Synthese und Charakterisierung von Cp2* M(DAD)-Komplexen (M=Y oder La): Molekuelstruktur von Cp2* Y

Article abstract of DOI:10.1016/0022-328X(95)05646-7

The treatment of (η⁵-C5Me5)2La(μ-Cl)2K(dme)₂ (3) with an equimolar amount of Na2(DAD) in the presence of DAD or with two equivalents of Na(DAD) results in the formation of the ionic complex <(η⁵-C5Me5)2La(DAD)> (4), which has been characterized by IR and NMR spectroscopy.Complex 4 exhibits dynamic NMR spectra indicating rapid migration of the (η⁵-C5Me5)2La unit from one side of the reduced DAD ligand to the other. (η⁵-C5Me5)2Y(μ-Cl)2Li(OEt2)2 (5) reacts with Na(DAD) to yield dark-red crystals of the complex (η⁵-C5Me5)2Y(DAD) (6).Complex 6 is monoclinic, of space group C2/c (No. 15), with Z=4, with a=1345.2(3), b=1702.9(2) and c=1811.3(2) pm and with β=106.73(1) deg.The structure was refined to R=0.040 for 2399 observed reflections (F₀>4?(F₀)).The DAD ligand in 6 is reduced to the radical anion and forms a planar five-membered Y(N-C-C-N) ring.Keywords: Organoyttrium compounds; Diazadiene complexes; X-ray structure investigation