Organomagnesium chemistry

Last updated

Organomagnesium chemistry, a subfield of organometallic compounds, refers to the study of magnesium compounds that contains Mg-C bonds. Magnesium is the second element in group 2 (alkaline earth metals), and the ionic radius of Mg2+ is 86 pm, which is larger than Be2+ (59 pm) and smaller than the heavier alkaline earth metal dications (Ca2+ 114 pm, Sr2+ 132 pm, Ba2+ 149 pm), [1] in accordance with periodic trends. Magnesium is less covalent compared to beryllium, and the radius is not large enough for accommodating large number of ligands compared to calcium, strontium and barium. Thus, organomagnesium compounds exhibit unique structure and reactivity in group 2. [2]

Contents

From the perspective of applications, the Grignard reagents are the most important type of organomagnesium compound. [3] They are widely used in synthetic chemistry, especially in organic synthesis, as a robust source of carbanion. Most other directions in organomagnesium chemistry are mainly of academic interest. [4] Organomagnesium compounds are usually colorless. They are highly reactive toward air: water resulting on protonolysis, O2 giving peroxides and alkoxides, and CO2 givie carboxylates.

Carbon as anionic σ-ligand

Grignard reagents

Discovered by Victor Grignard at the university of Lyon in 1900, [5] compounds with empirical formula RMgX (R = carbanion, X = Cl, Br, I) are known as Grignard reagents. They are widely used in organic synthesis. Grignard reagents are a common source of carbanion equivalents, which can be used to perform nucleophilic addition, substitution, transmetalation, and metal-halogen exchange reactions. The first crystal structure of Grignard reagents was reported by Guggenberger and Rundle in 1964, [6] [7] from a crystalline EtMgBr(THF)2 (Et = ethyl, THF = tetrahydrofuran). The Mg-C bond length was found to be 2.15(2) Å, which is about the sum of covalent radii of magnesium (141(7) pm) and carbon (76(1) pm at sp3 hybridization). [8]

Grignard reagents are dynamic in solution. The R and X groups are exchanged between magnesium centers. Via the Schlenk equilibrium, RMgX, MgR2, and MgX2 equilibrate as well. These equilibria are relevant to the reactivity of Grignard reagents. [9]

General scheme of dimerization of Grignard reagents and Schlenk equilibrium Organomagnesium Figure 1.png
General scheme of dimerization of Grignard reagents and Schlenk equilibrium

Magnesium alkyls, alkynyls, and aryls

Structure of dimethylmagnesium. Me2Mg.png
Structure of dimethylmagnesium.

Dialkylmagnesium is a fundamental type of organomagnesium compound. Such compounds can be prepared from Grignard reagents, via precipitation of magnesium halide. [11] Solid state dialkylmagnesium forms one-dimensional chains via Mg-C-Mg 3c-2e bonds, and the Mg-C bond length is 2.24(3) Å in dimethylmagnesium (Me2Mg)n, which is about 10 pm longer than the terminal alkyl-Mg bonds (e.g. 2.15(2) Å in EtMgBr(THF)2). Dialkylmagnesium compounds can prepared by treating magnesium hydride with alkenes: [12]

2 RCH=CH2 + MgH2 → Mg(C2H4R)2

Many simple homoleptic organomagnesium species are known. Examples include [Mg2(CH3)6]2−, [Mg(C6H5)4]2−, [13] and [Mg2(C6H5)6]2−. [14] Illustrating the use of salt metathesis reaction as a synthesis route, the phenylene complex [C6H4Mg(thf)]4 was prepared from C6H4Li2 and magnesium bromide: [15]

4 C6H4Li2 + 4 MgBr2 + 4 thf → [Mg(C6H4)thf]4 + 8 LiBr

[16] Illustrative of an alkynyl ("acetylide") complex is [Mg(C≡CC6H5)4]2−. Such species are relatively easily generated reflecting the diminished basicity of the "acetylide anion" relative to the alkyl carbanions. [17] [18]

