Premium
The Electronic Structure of the Tris(ethylene) Complexes [M(C 2 H 4 ) 3 ] (M=Ni, Pd, and Pt): A Combined Experimental and Theoretical Study
Author(s) -
Hebben Nicole,
Himmel HansJörg,
Eickerling Georg,
Herrmann Carmen,
Reiher Markus,
Herz Verena,
Presnitz Manuel,
Scherer Wolfgang
Publication year - 2007
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200700885
Subject(s) - raman spectroscopy , ligand (biochemistry) , molecule , ethylene , spectral line , chemistry , platinum , electronic structure , density functional theory , crystallography , molecular vibration , materials science , physics , computational chemistry , quantum mechanics , catalysis , organic chemistry , receptor , biochemistry
Abstract In this article we analyze in detail the electronic properties of the D 3 h ‐symmetric tris(ethylene) complexes of nickel, palladium, and platinum ([M(C 2 H 4 ) 3 ] M=Ni, Pd, Pt). In the case of [Pd(C 2 H 4 ) 3 ] the analysis is based on new experimental IR and Raman spectra for the matrix‐isolated molecules and in all cases on the results of quantum‐chemical (DFT) calculations. The experimental spectra collected for [Pd(C 2 H 4 ) 3 ] provide evidence for several previously unobserved vibrational modes, including the in‐phase and out‐of‐phase ν(CC) and δ (CH 2 ) modes, and the in‐phase ν(MC) mode. Special consideration is given to possible inter‐ligand interactions. The interaction force constant f CC,CC between two C 2 H 4 ligands can be directly estimated from the spectra, and its very small value (0.002 N m −1 ) indicates the absence of any significant inter‐ligand interaction. An analysis of the topology of the theoretical electron density distribution, ρ ( r ), and the corresponding Laplacian, ∇ 2 ρ ( r ), for [Pd(C 2 H 4 ) 3 ] and its lighter and heavier homologues [Ni(C 2 H 4 ) 3 ] and [Pt(C 2 H 4 ) 3 ], respectively, is in full agreement with the conclusions drawn from the experimental results. The combined experimental and quantum‐chemical results provide detailed insights in the electronic properties of these prototypical ethylene complexes.