Syntheses and Crystal Structures of Sr7H12X2 (X = Cl, Br)

Dichroic, pink to blue single crystals of Sr Cl and Sr Br were obtained by reacting Sr with SrX or NaX and NaNH or NH X (X = Cl, Br) as hydrogen sources in a Na melt at 900 °C for 12 h in silica-jacketed stainless-steel or Ta ampoules. The crystal structures of the new compounds were determined by means of single crystal X-ray diffraction. Both title compounds crystallize isotypically to Ba Cl in the hexagonal space group P6̅ (no. 174) with the lattice parameters a = 998.06(3), c = 392.84(3) pm for Sr Cl and a = 1004.62(3), c = 399.68(3) pm for Sr Br . The hydride positions taken from the difference Fourier map agree with those of the fluorides of the isotypic compound Ba Cl . The validity of our structural results is corroborated by EUTAX calculations and the comparison to SrH , SrX and SrHX.