Stability and Reactivity of Phenylstrontium Compounds in Solution

Abstract

Fragmentation of tetrahydrofuran (thf) and N,N,N 0 ,N 0 -tetramethylethylenediamine (tmeda) by PhSrI leads to the formation of the new organostrontium compounds [(tmeda)Sr(I)(μ-Ph) 2 -{μ-N(Me)CH 2 CH 2 NMe 2 )Sr(tmeda)], [(tmeda)Sr(I)(μ-Ph)(μ-I){μ-N(Me)CH 2 CH 2 NMe 2 )Sr(tmeda)], and [{(tmeda)Sr} 4 (μ 4 -O)(μ-I) 4 (μ-Ph) 2 ].

Halide‐Free Diarylcalcium Complexes—Syntheses, Structures, and Stability

“…The use of N,N,N′,N′‐ tetramethylethylenediamine (tmeda) disclosed that the structural analogies found for phenylcalcium iodides and calcium diiodides cannot be simply extended to the arylcalcium derivatives. While [CaI(Ph)(tmeda) 2 ]8d and [CaI 2 (tmeda) 2 ]19 are mononuclear octahedral complexes with a trans alignment of the anionic ligands, the use of an excess of bidentate TMEDA leads in the case of the diarylcalcium derivatives to the crystallization of dimers of the type [(Aryl)Ca(μ‐Aryl)(tmeda)] 2 with two terminal and two bridging aryl ligands. The coordination sphere of calcium in [(Tol)Ca(μ‐Tol)(tmeda)] 2 ( 3 ) (see Figure 2; Tol=4‐methylphenyl), and [(Ph)Ca(μ‐Ph)(tmeda)] 2 ( 4 )12 is remarkable and best described as distorted square pyramidal with the two nitrogen atoms of tmeda and the carbon atoms of the bridging aryl ligands occupying the basal and the terminal aryl ligand the apical position.…”

Alkaline and alkaline earth metals

“…144 Fragmentation of THF and TMEDA by PhSrI has been shown to lead to the formation of several new organostrontium compounds. 145 The structure and bonding of CpBeH, CpMgH and CpCaH has been investigated by means of DFT calculations. 146 Reaction of Group 2 dialkyl compounds, [M{CH(SiMe 3 ) 2 } 2 (THF)n] [M = Mg, Ca, n = 2; M = Sr, Ba, n = 3] with a bis(imino)pyridine ligand has been shown to result in deprotonation of both methyl groups attached to the imine carbon centre.…”

Organic heterobimetallic complexes of the alkaline earth metals (Ae = Ca, Sr, Ba) with tetrahedral metallate anions of three-valent metals (M = B, Al, Ga, and V)

“…49 The high alkalinity of the reaction solutions additionally indicates that the lack of aryl derivatives of strontium and barium is more related to problems of isolation but not formation of these derivatives. 50 Following this assumption, such solutions should be useful as synthetic equivalents for isolated organostrontium or organobarium derivatives.…”