A Theoretical Investigation of the Nonrigid Six‐Coordinate Compounds [Mo(R)F 5 ], [W(R)F 5 ], and Related Compounds

Density functional calculations for [M(CH 3 )F 5 ], [M(CF 3 )F 5 ], [M(CH 3 S)F 5 ], and [M(CF 3 S)F 5 ] (M=Mo, W) show that they are expected to be nonrigid molecules, with energy barriers for the octahedral–trigonal‐prismatic interchange as low as 7.2 kJ mol −1 . The ground state for the CH 3 and CF 3 compounds is trigonal prismatic, for the CH 3 S and CF 3 S compounds, (distorted) octahedral. All calculated compounds [M(C 6 F 5 ) n F 6− n ] (M=Mo, W) have a trigonal‐prismatic ground state, whereas the situation for [M(C 6 H 5 ) n F 6− n ] (M=Mo, W) is more complex.