18 research outputs found
Lithium Aluminates on a Molecular Titanium Oxide
No full textLithium aluminates Li[Al(O-2,6-Me<sub>2</sub>C<sub>6</sub>H<sub>3</sub>)R′<sub>3</sub>] (R′ = Et, Ph) react with
the
μ<sub>3</sub>-alkylidyne oxoderivative ligands [{Ti(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)(μ-O)}<sub>3</sub>(μ<sub>3</sub>-CR)] [R = H (<b>1</b>), Me (<b>2</b>)] to afford
the aluminum–lithium–titanium cubane complexes [{R′<sub>3</sub>Al(μ-O-2,6-Me<sub>2</sub>C<sub>6</sub>H<sub>3</sub>)Li}(μ<sub><i>3</i></sub>-O)<sub>3</sub>{Ti(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)}<sub>3</sub>(μ<sub>3</sub>-CR)] [R =
H, R′ = Et (<b>5</b>), Ph (<b>7</b>); R = Me, R′
= Et (<b>6</b>), Ph (<b>8</b>)]. Complex <b>7</b> evolves with the formation of a lithium dicubane species and a Li{Al(μ-O-2,6-Me<sub>2</sub>C<sub>6</sub>H<sub>3</sub>)Ph<sub>3</sub>}<sub>2</sub>] unit
C–H Activation on an Oxo-Bridged Dititanium Complex: From Alkyl to μ‑Alkylidene Functionalities
No full textThermal treatment
of the dinuclear compound [{Ti(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)(CH<sub>2</sub>SiMe<sub>3</sub>)<sub>2</sub>}<sub>2</sub>(μ-O)] (<b>1</b>) provides
the formation of the metallacycle derivatives [Ti<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>2</sub>(μ-CH<sub>2</sub>SiMe<sub>2</sub>CH<sub>2</sub>)(CH<sub>2</sub>SiMe<sub>3</sub>)<sub>2</sub>(μ-O)] (<b>2</b>) and [Ti<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>2</sub>(μ-CH<sub>2</sub>SiMe<sub>2</sub>CH<sub>2</sub>)<sub>2</sub>(μ-O)] (<b>3</b>) and the μ-alkylidene
complex [Ti<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>2</sub>(μ-CH<sub>2</sub>SiMe<sub>2</sub>CH<sub>2</sub>)(μ-CHSiMe<sub>3</sub>)(μ-O)] (<b>4</b>) by sequential carbon–hydrogen activation processes.
The reaction of <b>3</b> with <i>tert</i>-butylisocyanide,
in 1:1 and 1:2 ratios, leads to the η<sup>2</sup>-iminoacyl
complexes [Ti<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>2</sub>(μ-<i>t</i>BuNCCH<sub>2</sub>SiMe<sub>2</sub>CH<sub>2</sub>)(μ-CH<sub>2</sub>SiMe<sub>2</sub>CH<sub>2</sub>)(μ-O)] (<b>5</b>) and [Ti<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>2</sub>(μ-<i>t</i>BuNCCH<sub>2</sub>SiMe<sub>2</sub>CH<sub>2</sub>)<sub>2</sub>(μ-O)]
(<b>6</b>), respectively. The molecular structures of complexes <b>3</b>, <b>4</b>, <b>5</b>, and <b>6</b> have
been determined by single-crystal X-ray diffraction analyses
C–H Activation on an Oxo-Bridged Dititanium Complex: From Alkyl to μ‑Alkylidene Functionalities
No full textThermal treatment
of the dinuclear compound [{Ti(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)(CH<sub>2</sub>SiMe<sub>3</sub>)<sub>2</sub>}<sub>2</sub>(μ-O)] (<b>1</b>) provides
the formation of the metallacycle derivatives [Ti<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>2</sub>(μ-CH<sub>2</sub>SiMe<sub>2</sub>CH<sub>2</sub>)(CH<sub>2</sub>SiMe<sub>3</sub>)<sub>2</sub>(μ-O)] (<b>2</b>) and [Ti<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>2</sub>(μ-CH<sub>2</sub>SiMe<sub>2</sub>CH<sub>2</sub>)<sub>2</sub>(μ-O)] (<b>3</b>) and the μ-alkylidene
complex [Ti<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>2</sub>(μ-CH<sub>2</sub>SiMe<sub>2</sub>CH<sub>2</sub>)(μ-CHSiMe<sub>3</sub>)(μ-O)] (<b>4</b>) by sequential carbon–hydrogen activation processes.