Carbomagnesiation is the addition of C-Mg bonds across C≡C bonds. The process typically employs a catalyst and proceeds via the intermediacy of vinyl-Mg species: [19]

2 RC≡CR + RMgX → R2C=CR−C(R)=CR(MgBr

Mixed metal derivatives

Structure of MgAl2(CH3)8 MgAl2Me8.svg
Structure of MgAl2(CH3)8
Ni(C2H4)2Mg(CH3)2(tmeda). Color code: purple = N, Ni; turquoise = Mg; gray = C. CSD CIF GAYTOP.png
Ni(C2H4)2Mg(CH3)2(tmeda). Color code: purple = N, Ni; turquoise = Mg; gray = C.

Being electron-rich, diorganomagnesium compounds function as ligands. With alkaline metals, they forms a variety of "ate complexes". [22] [23] In this way very simple compounds can be prepared such as Mg(CH2C6H5)4Li(tmeda)]−, featuring tetrabenzylmagnesium bound via two bridging methyl ligands to a Li(tmeda)+ center. [24] This style of work often utilizes tetramethylethylenediamine (tmeda), an aprotic bidentate ligand that has a high affinity for alkali and alkaline earth metals.

Treating dimethylmagnesium with trimethylaluminium gives the neutral Al2Mg(CH3)8. [20] Similarly, treating dimethylmagnesium-tmeda with the nickel(0) ethylene complex Ni(C2H4)3 gives the neutral (C2H4)2Ni(μ−CH3)Mg(CH3)(tmeda), with displacement of one ethylene ligand. [21]

Magnesium anthracene

Synthesis of magnesium anthracene. Organomagnesium Figure 9 (cropped).png
Synthesis of magnesium anthracene.

Magnesium anthracene was first prepared by Ramsden in 1965 using a THF suspension of magnesium and anthracene. [25] Subsequent work led to the isolation of the soluble derivative [(C14H10)Mg(THF)3]. According to X-ray crystallography, the Mg-C9 and Mg-C10 distances are 2.225(1) Å]. [26] The structural results show that magnesium anthracene can be treated as an magnesium alkyl. It is a particularly versatile reagent.

Derivatives of magnesium anthracene have been described. [27]

In terms of its reactivity, [(C14H10)Mg(THF)3] behaves as the equivalent of [C14H10]2- . The two negative charges localized on C9 and C10. It thus act as nucleophile to give functionalized anthracene or 9,10-dihydroanthracene derivatives. [28] Magnesium anthracene reacts with arylphosphinous chlorides to give dibenzo-7λ3-phosphanorbornadiene (RPC14H10), which can be used as phosphinidene transfer reagent. [29]

N-heterocyclic carbene complexes

Early example of neutral magnesium-NHC complex Organomagnesium Figure 4 (cropped).png
Early example of neutral magnesium-NHC complex

The first characterized N-heterocyclic carbene (NHC) complex of magnesium, [(IMes)MgEt2]2 are synthesized by simply mixing the stable carbene with diethylmagnesium. [30] In [(IMes)MgEt2]2 the Mg-C(IMes) bond length was found to be 2.279(3) Å, which is significantly longer than the terminal Mg-C(Et) bond of 2.133(4) Å.

The NHC adduct of MgCp*2 (Cp* = pentamethylcyclopentadienyl) features one η5- and one η3-Cp* ligands. [31] NHCs with side arms were also explored. Related examples are known. [32] and the magnesium complex using NHC with phenol arms were synthesized and characterized. [33]

NHC's stabilize cationic alkyl magnesium complexes [LMgMe(THF)2]+ BPh4− (L = IMes, IPr). [34] The synthesis proceeds through an dimeric intermediate with two μ2-Me bridges. In [(IPr)MgMe(THF)2]+, the Mg-C(IPr) distance was found to be 2.2224(13) Å, which is slightly shorter than the distance in neutral NHC complexes. L2MgMeBr and [L3MgMe]+Br− (L = 1,3,4,5-tetramethylimidazol-2-ylidene) exist in equilibrium in d5-bromobenzene solution, [35] showing the substitution is facile despite its being endothermic.

