An extended X-ray absorption fine structure study of penta-amminecopper(II) bis(tetrafluoroborate): evidence for five equal bond lengths

The extended X-ray absorption fine structure spectra of powered [Cu(NH3)5][BF4]2 have been measured at room temperature and at 77 K using synchrotron radiation. Standard Fourier-transform and least-squares fitting methods {utilising [Cu(en)2][BF4]2(en = ethylenediamine) as a model complex for extracting amplitude and phase parameters for Cu–N bonds} demonstrate that in each case only a single shell is present about the metal ion, i.e. all five Cu–N bonds are of equal length.