The reaction of <b>3</b> with <i>tert</i>-butylisocyanide,
in 1:1 and 1:2 ratios, leads to the η<sup>2</sup>-iminoacyl
complexes [Ti<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>2</sub>(μ-<i>t</i>BuNCCH<sub>2</sub>SiMe<sub>2</sub>CH<sub>2</sub>)(μ-CH<sub>2</sub>SiMe<sub>2</sub>CH<sub>2</sub>)(μ-O)] (<b>5</b>) and [Ti<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>2</sub>(μ-<i>t</i>BuNCCH<sub>2</sub>SiMe<sub>2</sub>CH<sub>2</sub>)<sub>2</sub>(μ-O)]
(<b>6</b>), respectively. The molecular structures of complexes <b>3</b>, <b>4</b>, <b>5</b>, and <b>6</b> have
been determined by single-crystal X-ray diffraction analyses
An Effective Route to Dinuclear Niobium and Tantalum Imido Complexes
No full textThermal treatment
of the trichloro complexes [MCl<sub>3</sub>(NR)py<sub>2</sub>] (R
= <i>t</i>Bu, Xyl; M = Nb, Ta) (Xyl = 2,6-Me<sub>2</sub>C<sub>6</sub>H<sub>3</sub>) under vacuum affords the dinuclear imido
species [MCl<sub>2</sub>(μ-Cl)(NR)py]<sub>2</sub> (R = <i>t</i>Bu, Xyl; M = Nb <b>1</b>, <b>3</b>; Ta <b>2</b>, <b>4</b>) with loss of pyridine. Complexes <b>1</b>–<b>4</b> can be easily transformed to the mononuclear
starting materials [MCl<sub>3</sub>(NR)py<sub>2</sub>] (R = <i>t</i>Bu, Xyl; M = Nb, Ta) upon reaction with pyridine. While
reactions of compounds <b>1</b> and <b>2</b> with a series
of alkylating reagents render the mononuclear peralkylated imido complexes
[MR<sub>3</sub>(N<i>t</i>Bu)] (R = Me, CH<sub>2</sub>Ph,
CH<sub>2</sub>CMe<sub>3</sub>, CH<sub>2</sub>CMePh, CH<sub>2</sub>SiMe<sub>3</sub>), the analogous treatment with allylmagnesium chloride
results in the formation of the dinuclear niobium(IV) derivative [(N<i>t</i>Bu)(η<sup>3</sup>-C<sub>3</sub>H<sub>5</sub>)M(μ-C<sub>3</sub>H<sub>5</sub>)(μ-Cl)<sub>2</sub>M(N<i>t</i>Bu)py<sub>2</sub>] (<b>5</b>). Additionally, the treatment
of the starting materials <b>1</b> and <b>2</b> with the
organosilicon reductant 1,4-bis(trimethylsilyl)-1,4-diaza-2,5-cyclohexadiene
yields the pyridyl-bridged dinuclear derivatives [M<sub>2</sub>Cl<sub>2</sub>(μ-Cl)<sub>2</sub>(N<i>t</i>Bu)<sub>2</sub>py<sub>2</sub>]<sub>2</sub>(μ-NC<sub>4</sub>H<sub>4</sub>N)<sub>2</sub> (M = Nb <b>6</b>, Ta <b>7</b>). Controlled hydrolysis
reaction of <b>1</b> and <b>2</b> affords the oxo chlorido-bridged
products [MCl(μ-Cl)(N<i>t</i>Bu)py]<sub>2</sub>(μ-O)
(M = Nb <b>8</b>, Ta <b>9</b>) in a quantitative way,
while the treatment of these latter with one more equivalent of pyridine
led to complexes [MCl<sub>2</sub>(N<i>t</i>Bu)py<sub>2</sub>]<sub>2</sub>(μ-O) (M = Nb <b>10</b>, Ta <b>11</b>). Structural study of these dinuclear imido derivatives has been
also performed by X-ray crystallography
Reactivity with Electrophiles of Imido Groups Supported on Trinuclear Titanium Systems
No full textSeveral
trinuclear titanium complexes bearing amido μ-NHR, imido μ-NR,
and nitrido μ<sub><i>n</i></sub>-N ligands have been
prepared by reaction of [{Ti(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)(μ-NH)}<sub>3</sub>(μ<sub>3</sub>-N)] (<b>1</b>) with 1 equiv of electrophilic reagents ROTf (R = H, Me,
SiMe<sub>3</sub>; OTf = OSO<sub>2</sub>CF<sub>3</sub>). Treatment
of <b>1</b> with triflic acid or methyl triflate in toluene
at room temperature affords the precipitation of compounds [Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-NH)<sub>2</sub>(μ-NH<sub>2</sub>)(OTf)] (<b>2</b>) or [Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-NH)(μ-NH<sub>2</sub>)(μ-NMe)(OTf)] (<b>3</b>). Complexes <b>2</b> and <b>3</b> exhibit a fluxional behavior in solution consisting