Equilibrium between neutral and cationic magnesium-NHC complexes. Organomagnesium Figure 6.png
Equilibrium between neutral and cationic magnesium-NHC complexes.

Carbon as π-ligand

Cylopentadienyl complexes

Dicyclopentadienyl (Cp) magnesium or magnesocene (Cp2Mg) was first characterized in 1954 by Wilkinson and Cotton, [36] and later crystal structure analysis [37] [38] shows that it features a 5-fold symmetry with two η5-cyclopentadienyl ligands. MgCp2 has an average Mg-C distance of 2.304(8) Å an average C-C distance of 1.39(2) Å, which is in agreement with a later gas-phase diffraction study. [39] For comparison, in ferrocene the Fe-C distance is 2.04(1) Å and the C-C distance is 1.40(2) Å. Magnesocene derivatives generally adopt the ideal structures with staggered parallel Cp rings, though introducing large steric hindrance may distort the geometry, such as [{1,2,4-(Me3Si)3C5H2}2Mg] which has slightly bent sandwich structure. [40]

25Mg-NMR spectroscopy suggested the Mg-Cp interaction has significant covalent character. [41] However, because of lacking (n-1)d orbitals and back bonding, [42] the Mg-Cp interaction is weak, enabling cyclopentadienyl magnesium complexes to serve as Cp− precursor. For example, in the following reaction Cp2Mg transfers two Cp− ligands to synthesize the [MnCp3]− anion: [43]

Synthesizing the [MnCp3] anion from Cp2Mg and Cp2Mn Organomagnesium Figure 8.png
Synthesizing the [MnCp3] anion from Cp2Mg and Cp2Mn

Adding ligands to magnesocene derivatives gives bent Cp2MgL species, and the bonding modes of the cyclopentadiene are sensitive to the changes in the coordination environment. [31] In [(C5Me4H)2MgL] (L = 1,3-di-iso-propyl-4,5-dimethylimidazol-2-ylidene), [44] one of the C5Me4H ligand is slipped by 0.807 Å from the center, which makes difference of 0.69 Å between the shortest and the longest Mg-C distance on the ligand. Thus the complex can be described as [(η5-C5Me4H)(η3-C5Me4H)MgL].


Magnesium complexes with neutral π ligands

Magnesium binds alkenes, alkynes, and arenes relucantly. The low affinity for main group elements for such ligands is well established. The trend is illustrated by structural studies on Mg-allyl species, which fail to reveal interactions between Mg and the pi-system. [45]

Mg does bind to alkynes and arenes in [(Dipp-NacNac)Mg(EtC≡CEt)][B(C6F5)4] and [(Dipp-NacNac)Mg(η3-C6H6)][B(C6F5)4] (Dipp-Nacnac = [HC{C(Me)NDipp}2]−). [46] In the alkyne complex the two Mg-C distances are 2.480(2) and 2.399(2) Å, and in the arene complex the shortest Mg-C bond length is 2.520(2) Å. [47] [48] The first intramolecular Mg-alkene complex is [(Dipp-NacNac)Mg(H2C=CEt2)][B(C6F5)4], Mg is closer to the terminal methylene with Mg-C distance of 2.338(2) Å, and the longer Mg-C distance is 2.944(5) Å. [49] The Mg-alkene interactions, which are long, are described as ion-induced dipole interactions, and the large asymmetry in the 2-ethylbutene complex should be attributed to charge distribution on the two sp2 carbon atoms. [50] [49] [51]

Synthesis of cationic magnesium-p complexes using Dipp-NacNac scaffold Organomagnesium Figure 11.png
Synthesis of cationic magnesium-π complexes using Dipp-NacNac scaffold

Further examples

Organomagnesium Figure 10 (cropped).png
Organomagnesium Figure 12 (cropped).png
Organomagnesium Figure 2 (cropped).png
Mg--dibenzo[b,f]azepinate) fragment [50] Boratabenzene-Mg complex [52] [(2,6-Et2C6H3)2Mg]2 [53]

