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Synthesis, structure and reaction chemistry of a nucleophilic aluminyl anion

Nature volume 557, pages 92–95 (2018)Cite this article

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A Publisher Correction to this article was published on 04 June 2018

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Abstract

The reactivity of aluminium compounds is dominated by their electron deficiency and consequent electrophilicity; these compounds are archetypal Lewis acids (electron-pair acceptors). The main industrial roles of aluminium, and classical methods of synthesizing aluminium–element bonds (for example, hydroalumination and metathesis), draw on the electron deficiency of species of the type AlR3 and AlCl31,2. Whereas aluminates, [AlR4]−, are well known, the idea of reversing polarity and using an aluminium reagent as the nucleophilic partner in bond-forming substitution reactions is unprecedented, owing to the fact that low-valent aluminium anions analogous to nitrogen-, carbon- and boron-centred reagents of the types [NX2]−, [CX3]− and [BX2]− are unknown3,4,5. Aluminium compounds in the +1 oxidation state are known, but are thermodynamically unstable with respect to disproportionation. Compounds of this type are typically oligomeric6,7,8, although monomeric systems that possess a metal-centred lone pair, such as Al(Nacnac)Dipp (where (Nacnac)Dipp = (NDippCR)2CH and R = tBu, Me; Dipp = 2,6-iPr2C6H3), have also been reported9,10. Coordination of these species, and also of (η5-C5Me5)Al, to a range of Lewis acids has been observed11,12,13, but their primary mode of reactivity involves facile oxidative addition to generate Al(iii) species6,7,8,14,15,16. Here we report the synthesis, structure and reaction chemistry of an anionic aluminium(i) nucleophile, the dimethylxanthene-stabilized potassium aluminyl [K{Al(NON)}]2 (NON = 4,5-bis(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene). This species displays unprecedented reactivity in the formation of aluminium–element covalent bonds and in the C–H oxidative addition of benzene, suggesting that it could find further use in both metal–carbon and metal–metal bond-forming reactions.

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Fig. 1: Syntheses of the potassium aluminyl compound [K{Al(NON)}]2 and the dialane [Al(NON)]2.
Fig. 2: Geometric and electronic structure of [K{Al(NON)}]2.
Fig. 3: Exploitation of the aluminium-centred nucleophilic reactivity of [K{Al(NON)}]2.
Fig. 4: Molecular structures of an aluminium alkyl and a magnesium aluminyl compound formed via reactions of [K{Al(NON)}]2, as determined by X-ray crystallography.

Change history

  • 04 June 2018

    In Fig. 1 of this Letter, the hydrogen (H) atoms attached to each of the two nitrogen (N) atoms in the chemical structure of (NON)H2 were inadvertently missing. The original figure has been corrected online.

References

  1. Aldridge, S. & Downs, A. J. (eds) The Group 13 Metals Aluminium, Gallium, Indium and Thallium: Chemical Patterns and Peculiarities (Wiley, Chichester, 2011).

  2. Helmboldt, O. et al. Ullmann’s Encyclopedia of Industrial Chemistry: Aluminum Compounds, Inorganic (Wiley VCH, Weinheim, 2007).

  3. Lappert, M., Protchenko, A., Power, P. & Seeber, A. Metal Amide Chemistry (Wiley, Chichester, 2009).

  4. Rappoport, Z. & Marek, I. (eds) The Chemistry of Organolithium Compounds (Wiley–Blackwell, Chichester, 2004).

  5. Segawa, Y., Yamashita, M. & Nozaki, K. Boryllithium: isolation, characterization, and reactivity as a boryl anion. Science 314, 113–115 (2006).

    Article  ADS  CAS  Google Scholar 

  6. Dohmeier, C., Loos, D. & Schnöckel, H. Aluminum(i) and gallium(i) compounds: syntheses, structures, and reactions. Angew. Chem. Int. Ed. 35, 129–149 (1996).

    Article  CAS  Google Scholar 

  7. Nagendran, S. & Roesky, H. The chemistry of aluminum(i), silicon(ii) and germanium(ii). Organometallics 27, 457–492 (2008).

    Article  CAS  Google Scholar 

  8. Jones, C. & Stasch, A. in The Group 13 Metals Aluminium, Gallium, Indium and Thallium: Chemical Patterns and Peculiarities (eds Aldridge, S. & Downs, A. J.) 285–341 (Wiley, Chichester, 2011).

  9. Cui, C. et al. Synthesis and structure of a monomeric aluminum(i) compound [{HC(CMeNAr)2}Al] (Ar = 2,6-iPr2C6H3): a stable aluminum analogue of a carbene. Angew. Chem. Int. Ed. 39, 4274–4276 (2000).