of proton exchange between μ-NH<sub>2</sub> and μ-NH groups,
assisted by the triflato ligand, as could be inferred from a dynamic
NMR spectroscopy study. Monitoring by NMR spectroscopy the reaction
course of <b>1</b> with MeOTf allows the characterization of
the methylamido intermediate [Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-NH)<sub>2</sub>(μ-NHMe)(OTf)] (<b>4</b>), which readily rearranges
to give <b>3</b> by a proton migration from the NHMe amido group
to the NH imido ligands. The treatment of <b>1</b> with 1 equiv
of Me<sub>3</sub>SiOTf produces the stable ionic complex [Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-NH)<sub>2</sub>(μ-NHSiMe<sub>3</sub>)][OTf] (<b>5</b>) with a disposition of the nitrogen ligands
similar to that of <b>4</b>. Complex <b>5</b> reacts with
1 equiv of [K{N(SiMe<sub>3</sub>)<sub>2</sub>}] at room temperature
to give [Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-N)(μ-NH)(μ-NHSiMe<sub>3</sub>)] (<b>6</b>), which at 85 °C rearranges to the
trimethylsilylimido derivative [Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-NH)<sub>2</sub>(μ-NSiMe<sub>3</sub>)] (<b>7</b>). Treatment of <b>7</b> with [K{N(SiMe<sub>3</sub>)<sub>2</sub>}] affords the potassium
derivative [K{(μ<sub>3</sub>-N)(μ<sub>3</sub>-NH)(μ<sub>3</sub>-NSiMe<sub>3</sub>)Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)}] (<b>8</b>), which upon addition of 18-crown-6 leads to the ion pair
[K(18-crown-6)][Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-N)(μ-NH)(μ-NSiMe<sub>3</sub>)] (<b>9</b>). The X-ray crystal structures of <b>2</b>, <b>5</b>, <b>6</b>, and <b>8</b> have
been determined
Reactivity with Electrophiles of Imido Groups Supported on Trinuclear Titanium Systems
No full textSeveral
trinuclear titanium complexes bearing amido μ-NHR, imido μ-NR,
and nitrido μ<sub><i>n</i></sub>-N ligands have been
prepared by reaction of [{Ti(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)(μ-NH)}<sub>3</sub>(μ<sub>3</sub>-N)] (<b>1</b>) with 1 equiv of electrophilic reagents ROTf (R = H, Me,
SiMe<sub>3</sub>; OTf = OSO<sub>2</sub>CF<sub>3</sub>). Treatment
of <b>1</b> with triflic acid or methyl triflate in toluene
at room temperature affords the precipitation of compounds [Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-NH)<sub>2</sub>(μ-NH<sub>2</sub>)(OTf)] (<b>2</b>) or [Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-NH)(μ-NH<sub>2</sub>)(μ-NMe)(OTf)] (<b>3</b>). Complexes <b>2</b> and <b>3</b> exhibit a fluxional behavior in solution consisting
of proton exchange between μ-NH<sub>2</sub> and μ-NH groups,
assisted by the triflato ligand, as could be inferred from a dynamic
NMR spectroscopy study. Monitoring by NMR spectroscopy the reaction
course of <b>1</b> with MeOTf allows the characterization of
the methylamido intermediate [Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-NH)<sub>2</sub>(μ-NHMe)(OTf)] (<b>4</b>), which readily rearranges
to give <b>3</b> by a proton migration from the NHMe amido group
to the NH imido ligands. The treatment of <b>1</b> with 1 equiv
of Me<sub>3</sub>SiOTf produces the stable ionic complex [Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-NH)<sub>2</sub>(μ-NHSiMe<sub>3</sub>)][OTf] (<b>5</b>) with a disposition of the nitrogen ligands
similar to that of <b>4</b>. Complex <b>5</b> reacts with
1 equiv of [K{N(SiMe<sub>3</sub>)<sub>2</sub>}] at room temperature
