טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentBendikov Michael
SubjectSilenes - Synthesis, Reaction Mechanisms and Theory
DepartmentDepartment of Chemistry
Supervisor ? 18? Yitzhak Apeloig


Abstract

Much attention has been devoted in recent years to silenes, yet relatively little is known about their properties, the reaction mechanisms by which they are formed or on the mechanisms of their reactions. Fundamental issues such as structure-reactivity and reactivity-selectivity relationships are still open questions. Theoretical investigations have played a very important role in the study of silenes and much of our fundamental knowledge on this class of compounds comes from quantum mechanical calculations.

In this work we have concentrated our efforts on the study of the following issues:

(1)     Understanding the electronic structure of silenes.

(2)     Understanding the mechanisms by which silenes react.

(3)     Understanding the factors which control silene reactivity.

We studied theoretically using modern quantum mechanical methods the following specific projects:

1.        Addition of nucleophiles to silenes. A theoretical study of the effect of substituents on the kinetic stability and the regioselectivity of addition.

2.        Addition of water and alcohols to silenes of the type (R3Si)2Si=2-Ad - a real experimental system.

3.        Cycloaddition reactions of silenes: [4+2] vs. [2+2].

4.        Chemical shielding tensors of a silicon-carbon double bond.

5.        The trichlorovinylsilane / t-butyllithium reagent - a source for transient silenes?

6.        Mono, di and trisilafullerenes. A DFT study of structures and stabilities.

7.        Ionization energies of silenes.

8.        Theoretical study of the first stable organic radical lacking resonance stabilization.