Group 6 metal bis(benzene) sandwich complexes (M- bz2: M=Cr, Mo, and W and bz= C6 H6) were produced with laser vaporization molecular beam techniques and studied by pulsed-field ionization zero electron kinetic energy spectroscopy and density functional theory calculations. Each sandwich complex is in a D6h eclipsed configuration with A 1g 1 and A 1g 2 as the neutral and cationic ground electronic states, respectively. The adiabatic ionization energies for Cr-, Mo-, and W- bz2 are measured to be 44 081(7), 44 581(10), and 43 634 (7) cm-1, respectively. The metal-benzene stretch and benzene torsion frequencies of the ion are measured to be 264, 277, and 370 cm-1 and 11, 21, and 45 cm-1 for Cr-, Mo-, and W- bz2, respectively. In addition, a C-H out-of-plane bending mode is measured to be 787 cm-1 for the Cr+ - bz2 complex, while a C-C in-plane bending mode is measured to be 614 cm-1 for the W+ - bz2 complex. The unusual trend in the ionization energy and metal-benzene stretch frequency indicates strong relativistic effects on tungsten binding.
|Journal||Journal of Chemical Physics|
|State||Published - Apr 7 2006|
Bibliographical noteFunding Information:
This work was supported by the National Science Foundation and the donors of the Petroleum Research Fund of the American Chemical Society. The Kentucky Science and Engineering Foundation is also acknowledged for partial support of this paper.
ASJC Scopus subject areas
- Physics and Astronomy (all)
- Physical and Theoretical Chemistry