Occurrence of mixed tetrahaloaluminate ions shown by aluminum-27 nuclear magnetic resonance spectroscopy

Syntheses and Characterization of Salts with the [Al(D)4F2]+ Cation (D = Pyridine or Water)

“…23−25 That attends a larger electric field gradient and a larger QCC value for the Al nucleus in AlBr 3 as in AlI 3 . Consequently, the central part of the experimental 27 Al MAS NMR spectrum of AlBr 3 is much broader compared with the corresponding spectrum of 29 Solid state 27 Al NMR studies confirmed these results. For a large number of oxygen coordinated aluminum compounds typical ranges for hexa-, penta-and tetracoordinated aluminum have been obtained.…”

“…The comparison of the isotropic 27 Al chemical shift values between (AlI 3 ) 2 and "AlI 3 ·3Py" shows a change to lower fields from −23.7 ppm for the starting compound to 20.8 ppm for the final product. In our studies of AlCl 3 −pyridine complexes, we found that a substitution of chlorine by pyridine in the first coordination sphere of aluminum leads to a low-field shift of the 27 Al chemical shift for tetrahedrally as well as for octahedrally coordinated aluminum.…”

“…3 MHz for 27 Al, 161.9 MHz for 31 P and 376.4 MHz for 19 F. The MAS NMR measurements were performed using a 4 mm and a 2.5 mm double-bearing triple resonance ( 1 H/ 19 F−X) MAS probe (Bruker Biospin) at spinning rates between 12 and 15 kHz and between 25 and 30 kHz, respectively. The 27 Al MAS spectra were obtained using single pulse excitation with pulse durations of 1 μs (π/12 pulses). For a reliable signal-to-noise ratio the spectra were recorded by accumulating up to 72 800 scans with a recycle delay of 1s.…”

“…The product of the reaction between [Al(Py) 4 F 2 ]Cl and the trimeric phosphonic acid anhydride [CH 3 CH 2 CH 2 −PO 2 ] 3 was additionally studied by 31 27 Al. The NMR parameters (chemical shifts, line widths, quadrupolar coupling constants) were fitted to the experimental spectra using the Topspin software (Bruker Biospin) and the dmfit 15 software package.…”

“…For a large number of oxygen coordinated aluminum compounds typical ranges for hexa-, penta-and tetracoordinated aluminum have been obtained. 30 Furthermore, influences of the second coordination sphere on the 27 Al chemical shifts of oxygen coordinated aluminum were established and correlations between structural data and the 27 Al chemical shift values were reported. 31,32 Besides the oxygen coordinated aluminum compounds also such with other ligands have been studied by solid-state 27 Al NMR spectroscopy, among them halogen coordinated ones.…”