The coordination modes of simple diarylmagnesium species: Some representative X-ray crystal structures

Markies, Peter R.; Schat, G.; Akkerman, Otto S.; Bickelhaupt, F.; Smeets, W. J. J.; Sluis, P. van der; Spek, Anthony L.

doi:10.1016/0022-328x(90)85161-q

Cited by 48 publications

(29 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Mg À C Ph bond length of 214.1(3) pm is in agreement with other magnesium-phenyl distances known from the literature. [47] The distortion of the phenyl ligand (e.g., an acute C-C-C angle of 113.38 at the ispo-carbon atom) is comparable to examples known from the literature in which an aryl ligand is bonded to an electropositive metal. The additionally coordinated thf molecule (dA C H T U N G T R E N N U N G (MgÀ O) = 220.5(2) pm) is located between the remaining two pyrazolyl groups at N2 and N6.…”

Section: N-mentioning

confidence: 89%

Syntheses, Reactivity and DFT Studies of Group 2 and Group 12 Metal Complexes of Tris(pyrazolyl)methanides Featuring “Free” Pyramidal Carbanions

Bigmore

Meyer

Krummenacher

et al. 2008

Chemistry A European J

View full text Add to dashboard Cite

Reactions of HC(Me2pz)3 with Grignard reagents, dialkyl magnesium compounds and dimethylzinc are reported, together with a DFT study on some of the aspects of this chemistry. Reactions of HC(Me2pz)3 with MeMgX (X=Cl or Br) gave the half-sandwich zwitterionic compounds [Mg((Me)Tpmd)X] (X=Cl (2) or Br (3); (Me)Tpmd(-)=[C(Me2pz)3](-)). Addition of HCl to 2 gave the structurally characterised half-sandwich compound [Mg{HC(Me2pz)3}Cl2(thf)] (4). The zwitterionic sandwich compound [Mg(MeTpmd)2] (5) formed in low yields in the reaction of MeMgX with HC(Me2pz)3 but was readily prepared from HC(Me2pz)3 and either MgnBu2 or MgPh2. The structurally characterised compound 5 contains two "naked" sp3-hybridised carbanions fully separated from the dicationic metal centre. Only by using MgPh2 as starting material could the half-sandwich compound [Mg(MeTpmd)Ph(thf)] (6) be isolated. The zwitterionic sandwich compound 5 reacted with HOTf (OTf(-)=[O3SCF3](-)) to form the dication [Mg{HC(Me2pz)3}2]2+ (7(2+)), which was structurally characterised. Pulsed field gradient spin-echo (PGSE) diffusion NMR spectroscopy revealed both compounds to be intact in solution. In contrast to the magnesium counterparts, HC(Me2pz)3 reacted only slowly with ZnMe2 (and not at all with ZnPh2) to form the half-sandwich zwitterion [Zn(MeTpmd)Me] (8), which contains a cationic methylzinc moiety separated from a single sp3-hybridised carbanion. Density functional calculations on the zwitterions [M(MeTpmd)Me] and [M(MeTpmd)2] (M=Mg, Zn) revealed that the HOMO in each case is a (Me)Tpmd-based carbanion lone pair. The kappa 1C isomers of [M(MeTpmd)Me] were calculated to be considerably less stable than their kappa 3N-bound counterparts, with the largest gain in energy for Mg due to the greater ease of electron transfer from metal to the (Me)Tpmd apical carbon atom on formation of the zwitterion. Moreover, the computed M-C bond dissociation enthalpies of the kappa 1C isomers of [M(MeTpmd)Me] are considerably higher than expected by simple extrapolation from the corresponding computed H-C bond dissociation enthalpy.

show abstract

Section: N-mentioning

confidence: 89%

Syntheses, Reactivity and DFT Studies of Group 2 and Group 12 Metal Complexes of Tris(pyrazolyl)methanides Featuring “Free” Pyramidal Carbanions

Bigmore

Meyer

Krummenacher

et al. 2008

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…1,4-Dioxane (22 mL, 0.25 mol) was then added dropwise to this solution. The reaction mixture was kept overnight at room temperature and precipitated [MgBr 2 (dx) 2 Synthesis of [Ph 2 Mg(h 1 -dx) 3 ] (3-Ph): A commercially available 1.0 m PhMgBr solution in THF (50 mL, 50 mmol) and dioxane (50 mL) were combined and the mixture heated at reflux. After standing overnight the precipitate was removed by means of a Schlenk frit covered with diatomaceous earth.…”

