Co-complexation of Lithium Gallates on the Titanium Molecular Oxide {[Ti(η⁵-C₅Me₅)(μ-O)}₃(μ₃-CH)]

Abstract

Amide and lithium aryloxide gallates [Li(+){RGaPh(3)}(-)] (R = NMe(2), O-2,6-Me(2)C(6)H(3)) react with the μ(3)-alkylidyne oxoderivative ligand [{Ti(η(5)-C(5)Me(5))(μ-O)}(3)(μ(3)-CH)] (1) to afford the gallium-lithium-titanium cubane complexes [{Ph(3)Ga(μ-R)Li}{Ti(η(5)-C(5)Me(5))(μ-O)}(3)(μ(3)-CH)] [R = NMe(2) (3), O-2,6-Me(2)C(6)H(3) (4)]. The same complexes can be obtained by treatment of the [Ph(3)Ga(μ(3)-O)(3){Ti(η(5)-C(5)Me(5))}(3)(μ(3)-CH)] (2) adduct with the corresponding lithium amide or aryloxide, respectively. Complex 3 evolves with formation of 5 as a solvent-separated ion pair constituted by the lithium dicubane cationic species [Li{(μ(3)-O)(3)Ti(3)(η(5)-C(5)Me(5))(3)(μ(3)-CH)}(2)](+) together with the anionic [(GaPh(3))(2)(μ-NMe(2))](-) unit. On the other hand, the reaction of 1 with Li(p-MeC(6)H(4)) and GaPh(3) leads to the complex [Li{(μ(3)-O)(3)Ti(3)(η(5)-C(5)Me(5))(3)(μ(3)-CH)}(2)][GaLi(p-MeC(6)H(4))(2)Ph(3)] (6). X-ray diffraction studies were performed on 1, 2, 4, and 5, while trials to obtain crystals of 6 led to characterization of [Li{(μ(3)-O)(3)Ti(3)(η(5)-C(5)Me(5))(3)(μ(3)-CH)}(2)][PhLi(μ-C(6)H(5))(2)Ga(p-MeC(6)H(4))Ph] 6a.

Contact and solvent-separated ion pair aluminium “ate” complexes on a titanium oxide molecular model

“…9( 13 (tmp = 2,2,6,6-tetramethylpiperidide) and [AlMe 3 N(SiMe 3 ) 2 11,13,14 As shown in Fig. 9( 13 (tmp = 2,2,6,6-tetramethylpiperidide) and [AlMe 3 N(SiMe 3 ) 2 11,13,14 As shown in Fig.…”

“…Also, the 13 C{ 1 H}NMR signals corresponding to the NMe 2 fragment appear slightly high field shifted, 42.1 (9) and 41.4 (10) ppm, when compared to the monocubane contact ion pair complexes 7 and 8. 9 With the results of the co-complexation processes with lithium dimethylamide in hand, we wondered whether that chemical behaviour was reproducible, using reagents like Complexes 11 and 12 were obtained by elimination of a Li-[Al(CH 2 SiMe 3 )Ph 3 ] aluminate unit from intermediates 11h and 12h respectively, which could only be isolated when the reactions were carried out in hexane. 9 With the results of the co-complexation processes with lithium dimethylamide in hand, we wondered whether that chemical behaviour was reproducible, using reagents like Complexes 11 and 12 were obtained by elimination of a Li-[Al(CH 2 SiMe 3 )Ph 3 ] aluminate unit from intermediates 11h and 12h respectively, which could only be isolated when the reactions were carried out in hexane.…”

“…7 Recently, we have communicated the capability of the molecular organometallic oxides [{Ti(η 5 -C 5 Me 5 )(μ-O)} 3 (μ 3 -CR)] [R = H (1), Me (2)] to support heteroleptic aromatic lithium aluminium "ate" fragments 8 and have been able to identify unambiguously the formation of characteristic contact and solventseparated ion pair structures containing titanium-lithiumaluminium (Scheme 1). 9 In this context, and in order to complete this study, herein we describe the co-complexation reactions between lithium amide/alkyl aluminates and the aforementioned μ 3 -alkylidyne oxoderivative ligands. Moreover, the evolution of one of these complexes led to the formation of a solvent-separated ion pair structure containing a lithium dicubane species and a [Li{Al(μ-O-2,6-Me 2 C 6 H 3 )Ph 3 } 2 ] unit.…”

Beyond Takai's Olefination Reagent: Persistent Dehalogenation Emerges in a Chromium(III)‐μ3‐Methylidyne Complex

“…[7] Purple trivalent A has remained the only structurally characterized methylidyne complex of chromium, [7,8] On the other hand the M3(μ3-CH) entity exhibits a common structural motif detected throughout d-transition metal chemistry (Ti, Co, Fe, Ru, Re and Os). [9] Prominent examples of the μ3alkylidyne compound class are tricobalt nonacarbonyl clusters, first mentioned 1970 by Seyferth et al [10] Methylidyne complexes structurally related/ isostructural to A comprise [{Cp*Ti(μ-O)}3(μ3-CH)] [11] and [Cp*3Mo3(µ-O)2(µ-CH2)(µ3-CH)] [12] the reactivity of which has been investigated as well. Complex A has been obtained by thermal treatment (60 °C) of [CpCr(CH3)(μ2-Cl)]2 via multiple abstraction of hydrogen from a methyl ligand, [13] while its reactivity was not commented on.…”

“…[7,8] On the other hand, the M 3 (m 3 -CH) entity exhibits ac ommon structural motif detected throughout d-transition metal chemistry (Ti, Fe,C o, Ru, Re and Os). [9] Prominent examples of the m 3 -alkylidyne compound class are tricobalt nonacarbonyl clusters,w hich were investigated comprehensively by Seyferth et al [10] Methylidyne complexes structurally related to A comprise [{Cp*Ti(m 2 -O)} 3 (m 3 -CH)] [11] and [Cp* 3 Mo 3 (m 2 -O) 2 (m 2 -CH 2 )(m 3 -CH)] [12] the reactivity of which has been investigated as well.…”