A novel high-yield route to organic derivatives of group 2 metals; X-ray structure of [{Ba(OTf)2}4(py)14]·py (OTf = OSO2CF3) and NMR spectral characterisation of [Ba(NR2)(µ-NR2)2Na(thf)2](R = SiMe3)
Abstract
Treatment of M(OTf)2[from MO + 2 HOTf; OTf = OSO2CF3 and M = Ca 1, Sr 2 or Ba 3] with 2MOAr or 2MNR2(M = Na or K, Ar = C6H2But2-2,6-Me-4; R = SiMe3) in thf at 0 °C affords [Ca(OAr)2(thf)3]4, [M(OAr)2(thf)4](M = Sr 5 or Ba 6), [M(NR2)2(thf)2](M = Ca 7 or Sr 8) or [Ba(NR2)(µ-NR2)2Na(thf)2]9; the new compounds 1–3 have been characterised by their NMR spectra in pyridine, and the pyridine adduct of 3 also by X-ray diffraction: crystalline [Ba4(η2-OTf)2(µ-OTf)2(µ3-OTf)4(py)14]·py 10 is unique among metal triflates in having three different bonding modes for the –OTf ligand.