81Br NQR and 119Sn Mössbauer Spectra for SnBr3− Anions

Abstract

Abstract The structures of the SnBr3− anions in MSnBr3 (M=(CH3)2NH2, (CH3)3NH) and MSnBr3·H2O (M=K, NH4) were deduced by means of 81Br NQR spectroscopy. The former compounds have three 81Br NQR lines in the frequency range 73–80 MHz at 77 K, indicating the presence of pyramidal SnBr3− anions. The anion structure of the latter hydrate, on the other hand, was presumed to be square-pyramid with one terminal and two bridging Br atoms, because two of the 81Br NQR frequencies were considerably low compared with that of the terminal atom. Phase transitions were observed for the latter hydrates. Associated with these, drastic increases of the NQR frequencies were observed only for the bridging atoms, suggesting significant changes in the bridging network.