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A series of neutral, bulky diazabutadienediyl-substituted beryllacycles [Be(DipDAB)(L)] (DipDAB = [(DipNCH)2]2-, Dip = 2,6-diisopropylphenyl; L = OEt2, THF,:C(RNCH)2; R = Me (TMC), Pri (IPriMe)) have been prepared and characterized by multinuclear NMR spectroscopy and X-ray crystallography. The preparation of similar complexes bearing the smaller tert-butyl-substituted diazabutadienediyl ligand ([(ButNCH)2]2-, viz. ButDAB) was attempted but gave rise to complex product mixtures, several components of which were isolated in trace yields. This phase of the study did, however, lead to the preparation of the homoleptic beryllium diradical complex [Be(ButDAB•)2], which was characterized by X-ray crystallography and EPR spectroscopy. In efforts to access BeI-BeI-bonded dianions, [(DipDAB)Be-Be(DipDAB)]2-, reductions of [Be(DipDAB)(L)] were pursued, but these instead afforded largely intractable product mixtures. Treating ethereal solutions of [Be(DipDAB)(OEt2)] with lithium alkyls afforded highly reactive, heterocyclic beryllate salts, [Li(OEt2)2,1][Be(DipDAB)R] (R = Me, Bun). Subsequent treatment of [Li(OEt2)][Be(DipDAB)Bun] with either N,N,N′,N′-tetramethylethylenediamine (tmeda) or N,N,N′,N′′,N′′-pentamethyldiethylenetriamine (pmdeta) led to the formation of [Li(tmeda)2][Be(DipDAB)Bun] and [Li(pmdeta)][Be(DipDAB)Bun]. Reactions between two of the heterocyclic beryllate salts and [BeX2(OEt2)2] (X = Br, I) did not lead to clean salt metathesis reactions but gave mixtures of many products, several of which were isolated in very low yields. While the noninnocent nature of the diazabutadienediyl ligands of [Be(DipDAB)(L)], and the [Be(DipDAB)R]- anions, hampered explorations of their further reactivity, these heterocycles hold promise as synthons for beryllium coordination chemistry.
|Number of pages||6|
|Publication status||Published - 14 Dec 2020|
- 1 Finished
A National Biomedical Electron Paramagnetic Resonance and Molecular Imaging Centre
Schmidt, H., Barnham, K. J., Best, S., Bond, A., Boskovic, C., Donnelly, P. S., Gahan, L., Hanson, G. R., Langford, S., Martinac, B., Masters, C. L., McGrath, B., Morgan, M., Murray, K., Parkington, H., Riley, M., Schenk, G., Selemidis, S., Separovic, F., Spiccia, L., Thompson, M., Tuck, K., Wedd, A., Wingler, K. & Young, C.
Australian Research Council (ARC), Monash University, University of Melbourne, University of Queensland
20/09/07 → 31/12/09