See also

References

  1. ↑ Shannon, R. D. (1976-09-01). "Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides". Acta Crystallographica Section A. 32 (5): 751–767. Bibcode:1976AcCrA..32..751S. doi:10.1107/S0567739476001551.
  2. ↑ Hill, Michael S.; Liptrot, David J.; Weetman, Catherine (2016). "Alkaline earths as main group reagents in molecular catalysis". Chemical Society Reviews. 45 (4): 972–988. doi:10.1039/C5CS00880H. PMID   26797470.
  3. ↑ Seyferth, Dietmar (2009-03-23). "The Grignard Reagents". Organometallics. 28 (6): 1598–1605. doi:10.1021/om900088z.
  4. ↑ Seeger, Margarete; Otto, Walter; Flick, Wilhelm; Bickelhaupt, Friedrich; Akkerman, Otto S. (2000). "Magnesium Compounds". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a15_595. ISBN   3-527-30673-0.
  5. ↑ Grignard, Victor (1990). "Sur quelques nouvelles combinaisons organométalliques du magnésium et leur application à des synthèses d'alcools et d'hydrocarbures". Comptes rendus de l'Académie des Sciences. 130: 1322–1324.
  6. ↑ Guggenberger, Lloyd J.; Rundle, R. E. (1964). "The Structure of Ethylmagnesium Bromide Dietherate. An X-Ray Diffraction Study" . Journal of the American Chemical Society. 86 (23): 5344–5345. Bibcode:1964JAChS..86.5344G. doi:10.1021/ja01077a068.
  7. ↑ Guggenberger, L. J.; Rundle, R. E. (1968). "Crystal structure of the ethyl Grignard reagent, ethylmagnesium bromide dietherate" . Journal of the American Chemical Society. 90 (20): 5375–5378. Bibcode:1968JAChS..90.5375G. doi:10.1021/ja01022a007.
  8. ↑ Cordero, Beatriz; Gómez, Verónica; Platero-Prats, Ana E.; Revés, Marc; Echeverría, Jorge; Cremades, Eduard; Barragán, Flavia; Alvarez, Santiago (2008). "Covalent radii revisited". Dalton Transactions (21): 2832–2838. doi:10.1039/b801115j. PMID   18478144.
  9. ↑ Peltzer, Raphael Mathias; Gauss, Jürgen; Eisenstein, Odile; Cascella, Michele (2020-02-12). "The Grignard Reaction – Unraveling a Chemical Puzzle". Journal of the American Chemical Society. 142 (6): 2984–2994. Bibcode:2020JAChS.142.2984P. doi:10.1021/jacs.9b11829. hdl: 10852/83918 . PMID   31951398.
  10. ↑ Stuhl, Christoph; Anwander, Reiner (2018). "Dimethylmagnesium revisited". Dalton Transactions. 47 (36): 12546–12552. doi:10.1039/C8DT01542B. PMID   29790529.
  11. ↑ Weiss, E. (1964). "Die kristallstruktur des dimethylmagnesiums" . Journal of Organometallic Chemistry. 2 (4): 314–321. doi:10.1016/S0022-328X(00)82217-2.
  12. ↑ Bogdanović, Borislav (1985). "Catalytic Synthesis of Organolithium and Organomagnesium Compounds and of Lithium and Magnesium Hydrides—Applications in Organic Synthesis and Hydrogen Storage". Angewandte Chemie International Edition in English. 24 (4): 262–273. doi:10.1002/anie.198502621.
  13. ↑ Viebrock, Heiko; Behrens, Ulrich; Weiss, Erwin (1994). "A Novel Organomagnesium Compound Consisting of Two Triple-Decker Cations [LMG(μ-Me(3)MGL]+ and an Octamethyltrimagnesate Anion: [{Me2Mg(μ-Me)2}2Mg]2−". Angewandte Chemie International Edition in English. 33 (12): 1257–1259. doi:10.1002/anie.199412571.