to give [Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-N)(μ-NH)(μ-NHSiMe<sub>3</sub>)] (<b>6</b>), which at 85 °C rearranges to the
trimethylsilylimido derivative [Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-NH)<sub>2</sub>(μ-NSiMe<sub>3</sub>)] (<b>7</b>). Treatment of <b>7</b> with [K{N(SiMe<sub>3</sub>)<sub>2</sub>}] affords the potassium
derivative [K{(μ<sub>3</sub>-N)(μ<sub>3</sub>-NH)(μ<sub>3</sub>-NSiMe<sub>3</sub>)Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)}] (<b>8</b>), which upon addition of 18-crown-6 leads to the ion pair
[K(18-crown-6)][Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-N)(μ-NH)(μ-NSiMe<sub>3</sub>)] (<b>9</b>). The X-ray crystal structures of <b>2</b>, <b>5</b>, <b>6</b>, and <b>8</b> have
been determined
Reactivity with Electrophiles of Imido Groups Supported on Trinuclear Titanium Systems
No full textSeveral
trinuclear titanium complexes bearing amido μ-NHR, imido μ-NR,
and nitrido μ<sub><i>n</i></sub>-N ligands have been
prepared by reaction of [{Ti(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)(μ-NH)}<sub>3</sub>(μ<sub>3</sub>-N)] (<b>1</b>) with 1 equiv of electrophilic reagents ROTf (R = H, Me,
SiMe<sub>3</sub>; OTf = OSO<sub>2</sub>CF<sub>3</sub>). Treatment
of <b>1</b> with triflic acid or methyl triflate in toluene
at room temperature affords the precipitation of compounds [Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-NH)<sub>2</sub>(μ-NH<sub>2</sub>)(OTf)] (<b>2</b>) or [Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-NH)(μ-NH<sub>2</sub>)(μ-NMe)(OTf)] (<b>3</b>). Complexes <b>2</b> and <b>3</b> exhibit a fluxional behavior in solution consisting
of proton exchange between μ-NH<sub>2</sub> and μ-NH groups,
assisted by the triflato ligand, as could be inferred from a dynamic
NMR spectroscopy study. Monitoring by NMR spectroscopy the reaction
course of <b>1</b> with MeOTf allows the characterization of
the methylamido intermediate [Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-NH)<sub>2</sub>(μ-NHMe)(OTf)] (<b>4</b>), which readily rearranges
to give <b>3</b> by a proton migration from the NHMe amido group
to the NH imido ligands. The treatment of <b>1</b> with 1 equiv
of Me<sub>3</sub>SiOTf produces the stable ionic complex [Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-NH)<sub>2</sub>(μ-NHSiMe<sub>3</sub>)][OTf] (<b>5</b>) with a disposition of the nitrogen ligands
similar to that of <b>4</b>. Complex <b>5</b> reacts with
1 equiv of [K{N(SiMe<sub>3</sub>)<sub>2</sub>}] at room temperature
to give [Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-N)(μ-NH)(μ-NHSiMe<sub>3</sub>)] (<b>6</b>), which at 85 °C rearranges to the
trimethylsilylimido derivative [Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-NH)<sub>2</sub>(μ-NSiMe<sub>3</sub>)] (<b>7</b>). Treatment of <b>7</b> with [K{N(SiMe<sub>3</sub>)<sub>2</sub>}] affords the potassium
derivative [K{(μ<sub>3</sub>-N)(μ<sub>3</sub>-NH)(μ<sub>3</sub>-NSiMe<sub>3</sub>)Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)}] (<b>8</b>), which upon addition of 18-crown-6 leads to the ion pair
[K(18-crown-6)][Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)(μ-N)(μ-NH)(μ-NSiMe<sub>3</sub>)] (<b>9</b>). The X-ray crystal structures of <b>2</b>, <b>5</b>, <b>6</b>, and <b>8</b> have
been determined
Systematic Approach for the Construction of Niobium and Tantalum Sulfide Clusters
No full textTreatment of the
imido complexes [MCl<sub>3</sub>(NR)py<sub>2</sub>] (R = <sup><i>t</i></sup>Bu, 2,6-Me<sub>2</sub>C<sub>6</sub>H<sub>3</sub>;