    Article  CAS  Google Scholar 

  10. Li, X., Cheng, X., Song, H. & Cui, C. Synthesis of HC[(CBut)(NAr)]2Al (Ar = 2,6-Pri 2C6H3) and its reaction with isocyanides, a bulky azide, and H2O. Organometallics 26, 1039–1043 (2007).

    Article  CAS  Google Scholar 

  11. Linti, G. & Schnöckel, H. Low valent aluminium and gallium compounds — structural variety and coordination modes to transition metal fragments. Coord. Chem. Rev. 206–207, 285–319 (2000).

    Article  Google Scholar 

  12. Asay, M., Jones, C. & Driess, M. N-heterocyclic carbene analogues with low-valent group 13 and group 14 elements: syntheses, structures, and reactivities of a new generation of multitalented ligands. Chem. Rev. 111, 354–396 (2011).

    Article  CAS  Google Scholar 

  13. González-Gallardo, S., Bollermann, T., Fischer, R. A. & Murugavel, R. Cyclopentadiene based low-valent group 13 metal compounds: ligands in coordination chemistry and link between metal rich molecules and intermetallic materials. Chem. Rev. 112, 3136–3170 (2012).

    Article  Google Scholar 

  14. Chu, T., Korobkov, I. & Nikonov, G. I. Oxidative addition of σ bonds to an Al(i) center. J. Am. Chem. Soc. 136, 9195–9202 (2014).

    Article  CAS  Google Scholar 

  15. Crimmin, M. R., Butler, M. J. & White, A. J. P. Oxidative addition of carbon–fluorine and carbon–oxygen bonds to Al(i). Chem. Commun. 51, 15994–15996 (2015).

    Article  CAS  Google Scholar 

  16. Chu, T., Boyko, Y., Korobkov, I. & Nikonov, G. I. Transition metal-like oxidative addition of C–F and C–O bonds to an aluminum(i) center. Organometallics 34, 5363–5365 (2015).

    Article  CAS  Google Scholar 

  17. Sundermann, A., Reiher, M. & Schoeller, W. W. Isoelectronic Arduengo-type carbene analogues with the group IIIa elements boron, aluminum, gallium, and indium. Eur. J. Inorg. Chem. 1998, 305–310 (1998).

    Article  Google Scholar 

  18. Tuononen, H. M., Roesler, R., Dutton, J. L. & Ragogna, P. J. Electronic structures of main-group carbene analogues. Inorg. Chem. 46, 10693–10706 (2007).

    Article  CAS  Google Scholar 

  19. Westrum, L. J. & Rakita, P. E. (eds) Handbook of Grignard Reagents 2nd edn (CRC Press, Boca Raton, 2015).

  20. Uhl, W. Organoelement compounds possessing Al–Al, Ga–Ga, In–In, and Tl–Tl single bonds. Adv. Organomet. Chem. 51, 53–108 (2004).

    Article  CAS  Google Scholar 

  21. Twamley, B. & Power, P. P. Synthesis of the square-planar gallium species K2[Ga4(C6H3-2,6-Trip2)2] (Trip = C6H2-2,4,6-iPr3): the role of aryl–alkali metal ion interactions in the structure of gallium clusters. Angew. Chem. Int. Ed. 39, 3500–3503 (2000).

    Article  CAS  Google Scholar 

  22. Cordero, B. et al. Covalent radii revisited. Dalton Trans. 21, 2832–2838 (2008).

  23. Bakewell, C., Ward, B. J., White, A. J. P. & Crimmin, M. R. A combined experimental and computational study on the reaction of fluoroarenes with Mg–Mg, Mg–Zn, Mg–Al and Al–Zn bonds. Chem. Sci. 9, 2348–2356 (2018).

    Article  CAS  Google Scholar 

  24. Green, S. P., Jones, C. & Stasch, A. Stable magnesium(i) compounds with Mg–Mg bonds. Science 318, 1754–1757 (2007).

    Article  ADS  CAS  Google Scholar 

  25. Martínez-Martínez, A. J., Kennedy, A. R., Mulvey, R. E. & O’Hara, C. T. Directed ortho-meta′- and meta-meta′-dimetalations: a template base approach to deprotonation. Science 346, 834–837 (2014).

    PubMed  Google Scholar 

  26. Ohsato, T. et al. A potassium diboryllithate: synthesis, bonding properties, and the deprotonation of benzene. Angew. Chem. Int. Ed. 55, 11426–11430 (2016).

