Structures and its dipole moments of half-sandwich type metal-benzene (1:1) complexes determined by 2-m long electrostatic hexapole

The transition metal-benzene (1:1) complexes are synthesized by laser evaporation method followed by the size and structure selection with 2-m long electrostatic hexapole field. Electric dipole moments of half-sandwich type binary complexes for a series of the transition metals, i.e. Ti, V, Co, and Ni, with benzene molecule were determined by measuring the focusing curves, namely the dependence of the focused beam intensity upon the hexapole field strength. It is found that the dipole moments of Ti-C₆H₆ and V-C₆H₆ are larger than the ones of Co-C₆H ₆ and Ni-C₆H₆. Such large dipole moments of Ti-C₆H₆ and V-C₆H₆ can be ascribed to the strong orbital interaction due to charge transfer between the metal atom and benzene molecule.