76830-91-6Relevant academic research and scientific papers
Kinetics and Mechanisms of Carbonyl Substitution Reactions of Bis(η5-cyclopentadienyl) Dicarbonyl Compounds of the Titanium Triad Metals
Palmer, G. Todd,Basolo, Fred,Kool, Larence B.,Rausch, Marvin D.
, p. 4417 - 4422 (2007/10/02)
Kinetic studies were performed for CO substitution reactions of (η5-ring)2M(CO)2, where (η5-ring)=Cp, Cp*, or Ind and M=Ti, Zr, or Hf.Nucleophiles used for these reactions include PMe2Ph, PMePh2, PPh3, P(n-Bu)3, and CO.The reaction rates of the titanium compounds were first order in substrate and zero order in entering nucleophile at nucleophile concentrations which gave the limiting reaction rate.The results indicate a dissociative mechanism.Activation parameters for these reactions are also in agreement with a dissociative process.In contrast, reaction rates of the zirconium and hafnium compounds are first order in both substrate and entering nucleophile, indicating an associative mechanism.This mechanistic difference may be attributed to steric considerations caused by the smaller size of titanium.Equilibrium constants and rate constants indicate a strong preference of the Ti, Zr, and Hf metallocene compounds for CO over PR3.
FORMATION REACTIVITIES, AND MOLECULAR STRUCTURES OF PHOSPHINE DERIVATIVES OF TITANOCENE - ISOLATION AND CHARACTERIZATION OF A TITANIUM MONOOLEFIN pi COMPLEX.
Edwards,Rogers,Sikora,Atwood,Rausch
, p. 416 - 426 (2007/10/02)
The synthesis of several new phosphine derivatives of titanocene under both thermally and photochemically induced conditions are described. The molecular structures of two of these complexes have been elucidated by means of single-crystal X-ray diffraction methods, and the bonding modes of the respective phosphine ligands to titanium are compared. Finally, the utility of the triethylphosphine analogue as a versatile intermediate for the generation of pi -acetylenic and pi -monoolefinic complexes of titanium is reported. Refs.