    Article  CAS  Google Scholar 

  27. Cruz, C. A., Emslie, D. J. H., Harrington, L. E., Britten, J. F. & Robertson, C. M. Extremely stable thorium(iv) dialkyl complexes supported by rigid tridentate 4,5-bis(anilido)xanthene and 2,6-bis(anilidomethyl)pyridine ligands. Organometallics 26, 692–701 (2007).

    Article  CAS  Google Scholar 

  28. Bonyhady, S. J. et al. β-diketiminate-stabilized magnesium(i) dimers and magnesium(ii) hydride complexes: synthesis, characterization, adduct formation, and reactivity studies. Chem. Eur. J. 16, 938–955 (2010).

    Article  CAS  Google Scholar 

  29. Zakharkin, L. I. & Gavrilenko, V. V. Mutual conversions in the alumohydrides of lithium, sodium, and potassium. Russ. Chem. Bull. 11, 1076–1078 (1962).

    Article  Google Scholar 

  30. Cosier, J. & Glazer, A. M. A nitrogen-gas-stream cryostat for general X-ray diffraction studies. J. Appl. Crystallogr. 19, 105–107 (1986).

    Article  CAS  Google Scholar 

  31. CrysAlisPro v.1.171.35.8 (Agilent Technologies, 2011).

  32. Sheldrick, G. M. SHELX-2014 (2014).

  33. Hübschle, C. B., Sheldrick, G. M. & Dittrich, B. ShelXle: a Qt graphical user interface for SHELXL. J. Appl. Crystallogr. 44, 1281–1284 (2011).

    Article  Google Scholar 

  34. Frisch, M. J. et al. Gaussian 09 Rev. D.01, (Gaussian Inc., 2009).

  35. Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865–3868 (1996).

    Article  ADS  CAS  Google Scholar 

  36. Perdew, J. P., Ernzerhof, M. & Burke, K. Rationale for mixing exact exchange with density functional approximations. J. Chem. Phys. 105, 9982–9985 (1996).

    Article  ADS  CAS  Google Scholar 

  37. Adamo, C. & Barone, V. Toward reliable density functional methods without adjustable parameters: the PBE0 model. J. Chem. Phys. 110, 6158–6170 (1999).

    Article  ADS  CAS  Google Scholar 

  38. Schäfer, A., Huber, C. & Ahlrichs, R. Fully optimized contracted Gaussian basis sets of triple zeta valence quality for atoms Li to Kr. J. Chem. Phys. 100, 5829–5835 (1994).

    Article  ADS  Google Scholar 

  39. Grimme, S., Antony, J., Ehrlich, S. & Krieg, H. A consistent and accurate ab initio parametrization of density functional dispersion correction (DFT-D) for the 94 elements H–Pu. J. Chem. Phys. 132, 154104–154119 (2010).

    Article  ADS  Google Scholar 

  40. Grimme, S., Ehrlich, S. & Goerigk, L. Effect of the damping function in dispersion corrected density functional theory. J. Comput. Chem. 32, 1456–1465 (2011).

    Article  CAS  Google Scholar 

  41. Glendening, E. D. et al. NBO v. 5.9 (2011).

    Google Scholar 

  42. Dennington, R., Keith, T. A. & Millam, J. M. GaussView v. 5.0 (Semichem Inc., 2009).

Download references

Acknowledgements

This work was supported by the SCG-Oxford Centre of Excellence. P.V. thanks the Magnus Ehrnrooth and Emil Aaltonen Foundations for postdoctoral funding. We thank the University of Oxford Advanced Research Computing facility, and N. Rees and H. Tuononen for assistance with NMR and quantum chemical studies, respectively.

Author contributions J.H. carried out the synthetic and reaction studies, P.V. carried out the computational analyses, J.H. and J.M.G. conducted the crystallographic studies, and J.M.G. and S.A. wrote the manuscript and managed the project.

Competing interests: The authors declare no competing interests.

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Authors and Affiliations

  1. Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, UK

    Jamie Hicks, Petra Vasko, Jose M. Goicoechea & Simon Aldridge

  2. Department of Chemistry, NanoScience Center, University of Jyväskylä, Jyväskylä, Finland

    Petra Vasko

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  1. Jamie Hicks
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Correspondence to Jose M. Goicoechea or Simon Aldridge.

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Extended data figures and tables

Extended Data Fig. 1 Molecular structure of (NON)AlI as determined by X-ray crystallography.