  14. ↑ Thoennes, Detlef; Weiss, Erwin (1978). "Über Metallalkyl- und -aryl-Verbindungen, XXII: Darstellung und Kristallstruktur von Bis[( N , N , N ′, N ′-tetramethylethylendiamin)lithium]-[di-μ-phenyl-bis(diphenylmagnesat)], [Li(Me2NCH2CH2NMe2)]2[Ph2MgPh2MgPh2], ein erster at-Komplex mit Phenyl-Brücken". Chemische Berichte. 111 (11): 3726–3731. doi:10.1002/cber.19781111117.
  15. ↑ Tinga, Marcus A. G. M.; Akkerman, Otto S.; Bickelhaupt, Friedrich; Horn, Ernst; Spek, Anthony L. (1991). "o-Phenylenemagnesium tetramer: The First Organomagnesium cluster". Journal of the American Chemical Society. 113 (9): 3604–3605. Bibcode:1991JAChS.113.3604T. doi:10.1021/ja00009a064.
  16. ↑ Liu, Yuesheng; Wang, Lijun; Deng, Liang (2016). "Selective Double Carbomagnesiation of Internal Alkynes Catalyzed by Iron-N-Heterocyclic Carbene Complexes: A Convenient Method to Highly Substituted 1,3-Dienyl Magnesium Reagents". Journal of the American Chemical Society. 138 (1): 112–115. Bibcode:2016JAChS.138..112L. doi:10.1021/jacs.5b12522. PMID   26713433.
  17. ↑ Schubert, Bernd; Weiss, Erwin (1984). "Über Metallalkyl- und -aryl-Verbindungen, XXXII. Darstellung und Kristallstrukturen zweier neuer Lithium-Magnesate mit Phenylethinyl- BZW. Benzyl-Liganden: Li2[(PhC≡C)3Mg(tmeda)]2 und [Li(tmeda)2]- [(tmeda)LiBzl2MgBzL2]". Chemische Berichte. 117: 366–375. doi:10.1002/cber.19841170127.
  18. ↑ Schumann, Herbert; Steffens, Alexandra; Hummert, Markus (2009). "Synthese, Röntgenstrukturanalyse und katalytische Aktivität neuer Erdalkalimetall-Alkinkomplexe". Zeitschrift für anorganische und allgemeine Chemie. 635 (6–7): 1041–1047. Bibcode:2009ZAACh.635.1041S. doi:10.1002/zaac.200900159.
  19. ↑ Liu, Yuesheng; Wang, Lijun; Deng, Liang (2016). "Selective Double Carbomagnesiation of Internal Alkynes Catalyzed by Iron-N-Heterocyclic Carbene Complexes: A Convenient Method to Highly Substituted 1,3-Dienyl Magnesium Reagents". Journal of the American Chemical Society. 138 (1): 112–115. Bibcode:2016JAChS.138..112L. doi:10.1021/jacs.5b12522. PMID   26713433.
  20. 1 2 Atwood, J. L.; Stucky, Galen D. (1969). "Stereochemistry of polynuclear compounds of the main group elements. VII. Structure of Octamethyldialuminummonomagnesium". Journal of the American Chemical Society. 91 (10): 2538–2543. Bibcode:1969JAChS..91.2538A. doi:10.1021/ja01038a025.
  21. 1 2 Kaschube, Wilfried; Pörschke, Klaus-Richard; Angermund, Klaus; Krüger, Carl; Wilke, Günther (1988). "Zur Lewis-Acidität von Nickel(0), X. Diorganylmagnesium-Komplexe von Nickel(0): (TMEDA)MgCH 3(μ-CH3)Ni(C2H4)2". Chemische Berichte. 121 (11): 1921–1929. doi:10.1002/cber.19881211108.
