Variable photon energy photoelectron spectroscopic studies of covalent bonding in 3d/sup 10/ transition-metal compounds

Journal Article · Wed Jun 29 04:00:00 EDT 1988 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00286a008· OSTI ID:5976303

Didziulis, S V; Cohen, S L; Butcher, K D; Solomon, E I

Variable photon energy photoelectron spectroscopy (PES) is used to determine the valence band electronic structure and to study the covalent bonding properties of three tetrahedral, 3d/sup 10/ transition-metal complexes with /sigma/-donor, /pi/-donor ligands: ZnO, ZnCl/sub 4//sup 2/minus//, and CuCl. PES data obtained over the photon energy range of 16.7-1486.6 eV show dramatic intensity changes of valence band features that are caused by changes in photoionization cross sections and resonance effects at the metal 3p absorption edge. Intensity changes with photon energy allow detailed assignments of spectra to be made by using molecular orbital theory. Analyses of the peak intensities and binding energies provide a measure of the covalent bonding. Larger ZnO 3d band splitting relative to that for ZnCl/sub 4//sup 2/minus// indicates greater ligand field strength (10Dq) for the oxide ligands, which arises from the stronger /sigma/-bonding interactions of the Zn/sup 2+/ 3d with the O/sup 2/-2p orbitals. The increased effective nuclear charge on Zn/sup 2+/ shifts the d levels below the ligand levels, making them bonding and reversing the sign of the tetrahedral 10Dq value. This greater effective nuclear charge on Zn/sup 2+/ also significantly lowers the energy of the empty metal 4s and 4p levels, resulting in greater covalent stabilization of the ligand bonding levels in ZnCl/sub 4//sup 2/minus// than in CuCl. The relative contributions of ionic and covalent bonding in ZnCl/sub 2/ and CuCl are examined and related to the much greater thermodynamic stability of Zn/sup 2+/ complexes with donor ligands. 74 references, 13 figures, 5 tables.

• Research Organization: Stanford Univ., CA (USA)
• OSTI ID: 5976303
• Journal Information: Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 27:13; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CHALCOGENIDES
CHLORIDES
CHLORINE COMPOUNDS
COPPER CHLORIDES
COPPER COMPOUNDS
COPPER HALIDES
DATA
ELECTRON SPECTROSCOPY
ELECTRONIC STRUCTURE
EXPERIMENTAL DATA
HALIDES
HALOGEN COMPOUNDS
INFORMATION
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
SPECTROSCOPY
TRANSITION ELEMENT COMPOUNDS
VALENCE
ZINC CHLORIDES
ZINC COMPOUNDS
ZINC HALIDES
ZINC OXIDES