Hydrogen atoms have been omitted and selected carbon atoms shown in wireframe format for clarity; thermal ellipsoids have been drawn at the 35% probability level. Key bond lengths (Å) and angles (°): Al(1)–I(1) 2.497(1), Al(1)–N(1) 1.846(2), Al(1)–N(2) 1.846(2), Al(1)–O(1) 1.967(2), N(1)–Al(1)–N(2) 143.0(1).

Extended Data Fig. 2 Molecular structure of [Al(NON)]2 as determined by X-ray crystallography.

Hydrogen atoms have been omitted and selected carbon atoms shown in wireframe format for clarity; thermal ellipsoids have been drawn at the 35% probability level. Key bond lengths (Å) and angles (°): Al(1)–Al(2) 2.646(1), Al(1)–N(1) 1.902(2), Al(1)–N(2) 1.895(2), Al(2)–N(3) 1.901(2), Al(2)–N(4) 1.900(2), Al(1)–O(1) 1.976(2), Al(2)–O(2) 1.981(2), N(1)–Al(1)–N(2) 119.0(1), N(3)–Al(2)–N(4) 118.6(1).

Extended Data Fig. 3 Molecular structure of one of the molecules in the asymmetric unit of [K{H2Al(NON)}]2 as determined by X-ray crystallography.

Second (essentially identical) component, benzene solvate molecules and carbon-bound hydrogen atoms have been omitted and selected carbon atoms shown in wireframe format for clarity; thermal ellipsoids have been drawn at the 35% probability level. Key distances (Å) and angles (°): Al(1)–N(1/2) 1.933(2)/1.921(2), Al(2)–N(3/4) 1.934(2)/1.917(2), Al(1)–O(1) 2.131(1), Al(2)–O(2) 2.124(2), Al(1)…Al(2) 6.356(1), Al(1)…K(1/2) 3.648(1)/4.065(1), Al(2)…K(1/2) 3.580(1)/4.039(1), Al(1)–H(1 A/1B) 1.69(4)/1.55(4), Al(2)–H(2 A/2B) 1.71(4)/1.58(4), N(1)–Al(1)–N(2) 130.3(1), N(3)–Al(2)–N(4) 131.1(1).

Extended Data Fig. 4 Infrared spectra of [K{Al(NON)}]2 and [K{H2Al(NON)}]2.

a, [K{Al(NON)}]2. b, [K{H2Al(NON)}]2. Both spectra have been measured on samples as Nujol mulls; the blue asterisk highlights the Al–H stretching band of [K{H2Al(NON)}]2.

Extended Data Fig. 5 Molecular structure of [K{Ga(NON)}]2 as determined by X-ray crystallography.

Hydrogen atoms have been omitted and selected carbon atoms shown in wireframe format for clarity; thermal ellipsoids have been drawn at the 35% probability level. Key bond lengths and distances (Å) and angles (°): Ga(1)…Ga(1′) 6.134(1), Ga(1)…K(1) 3.970(1), Ga(1)…K(1′) 3.784(1), Ga(1)–N(1) 2.093(2), Ga(1)–N(2) 2.106(2), Ga(1)–O(1) 2.542(2), N(1)–Ga(1)–N(2) 126.0(1).

Extended Data Fig. 6 Molecular structure of (NON)AlH·toluene as determined by X-ray crystallography.

Most hydrogen atoms have been omitted and selected carbon atoms shown in wireframe format for clarity; thermal ellipsoids have been drawn at the 35% probability level. Key bond lengths (Å) and angles (°): Al(1)–N(1) 1.873(1), Al(1)–N(2) 1.872(1), Al(1)–O(1) 1.944(1), Al(1)–H(1) 1.49(2), N(1)–Al(1)–N(2) 134.1(1).

Extended Data Fig. 7 Molecular structure of [K{Ph(H)Al(NON)}]2 as determined by X-ray crystallography.

Most hydrogen atoms and benzene solvate molecules have been omitted, and selected carbon atoms shown in wireframe format for clarity; thermal ellipsoids have been drawn at the 35% probability level. Key bond lengths (Å) and angles (°): Al(1)–N(1) 1.945(2), Al(1)–N(2) 1.944(2), Al(1)–O(1) 2.122(1), Al(1)–C(48) 2.007(1), Al(1)–H(1) 1.82(3), N(1)–Al(1)–N(2) 132.2(1).

Extended Data Table 1 Selected X-ray data collection and refinement parameters for complexes prepared in this study
Full size table

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Hicks, J., Vasko, P., Goicoechea, J.M. et al. Synthesis, structure and reaction chemistry of a nucleophilic aluminyl anion. Nature 557, 92–95 (2018). https://doi.org/10.1038/s41586-018-0037-y

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