Magnesium compounds: Classification and analysis of crystallographic and structural data (original) (raw)
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1984
MgTeO3.6H20 and MgSeOv6H20 isomorphous, Mr=307.9, 259.4, rhombohedral, R3, a=6.011 (3), 5.965(2)A, ~= 97.36 (4), 97.28(2) ° , V=211.3(1), 206.7(1)A 3, Z=l, Dx=2.42(1), 0108-2701/84/040586-04501.50 2-08(1)gcm -3, MoKt~, 2=0-71069A, p=37.4, 49.8 cm -l, F(000) = 148, 130, T= 293 K, 819, 695 diffractometer reflections, R = 0.029, 0.021. The structures are isomorphous with MgSO3.6H20. The dimen-
Crystal structures of two magnesium citrates from powder diffraction data
Acta Crystallographica Section E Crystallographic Communications
The crystal structures of magnesium hydrogen citrate dihydrate, Mg(HC6H5O7)(H2O)2, (I), and bis(dihydrogen citrato)magnesium, Mg(H2C6H5O7)2, (II), have been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. In (I), the citrate anion occurs in the trans, trans-conformation, and triply chelates to the Mg cation. In (II), the citrate anion is trans, gauche, and doubly chelates to the Mg cation. In both compounds the Mg cation coordination polyhedron is an octahedron. In (I), the MgO6 coordination polyhedra are isolated, while in (II), they share edges to form chains. Strong O—H...O hydrogen bonds are prominent in the two structures, as well as in the previously reported magnesium citrate decahydrate.
Synthesis and Structures of β-Diketoiminate Complexes of Magnesium
Zeitschrift für anorganische und allgemeine Chemie, 2001
The reaction of the b-diketoiminate lithium complex (dipp)NacNacLi´OEt 2 ((dipp)NacNac = 2-((2,6-diisopropylphenyl)amino)-4-((2,6-diisopropylphenyl)imino)-pent-2-enyl) with iPrMgCl and MgI 2 yield the corresponding (dipp)NacNacMgiPr´OEt 2 (1) and (dipp)NacNacMgI´OEt 2 (2). The reaction of 2 with NaBH 4 in diethylether gives (dipp)NacNacMg(l-H) 3 BH´OEt 2 (3). The core element of compounds 1±3 is a six-membered ring formed by N(1)±C(1)±C(2)±C(3)±N(2) and magnesium. The structures of 1 and 2 show the b-diketoiminate backbone in a boat-conformation with the tetrahedrally coordinated metal center at the prow and the opposing carbon atom at the stern. The magnesium atom in 3 is octahedrally coordinated and out of the b-diketoiminate plane.
Preparation, crystal structure, and reactivity of bis {tris(trimethylsilyl) methyl} magnesium
Journal of Organometallic Chemistry, 1994
Heating of the lithium magnesate [Li(THF)2(~-Br)zMBsiM~F)] (Tsi = (Me&C) under vacuum gives the dialkylmagnesium compound Mg(Tsi),, the first two-coordinate magnesium derivative to have been structurally characterized in the solid state. The compound is remarkably thermally stable, not decomposing (or melting) when heated to 350°C. It has a very low reactivity, failing to react in toluene with, for example, CO*, Me&Cl, Me,SiHCl, MeI, BCl, or CHsCOCl, and even with neat CH,COcI at its boiling point. I! does react, though fairly slowly, with I, in toluene to give TsiI, and more rapidly with Br, to give TsiBr, and with an excess of PhSO,Cl in toluene at 100°C to give TsiCl. It decomposes quickly in the air, and reacts readily with MeOH in toluene to give TsiH without formation of detectable amounts of the intermediate TsiMgOMe, and with 0, in toluene.
Zeitschrift für anorganische und allgemeine Chemie, 2010
The controlled hydrolysis of heteroleptic magnesium amide, LMgN(SiMe 3 ) 2 (L = CH[C(Me)N(2,6-iPr 2 C 6 H 3 )] 2 ) with water afforded the corresponding hydroxide [LMg(OH)·THF] 2 as air and moisture sensitive compound. The presence of a sterically bulky β-diketiminate ligand prevents the self-condensation reaction of this hydroxide complex. Single crystal X-ray analysis shows that the hydroxide is dimeric in the solid state. Reaction of the magnesium amide or 201 LMg(Me)·OEt 2 with LAlMe(OH) generates the heterobimetallic species containing the Mg-O-Al moiety. Additionally, the reaction of methylmagnesiumchloride with the free ligand leads to complex L'MgCl (L' = CH[Et 2 NCH 2 CH 2 N(CMe)] 2 ). As revealed by the crystal structure, L'MgCl is a solvent free monomeric magnesium chloride complex that is analogues to the Grignard reagent.
