Synthetic and Structural Investigations of Dinitrogen, Carbonyl, Olefin, Dichloride, and Hydride Derivatives of Bis(Pentamethylclopentadienyl)Titanium and Zirconium

Author: Sanner, Robert D.

Year: 1978

Degree: Dissertation (Ph.D.)

Advisor: Bercaw, John E.

Committee Member: Unknown, Unknown

Option: Chemistry

DOI: 10.7907/bjmq-3010

Abstract

The crystal structures of three compounds containing the (η5 -C5Me5)2M (M = Ti, Zr) moiety have been determined by single crystal X-ray diffraction methods. (η5 -C5Me5)2 TiCl2 has a distorted tetrahedral configuration about titanium comprised of the two chlorine atoms and the centroids of the two η5 -C5Me5 rings. Several ring methyl groups are bent considerably out of the cyclopentadienyl plane away from titanium due to chlorine methyl and inter-ring methyl-methyl crowding. The final R factor was 0. 032. The structure of {(η5 -C5Me5)2Ti}2N2 consists of two (η5 -C5Me5)2Ti moieties bridged by N2 in a linear Ti-N≡N-Ti arrangement. The final R index was 0.058. A qualitative molecular orbital treatment of the bonding consistent with the structure is presented. The structure of {(η5 -C5Me5)2ZrN2}2N2 consists of two (η5 -C5Me5)2ZrN2 subunits bridged by a third dinitrogen ligand. Terminal and bridging dinitrogen ligands are bound end-on to zirconium with essentially linear Zr-N≡N and Zr-N≡N-Zr arrangements. The final R factor was 0. 035. A qualitative picture of the zirconium-dinitrogen bonding consistent with the structure and other physical properties of the compound is presented.

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