  22. ↑ Robertson, Stuart D.; Uzelac, Marina; Mulvey, Robert E. (2019-07-24). "Alkali-Metal-Mediated Synergistic Effects in Polar Main Group Organometallic Chemistry". Chemical Reviews. 119 (14): 8332–8405. doi:10.1021/acs.chemrev.9b00047. PMID   30888154.
  23. ↑ Mulvey, Robert E. (2006-02-01). "Modern Ate Chemistry: Applications of Synergic Mixed Alkali-Metal−Magnesium or −Zinc Reagents in Synthesis and Structure Building". Organometallics. 25 (5): 1060–1075. doi:10.1021/om0510223.
  24. ↑ Schubert, Bernd; Weiss, Erwin (1984). "Über Metallalkyl- und -aryl-Verbindungen, XXXII. Darstellung und Kristallstrukturen zweier neuer Lithium-Magnesate mit Phenylethinyl- BZW. Benzyl-Liganden: Li2[(PhC≡C)3Mg(tmeda)]2 und [Li(tmeda)2]- [(tmeda)LiBzl2MgBzL2]". Chemische Berichte. 117: 366–375. doi:10.1002/cber.19841170127.
  25. ↑ Ramsden, H. E. Magnesium and Tin Derivatives of Fused ring Hydrocarbons and the Preparation Thereof. US3354190A, November 21, 1967. https://patents.google.com/patent/US3354190A/en (accessed 2024-11-19).
  26. ↑ Engelhardt, Lutz M.; Harvey, Stephen; Raston, Colin L.; White, Allan H. (1988). "Organo-Magnesium Reagents: the Crystal Structures of [Mg(anthracene)(THF)3] and [Mg(triphenylmethyl)Br(OEt2)2]" . Journal of Organometallic Chemistry. 341 (1–3): 39–51. doi:10.1016/0022-328X(88)89061-2.
  27. ↑ Bogdanović, Borislav; Janke, Nikolaus; Krüger, Carl; Mynott, Richard; Schlichte, Klaus; Westeppe, Uwe (1985). "Synthesis and Structure of 1,4-Dimethylanthracenemagnesium·3thf and μ-Trichlorodimagnesium·6thf(1+) Anthracenide" . Angewandte Chemie International Edition in English. 24 (11): 960–961. doi:10.1002/anie.198509601.
  28. ↑ Bogdanovic, Borislav (1988-07-01). "Magnesium anthracene systems and their application in synthesis and catalysis". Accounts of Chemical Research. 21 (7): 261–267. doi:10.1021/ar00151a002.
  29. ↑ Velian, Alexandra; Cummins, Christopher C. (2012-08-29). "Facile Synthesis of Dibenzo-7λ3 -phosphanorbornadiene Derivatives Using Magnesium Anthracene". Journal of the American Chemical Society. 134 (34): 13978–13981. doi:10.1021/ja306902j. PMID   22894133.
  30. 1 2 Arduengo, Anthony J.; Dias, H.V.Rasika; Davidson, Fredric; Harlow, R.L. (1993). "Carbene Adducts of Magnesium and Zinc" . Journal of Organometallic Chemistry. 462 (1–2): 13–18. doi:10.1016/0022-328X(93)83336-T.
  31. 1 2 Arduengo, Anthony J.; Davidson, Fredric; Krafczyk, Roland; Marshall, William J.; Tamm, Matthias (1998-07-01). "Adducts of Carbenes with Group II and XII Metallocenes†". Organometallics. 17 (15): 3375–3382. doi:10.1021/om980438w.
  32. ↑ Mungur, Shaheed A.; Liddle, Stephen T.; Wilson, Claire; Sarsfield, Mark J.; Arnold, Polly L. (2004). "Bent metal carbene geometries in amido N-heterocyclic carbene complexes". Chemical Communications (23): 2738–2739. doi:10.1039/b410074c. PMID   15568093.