M = Nb <b>1</b>, <b>3</b>; Ta <b>2</b>, <b>4</b>) (Xyl = 2,6-Me<sub>2</sub>C<sub>6</sub>H<sub>3</sub>) with (Me<sub>3</sub>Si)<sub>2</sub>S in a 1:1 ratio afforded the new cube-type
sulfide clusters [MCl(NR)py(μ<sub>3</sub>-S)]<sub>4</sub> (R
= <sup><i>t</i></sup>Bu, 2,6-Me<sub>2</sub>C<sub>6</sub>H<sub>3</sub>; M = Nb <b>5</b>, <b>7</b>; Ta <b>6</b>, <b>8</b>) with loss of Me<sub>3</sub>SiCl. Reactions of <b>5</b> and <b>6</b> with cyclopentadienyllithium in 1:4 ratio
resulted in the rupture of the coordinative M–S bonds and the
replacement of a pyridine molecule and a chlorine atom by an η<sup>5</sup>-cyclopentadienyl group in each metal center, affording the
compounds [M(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)(N<sup><i>t</i></sup>Bu)(μ-S)]<sub>4</sub> (M = Nb <b>9</b>, Ta <b>10</b>). These processes may develop through
formation of the complexes [M<sub>4</sub>(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)<sub>2</sub>(μ-Cl)(N<sup><i>t</i></sup>Bu)<sub>4</sub>py<sub>2</sub>(μ<sub>3</sub>-S)<sub>2</sub>(μ-S)<sub>2</sub>](C<sub>5</sub>H<sub>5</sub>) (M = Nb <b>11</b>, Ta <b>12</b>), also obtained
by reaction of <b>5</b> and <b>6</b> with cyclopentadienyllithium
in 1:3 ratio. As further evidence, <b>11</b> and <b>12</b> led to complexes <b>9</b> and <b>10</b> by treatment
with one more equivalent of the lithium reagent. The structural study
of these metal sulfide clusters has been also performed by X-ray crystallography
Redox-Active Behavior of the [{Ti(η<sup>5</sup>‑C<sub>5</sub>Me<sub>5</sub>)(μ-NH)}<sub>3</sub>(μ<sub>3</sub>‑N)] Metalloligand
No full textTreatment of [Cl<sub>3</sub>Y{(μ<sub>3</sub>-NH)<sub>3</sub>Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)}] with [K(C<sub>5</sub>Me<sub>5</sub>)] in toluene gives C<sub>10</sub>Me<sub>10</sub> and the paramagnetic [K(μ-Cl)<sub>3</sub>Y{(μ<sub>3</sub>-NH)<sub>3</sub>Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)}] (<b>3</b>) derivative. Crystallization of <b>3</b> in pyridine affords the potassium-free [Cl<sub>2</sub>(py)<sub>2</sub>Y{(μ<sub>3</sub>-NH)<sub>3</sub>Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)}] (<b>4</b>) complex. Whereas the reaction of <b>3</b> with 1 equiv of 18-crown-6 leads to the molecular complex [(18-crown-6)K(μ-Cl)<sub>3</sub>Y{(μ<sub>3</sub>-NH)<sub>3</sub>Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)}] (<b>5</b>), the analogous treatment of <b>3</b> with cryptand-222 affords the ion pair [K(crypt-222)][Cl<sub>3</sub>Y{(μ<sub>3</sub>-NH)<sub>3</sub>Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)}] (<b>6</b>). The X-ray crystal structures of <b>4</b>, <b>5</b>, and <b>6</b> have been determined. Density
functional theory (DFT) calculations have elucidated the electronic
structure of these species, which should be regarded as containing
trivalent Y bonded to the {(μ<sub>3</sub>-NH)<sub>3</sub>Ti<sub>3</sub>(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>3</sub>(μ<sub>3</sub>-N)} metalloligand radical anion
Partial Hydrogenation of a Tetranuclear Titanium Nitrido Complex with Ammonia Borane
No full textThe treatment of [{Ti(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)}<sub>4</sub>(μ<sub>3</sub>-N)<sub>4</sub>] with NH<sub>3</sub>BH<sub>3</sub> leads to the paramagnetic
imidonitrido complex [{Ti(η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)}<sub>4</sub>(μ<sub>3</sub>-N)<sub>3</sub>(μ<sub>3</sub>-NH)], which can also be obtained by stepwise proton and electron
transfer with HOTf and [K(C<sub>5</sub>Me<sub>5</sub>)]
