κ]⁻ Ligand and an Elusive Cyclopentadienide‐Based Scandium Tuck‐Over Zwitterion Obtained by CH Bond Activation

Jian¹,

Cui²

2011

“…In a similar manner, Köelle et al. have prepared the related nonamethylruthenocenylmethylium cation [Cp*RuC 5 Me 4 CH 2 ] + ( 3 , Scheme ) by reaction of decamethylruthenocene with [CPh 3 ] + . It should be noted however that the analogous reaction of 1,1′‐dimethylruthenocene failed to give the (1′‐methylruthenocenyl)methylium cation, suggesting its lower stability.…”

Section: Resultsmentioning

confidence: 99%

The First Triple‐Decker Complex with a Carbenium Center, [CpCo(μ‐C₃B₂Me₅)RuC₅Me₄CH₂]⁺: Synthesis, Reactivity, X‐Ray Structure, and Bonding

Muratov

Romanov

Corsini

et al. 2017

The first derivative of the methylium cation with the triple-decker substituent, [CpCo(C B Me )RuC Me CH ]PF (2PF ), was synthesized from the reaction of the triple-decker complex CpCo(C B Me )RuCp* (1) with the salt of the trityl cation [CPh ] . The X-ray crystal structure of 2PF reveals that the methylium carbon is bound to the ruthenium with Ru-C bond length of 2.259 Å and corresponds to the description of its structure as η -fulvene-ruthenium. Reactions of 2PF with nucleophiles OH , Ph P, Et N led to the corresponding derivatives of 1 in high yields. Aromatic amines PhNEt and 4-MeC H NH react with 2PF to give the electrophilic aromatic substitution products quantitatively. Chemical reduction of 2PF with Zn powder in tetrahydrofuran leads to the formation of the bis(triple-decker) derivative (CpCo(C B Me )RuC Me CH ) (10) with a CH CH -bridge. The structures of complexes 4, 7-10 were determined by X-ray diffraction. Density functional calculations support the crystallographically determined geometry of 2 and allow rationalization of some characteristics of its structure, spectroscopy, and reactivity.

“…Al arge body of work hase manated from the A. N. Nesmeyanov Instituteo fO rganoelement Compounds (Moscow,R ussian Federation)o ver the past 30 years on the organometallic chemistry of metallocenes, especially decamethylmetallocenes, [50][51][52][53][54][55][56][57] including the UV photolysis of [Cp* 2 Ru II ]i ns trong acidic solutions. [58,59] The main focus of thesep reviouss tudies was the synthesis and characterization of cationic derivatives of [Cp* 2 Ru II ], especially with regard to the stabilization of up to three carbocationic sites (CH 2 + )o nt he cyclopentadienyl rings by as ingle ruthenium metal atom [54,55] and the reactivity of these cations towards strong nucleophiles.…”

Section: Photogeneration Of H 2 Fromacidified Dce By Using [Cp 2 *Ru mentioning

confidence: 99%

Mechanistic Study on the Photogeneration of Hydrogen by Decamethylruthenocene

Rivier

Peljo

Maye

et al. 2019

Detailed studies on hydrogen evolution by decamethylruthenocene ([Cp* 2 Ru II ]) highlighted that metallocenes are capable of photoreducing hydrogen without the need for an additionals ensitizer.E lectrochemical, gas chromatographic, and spectroscopic (UV/Vis, 1 Ha nd 13 CNMR) measurements corroborated by DFTc alculations indicated that the production of hydrogen occurs by at wo-stepp rocess. First, decamethylruthenocene hydride [Cp* 2 Ru IV (H)] + is formed in the presence of an organic acid. Subsequently, [Cp* 2 Ru IV (H)] + is reversibly reduced in ah eterolytic reaction with one-photon excitation leadingt oafirst releaseo fh y-drogen. Thereafter,t he resultant decamethylruthenocenium ion [Cp* 2 Ru III ] + is further reduced with as econd releaseo f hydrogenb yd eprotonation of am ethyl group of [Cp* 2 Ru III ] + .E xperimental and computational data show spontaneous conversion of [Cp* 2 Ru II ]t o[ Cp* 2 Ru IV (H)] + in the presence of protons. Calculations highlight that the first reductioni se ndergonic (DG 0 = 108 kJ mol À1 )a nd needs an input of energy by light for the reactiont oo ccur.T he hydricityo ft he methylp rotons of [Cp* 2 Ru II ]w as also considered.Supporting information and the ORCID identification number(s) for the author(s) of this articlecan be found under: https://doi.