THESIS
2013
xiii, 52 pages : illustrations ; 30 cm
Abstract
The thermodynamic and kinetic aspects of the rearrangement reactions of a series of
metallabenzenes to cyclopentadienyl complexes have been investigated by DFT computational
study in order to reveal how substituents on the metallacycle, ligands around the metal center, and
metals affect the transformation. It was found that metals, substitutents and their locations on the metallacycle have a significant effect on the thermodynamics and kinetics of the rearrangement
reactions. The effect of ligands is less important.
The electrophilic substitution reaction of the metallabenzyne
Os(≡CC(R)=C(CH
3)C(R)=CH)Cl
2(PPh
3)
2 (R = SiMe
3) with NO
2BF
4 has been studied
theoretically. Experimentally, the reaction produced an expected normal osmabenzyne complex
and an unexpected paramagnetic carbe...[
Read more ]
The thermodynamic and kinetic aspects of the rearrangement reactions of a series of
metallabenzenes to cyclopentadienyl complexes have been investigated by DFT computational
study in order to reveal how substituents on the metallacycle, ligands around the metal center, and
metals affect the transformation. It was found that metals, substitutents and their locations on the metallacycle have a significant effect on the thermodynamics and kinetics of the rearrangement
reactions. The effect of ligands is less important.
The electrophilic substitution reaction of the metallabenzyne
Os(≡CC(R)=C(CH
3)C(R)=CH)Cl
2(PPh
3)
2 (R = SiMe
3) with NO
2BF
4 has been studied
theoretically. Experimentally, the reaction produced an expected normal osmabenzyne complex
and an unexpected paramagnetic carbene complex. The theoretical study helps to clarify the
mechanism of the reaction.
Some metallabenzynes could undergo migratory insertion reactions to give carbene
complexes, while other structurally related metallabenzynes do not undergo the same kind
reaction. A subtitle change in the substituents in the metallacycle can have a drastic effect on the
transformation. A theoretical study suggests that the substituent effect is related to steric effect.
The aromatic property of rhenabenzynes and osmabenzynes have been evaluated by the
aromatic stabilization energy (ASE) and nucleus-independent chemical-shift (NICS) values. The
results suggest that these metallabenzynes have aromatic character.
Post a Comment