  33. ↑ Zhang, Dao; Kawaguchi, Hiroyuki (2006-10-01). "Deprotonation Attempts on Imidazolium Salt Tethered by Substituted Phenol and Construction of Its Magnesium Complex by Transmetalation". Organometallics. 25 (22): 5506–5509. doi:10.1021/om060691t.
  34. ↑ Bruyere, Jean-Charles; Gourlaouen, Christophe; Karmazin, Lydia; Bailly, Corinne; Boudon, Corinne; Ruhlmann, Laurent; De Frémont, Pierre; Dagorne, Samuel (2019-07-22). "Synthesis and Characterization of Neutral and Cationic Magnesium Complexes Supported by NHC Ligands". Organometallics. 38 (14): 2748–2757. doi:10.1021/acs.organomet.9b00304.
  35. 1 2 Obi, Akachukwu D.; Machost, Haleigh R.; Dickie, Diane A.; Gilliard, Robert J. (2021-08-16). "A Thermally Stable Magnesium Phosphaethynolate Grignard Complex". Inorganic Chemistry. 60 (16): 12481–12488. doi:10.1021/acs.inorgchem.1c01700. PMID   34346670.
  36. ↑ Wilkinson, Geoffrey; Cotton, F. Albert CYCLOPENTADIENYL COMPOUNDS OF MANGANESE AND MAGNESIUM; United States, 1954. https://www.osti.gov/biblio/4371627.
  37. ↑ Weiss, E.; Fischer, E. O. (1955). "Zur Kristallstruktur der Di-cyclopentadienyl-verbindungen des zweiwertigen Magnesiums und Vanadins" . Zeitschrift für anorganische und allgemeine Chemie. 278 (3–4): 219–224. doi:10.1002/zaac.19552780313.
  38. ↑ Bünder, Wolfgang; Weiss, Erwin (1975). "Verfeinerung der Kristallstruktur von Dicyclopentadienylmagnesium, (η-C5H5)2Mg" . Journal of Organometallic Chemistry. 92 (1): 1–6. doi:10.1016/S0022-328X(00)91094-5.
  39. ↑ Haaland, Arne; Lusztyk, Janusz; Brunvoll, Jon; Starowieyski, Kazimierz B. (1975). "On the Molecular Structure of Dicyclopentadienylmagnesium" . Journal of Organometallic Chemistry. 85 (3): 279–285. doi:10.1016/S0022-328X(00)80301-0.
  40. ↑ Morley, C. P.; Jutzi, P.; Krueger, C.; Wallis, J. M. (1987). "[.eta.5-Tris(trimethylsilyl)cyclopentadienyl]magnesium Compounds: Syntheses and Structures" . Organometallics. 6 (5): 1084–1090. doi:10.1021/om00148a029.
  41. ↑ Benn, Reinhard; Lehmkuhl, Herbert; Mehler, Klaus; Rufińska, Anna (1984). "25 Mg-NMR: A Method for the Characterization of Organomagnesium Compounds, their Complexes, and Schlenk Equilibria" . Angewandte Chemie International Edition in English. 23 (7): 534–535. doi:10.1002/anie.198405341.
  42. ↑ Faegri, K.; Almlöf, J.; Lüth, H.P. (1983). "The Geometry and Bonding of Magnesocene. An Ab-Initio MO-LCAO Investigation" . Journal of Organometallic Chemistry. 249 (2): 303–313. doi:10.1016/S0022-328X(00)99429-4.
  43. 1 2 {{Cite journal| doi = 10.1039/b106366a| issue = 19| pages = 1956–1957| last1 = Bond| first1 = Andrew D.| last2 = Layfield| first2 = Richard A.| last3 = MacAllister| first3 = Judith A.| last4 = Rawson| first4 = Jeremy M.| last5 = Wright| first5 = Dominic S.| last6 = McPartlin| first6 = Mary| title = The First Observation of the [Cp3Mn]– Anion; Structures of Hexagonal [(η2-Cp)3MnK·1.5thf] and Ion-Separated [(η2-Cp)3Mn]2[Mg(thf)6]·2thf| journal = Chemical Communications| date = 2001| pmid = 12240237| url = https://xlink.rsc.org/?DOI=b106366a}
