Geometry and electronic structure of bis(tetrahydridoborato)bis(cyclopentadienyl)zirconium(IV)

The geometry and the electronic structure of the title compound was investigated by UV photoelectron spectroscopy, X-ray diffraction and ab initio quantum-chemical methods. The photoelectron spectrum was recorded both at He(I) and He(TI) photon energies, which was assigned on the basis of the quantum-chemical calculations and comparison with analogous complexes. Full geometry optimization was performed at the Hartree-Fock and at the second-order many-body perturbation levels of theory. The obtained geometry is in good agreement with the anticipated bidentate ligation of the BH, groups. The measured Zr-B distance from the X-ray studies provides further evidence for the above mentioned bonding mode of the tetrahydridoborato ligands. The ionization energies of the complex were calculated using the outer valence Green's function method. (C) 1999 Elsevier Science S.A. All rights reserved.