TY - JOUR
T1 - Dimerization versus complexation of triethylaluminum and diethylaluminum chloride
T2 - An ab initio determination of structures, energies of formation, and vibrational spectra
AU - Champagne, Benoît
AU - Mosley, David H.
AU - Fripiat, Joseph G.
AU - André, Jean-Marie
AU - Bernard, Albert
AU - Bettonville, Serge
AU - François, Philippe
AU - Momtaz, Ardéchir
PY - 1998/11/28
Y1 - 1998/11/28
N2 - Ab initio Hartree-Fock, density functional and Møller-Plesset schemes are adopted to characterize the geometrical structures, energies of formation and infrared spectra of dimers of diethylaluminum chlorine (DEAC) and triethylaluminum (TEAL), and their complexes formed with dimethylether. This is the first theoretical approach which shows that ethyl-bridged aluminum compounds are stable with respect to dissociation; electron correlation effects being large and necessary for assessing the stability of the ethyl bridges. For the dimer of TEAL, the MP2/6-31G* estimate, corrected for the BSSE via the counterpoise scheme and including the ZPVE correction, is in close agreement with experimental data. This study shows that pure TEAL and DEAC are present under the dimeric form but they react with ethers to form more stable co-catalyst/ether complexes. The new infrared bands appearing on the formation of dimers and complexes are discussed. It turns out that combining far-infrared spectroscopy and quantum-chemical calculations can help in identifying uniquely the structure of alkylaluminum chloride dimers and also their possible complexation by ethers.
AB - Ab initio Hartree-Fock, density functional and Møller-Plesset schemes are adopted to characterize the geometrical structures, energies of formation and infrared spectra of dimers of diethylaluminum chlorine (DEAC) and triethylaluminum (TEAL), and their complexes formed with dimethylether. This is the first theoretical approach which shows that ethyl-bridged aluminum compounds are stable with respect to dissociation; electron correlation effects being large and necessary for assessing the stability of the ethyl bridges. For the dimer of TEAL, the MP2/6-31G* estimate, corrected for the BSSE via the counterpoise scheme and including the ZPVE correction, is in close agreement with experimental data. This study shows that pure TEAL and DEAC are present under the dimeric form but they react with ethers to form more stable co-catalyst/ether complexes. The new infrared bands appearing on the formation of dimers and complexes are discussed. It turns out that combining far-infrared spectroscopy and quantum-chemical calculations can help in identifying uniquely the structure of alkylaluminum chloride dimers and also their possible complexation by ethers.
KW - Alkylaluminums
KW - Complexation by Lewis bases
KW - Dimerization
KW - Energies of reaction
KW - Vibrational spectra
UR - http://www.scopus.com/inward/record.url?scp=0006017978&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0006017978
SN - 0166-1280
VL - 454
SP - 149
EP - 159
JO - Journal of Molecular Structure: THEOCHEM
JF - Journal of Molecular Structure: THEOCHEM
IS - 2-3
ER -