ChemInform Abstract: NMR Spectroscopic Investigations on the Constitution of Benzyl and 1-Naphthylmethyl Compounds of Titanium, Zirconium, and Hafnium.
Abstract
1H and 13C NMR spectra of (I) and the analogous compounds (II) do not indicate special bonding properties which are supposed to exist on the basis of X-ray analyses of (I).
ChemInform Abstract
1H and 13C NMR spectra of (I) and the analogous compounds (II) do not indicate special bonding properties which are supposed to exist on the basis of X-ray analyses of (I). On exchanging benzyl groups in (Ia) with halogen atoms, compounds (III) are formed having an alternated electron density at the metal atoms as indicated by the δ(CH2) values but not by chemical shifts in the Ph group, which is evident in (IV). While in (I) a η4-coordination of the benzyl group, caused by delocalization of the negative charge, is assumed, these groups are η1-bonded in (IV). An alternation of the coordination system is shown to exist in the case of (Ib) and (IIb) in the presence of donor molecules such as Py and THF.
