AbstractA number of compounds of the general formula M(NIPA)n(anion)mis reported, in which M = Mg,Ca,Sr,Ba,Al,Cr,Fe and In; NIPA = nonamethylimidodiphosphoramide { = [(CH3)2N]2P(O)N(CH3)P(O)[N(CH3)2]2}, n = 1‐3, m = 2,3 and the anions are BF−4, Cl−, Br−, I−, NO−3and NCS−.The compounds are characterized by chemical analyses and physical measurements.With the aid of infrared and ligand‐field spectra in combination with X‐ray powder patterns octahedrally coordinated metal ions are found in all compounds.The ligand is shown, by means of infrared spectroscopy, to coordinateviathe oxygen lone pair electrons to the metal ions investigated.Metal‐ligand stretching frequencies are observed in the 700 − 450 cm−1region for the trivalent metal compounds. The absence of these bands in the spectra of the bivalent metal complexes is explained in terms of the high ionic character of the metal‐ligan