Section: Synthesis Of [(N-c 4 H 9 ) 2 Mg(dx)] (1-nbu)mentioning

confidence: 99%

“…[1,2] Besides the direct synthesis (yielding Grignard reagents), hydromagnesiation of alkenes with activated magnesium hydride [3] and the THF method by the precipitation of sparingly soluble Mg(thf) 6 I 2 from RMgI solutions [4] have allowed, in special cases, the isolation of MgR 2 . [1,2] Besides the direct synthesis (yielding Grignard reagents), hydromagnesiation of alkenes with activated magnesium hydride [3] and the THF method by the precipitation of sparingly soluble Mg(thf) 6 I 2 from RMgI solutions [4] have allowed, in special cases, the isolation of MgR 2 .…”

Section: Introductionmentioning

confidence: 99%

Structure–Solubility Relationship of 1,4‐Dioxane Complexes of Di(hydrocarbyl)magnesium

Fischer

Görls

Meisinger

et al. 2019

Chemistry A European J

View full text Add to dashboard Cite

Systematic variation of the 1,4-dioxane (dx) concentration during the precipitation of sparingly soluble [MgBr 2 (dx) 2 ] from ethereal Grignard solutions of RMgBr has allowed the structural investigation of crystallized [R 2 Mg(dx) n ] (n = 1, 1.5, 2, and 3), which form during this dioxane method, depending on the bulkiness of R. The numbering of the complexes explored in this study is based on the number n of dioxane molecules per magnesium atom, followed by the substituent R; an apostrophe denotes coordination polymers. The following derivatives were studied by X-ray crystal-structure determination and NMR spectroscopy :(1.5-oTol), and [(Me 3 Si-CC) 2 Mg(dx) 1.5 ] 1 (1.5'-C 2 SiMe 3 ); n = 2: [tBu 2 Mg(dx) 2 ] (2-tBu) and [oTol 2 Mg(dx) 2 ] (2-oTol); n = 3: [Ph 2 Mg(dx) 3 ] (3-Ph). In the structure types 1', 1.5, and 2, the magnesium atom exhibits the coordination number 4, whereas pentacoordinate metal atoms are observed in types 3 and 1.5'. The structure type 2' is realized for [(Ph-C C) 2 Mg(dx) 2 ] 1 (2'-C 2 Ph), [MgCl 2 (dx) 2 ] 1 (2'-Cl), and [MgBr 2 (dx) 2 ] 1 (2'-Br) with hexacoordinate metal atoms. The solubility of the dioxane adducts in common organic solvents strongly depends on the degree of aggregation with the solubility decreasing from molecular to strand to layer structures.[a] Dr.Scheme 2. Dioxane method to shift the Schlenk equilibrium of organylmagnesium halides toward soluble [R 2 Mg(dx) n ] and insoluble [MgX 2 (dx) 2 ] 1 by substitution of the Lewis base L (e.g., diethyl ether or thf) by 1,4-dioxane (dx).Scheme 3. Structural diversity of hitherto known 1,4-dioxane adducts of diorganylmagnesium complexes authenticated by X-ray crystal-structure determinations.

show abstract

“…We interpret these observations in the sense that smaller THF complexes form in THF solution which are responsible for the solubility in this solvent. In similarity to the magnesium chemistry even monomeric molecules such as [(thf) 2 2 ] and dimeric [(thf)Mg(p-Tol) 2 ] 2 were found at the same time in one crystal [22]. The bidentate chelate base DME mainly leads to the formation of mononuclear complexes [(dme)MnPh 2 ].…”

Section: Epr Propertiesmentioning

confidence: 97%

Reinvestigation of arylmanganese chemistry – Synthesis and molecular structures of [(thf)4Mg(μ-Cl)2Mn(Br)Mes], [Mes(thf)Mn(μ-Mes)]2, and (MnPh2)∞ (Ph=C6H5; Mes= mesityl, 2,4,6-Me3C6H2)

Fischer

Görls

Friedrich

et al. 2009

Journal of Organometallic Chemistry

View full text Add to dashboard Cite

The coordination modes of simple diarylmagnesium species: Some representative X-ray crystal structures

Cited by 48 publications

References 22 publications

Syntheses, Reactivity and DFT Studies of Group 2 and Group 12 Metal Complexes of Tris(pyrazolyl)methanides Featuring “Free” Pyramidal Carbanions

Syntheses, Reactivity and DFT Studies of Group 2 and Group 12 Metal Complexes of Tris(pyrazolyl)methanides Featuring “Free” Pyramidal Carbanions

Structure–Solubility Relationship of 1,4‐Dioxane Complexes of Di(hydrocarbyl)magnesium

Reinvestigation of arylmanganese chemistry – Synthesis and molecular structures of [(thf)4Mg(μ-Cl)2Mn(Br)Mes], [Mes(thf)Mn(μ-Mes)]2, and (MnPh2)∞ (Ph=C6H5; Mes= mesityl, 2,4,6-Me3C6H2)

Contact Info

Product

Resources

About