  44. ↑ Schumann, Herbert; Gottfriedsen, Jochen; Glanz, Mario; Dechert, Sebastian; Demtschuk, Jörg (2001). "Metallocenes of the Alkaline Earth metals and Their Carbene Complexes" . Journal of Organometallic Chemistry. 617–618: 588–600. doi:10.1016/S0022-328X(00)00684-7.
  45. ↑ Lichtenberg, Crispin; Spaniol, Thomas P.; Peckermann, Ilja; Hanusa, Timothy P.; Okuda, Jun (2013). "Cationic, Neutral, and Anionic Allyl Magnesium Compounds: Unprecedented Ligand Conformations and Reactivity Toward Unsaturated Hydrocarbons". Journal of the American Chemical Society. 135 (2): 811–821. Bibcode:2013JAChS.135..811L. doi:10.1021/ja310112e. PMID   23240932.
  46. 1 2 Pahl, Jürgen; Brand, Steffen; Elsen, Holger; Harder, Sjoerd (2018). "Highly Lewis acidic cationic alkaline earth metal complexes". Chemical Communications. 54 (63): 8685–8688. doi:10.1039/C8CC04083D. PMID   29892727.
  47. ↑ Pahl, Jürgen; Friedrich, Alexander; Elsen, Holger; Harder, Sjoerd (2018-09-10). "Cationic Magnesium π–Arene Complexes". Organometallics. 37 (17): 2901–2909. doi:10.1021/acs.organomet.8b00489.
  48. ↑ Friedrich, Alexander; Pahl, Jürgen; Elsen, Holger; Harder, Sjoerd (2019). "Bulky cationic β-diketiminate magnesium complexes". Dalton Transactions. 48 (17): 5560–5568. doi:10.1039/C8DT03576H. PMID   30566138.
  49. 1 2 3 Thum, Katharina; Friedrich, Alexander; Pahl, Jürgen; Elsen, Holger; Langer, Jens; Harder, Sjoerd (2021). "Unsupported Mg–Alkene Bonding". Chemistry – A European Journal. 27 (7): 2513–2522. Bibcode:2021ChEuJ..27.2513T. doi:10.1002/chem.202004716. PMC   7898539 . PMID   33197075.
  50. 1 2 Freitag, Benjamin; Elsen, Holger; Pahl, Jürgen; Ballmann, Gerd; Herrera, Alberto; Dorta, Romano; Harder, Sjoerd (2017-05-08). "s-Block Metal Dibenzoazepinate Complexes: Evidence for Mg–Alkene Encapsulation". Organometallics. 36 (9): 1860–1866. doi:10.1021/acs.organomet.7b00200.
  51. ↑ Martin, Johannes; Langer, Jens; Wiesinger, Michael; Elsen, Holger; Harder, Sjoerd. "Dibenzotropylidene Substituted Ligands for Early Main Group Metal-Alkene Bonding". European Journal of Inorganic Chemistry. 2020 (27): 2582–2595. doi:10.1002/ejic.202000524.
  52. ↑ Zheng, Xiaolai; Englert, Ulli; Herberich, Gerhard E.; Rosenplänter, Jörg (2000-12-01). "Syntheses and Structures of Mg(C5H5BMe)2, Mg(3,5-Me2C5H3BNMe2 )2, the 2,2'-Bipyridine Adduct Mg(C5H5BMe)2 (bipy), and the N-Bonded Aminoboratabenzene Species Mg(3,5-Me2C5H3BNMe2)2(THF)21". Inorganic Chemistry. 39 (25): 5579–5585. doi:10.1021/ic000575x. PMID   11151358.
  53. ↑ Wehmschulte, Rudolf. J.; Twamley, Brendan; Khan, Masood A. (2001-11-01). "Synthesis and Characterization of an Unsolvated Dimeric Diarylmagnesium Compound and Its Magnesium Iodide Byproducts". Inorganic Chemistry. 40 (23): 6004–6008. doi:10.1021/ic010513m. PMID   11681917.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.