Low coordinate magnesium chemistry supported by a bulky β-diketiminate ligand
Dalton Trans., 2003
A series of magnesium() alkyl, alkoxide, carboxylate, amide and halide complexes stabilised by the bulky β-diketiminate ligand, HC(C(Me)N-2,6-i Pr 2 C 6 H 3) 2 (BDI), have been synthesised and structurally characterised. (BDI)H reacts with MgMe 2 in Et 2 O to give the four-coordinate complex (BDI)MgCH 3 (Et 2 O), 1, and in toluene to afford [(BDI)Mg(µ-CH 3)] 2 , 2. Three coordinate complexes may be accessed by increasing the size of the alkyl ligand; hence, the reaction of (BDI)H with t Bu 2 Mg yields (BDI)Mg t Bu, 3, while Li(BDI) reacts with i PrMgCl to afford (BDI)Mg i Pr, 4; a similar reaction with PhMgCl affords the diethyl ether adduct (BDI)MgPh(Et 2 O), 5. The etherates 1 and 5 may be converted into the base-free complexes, 2 and (BDI)MgPh, 6, respectively, upon heating in vacuo. The direct reaction of (BDI)H with RMgX (X = Cl or Br) results in relatively inert halide-bridged dimers of formula [(BDI)Mg(µ-X)] 2 , (X = Cl, 7; X = Br, 8). The alkylmagnesium derivatives react readily with alcohols, amines or carboxylic acids to yield alkoxide, amide and carboxylate complexes, respectively. For example, 4 reacts with i PrOH (or O 2) to form [(BDI)Mg(µ-O i Pr)] 2 , 9. Convenient one-pot synthetic procedures have been developed using commercially available Bu 2 Mg. Treatment of Bu 2 Mg with (BDI)H, followed by its reaction with MeOH, t BuOH, i Pr 2 NH, (Me 3 Si) 2 NH, MeCO 2 H or PhCO 2 H affords [(BDI)Mg(µ-OMe)] 2 , 10, [(BDI)Mg(µ-O t Bu)] 2 , 11, (BDI)Mg(N i Pr 2), 12, (BDI)Mg(NTMS 2), 13, [(BDI)Mg(µ-O 2 CMe])] 2 , 14, and [(BDI)Mg(µ-O 2 CPh)] 2 , 15, respectively. The molecular structures of complexes 4-8 and 12-15 are reported.
Angewandte Chemie International Edition, 2012
for helpful discussions, and M. Kayas, S. Schneider, and P. Smie for the technical assistance during the preparation of the manuscript. Supporting information for this article, including experimental details, quantum chemical calculations, thermodynamic investigations, and crystallographic details, is available on the WWW under
Structure of a new ternary compound with high magnesium content, so-called Gd13Ni9Mg78
Acta Materialia, 2012
The magnesium metal rich composition Gd 13 Ni 9 Mg 78 was synthesized from the elements in sealed tantalum tubes in an induction furnace. According to the X-ray diffraction, the EPMA analyses and the dark field images obtained by TEM, a new compound with a composition ranging from Gd 10-15 Ni 8-12 Mg 72-78 and low crystallinity was brought to light. In order to increase the crystallinity, different experimental conditions were investigated for numerous compounds with the initial composition Gd 13 Ni 9 Mg 78. Also, several heat treatments (from 573 K to 823 K) and cooling rates (from room temperature quenched down to 2 K/h) have been tested. The best crystallinity was obtained for the slower cooling rates ranging from 2 to 6 K/h. From the more crystallized compounds, the structure was partially deduced using the transmission electron microscopy and an average cubic structure with lattice parameter a = 4.55 Å could be assumed. A modulation along both a*and b* axis with vectors of modulation q1 = 0.42a* and q2 = 0.42b* was observed. This compound so-called Gd 13 Ni 9 Mg 78 absorbs around 3 wt% of hydrogen at 603 K, 30 bars and some fair reversibility is possible, because after the first hydrogenation, irreversible decomposition into MgH 2 , GdH 2 and NiMgH 4 has been shown. The pathway of the reaction is described herein. The powder mixture after decomposition shows an interesting kinetics for magnesium without ball milling.