NH3 free rotors in Hofmann clathrates

Abstract We have studied the effect on NH 3 rotation of changing the M I metal in the Hofmann clathrates M I (NH 3 ) 2 Ni(CN) 4 .2C 6 D 6 where M I = Cu, Fe, Mn, Ni, Zn. Only slight changes in the energy of the NH 3 rotor peak are observed. In contrast, the empty host compound Ni(NH 3 ) 2 Ni(CN) 4 shows a marked increase in the rotational barrier.